From daileyservices at qwest.net  Wed Jan  1 00:47:32 2014
From: daileyservices at qwest.net (TC Dailey)
Date: Tue, 31 Dec 2013 22:47:32 -0700
Subject: [HBR] HBR parts for swap
References: <02a601cf0699$70409f80$50c1de80$@net> <52C37FCF.4080906@gmail.com>
Message-ID: <FE1853E8164643C0960D65068228F75C@w0eaj>

Bill C.

I have a BRAND NEW National ACN dial, NIB... original box, original dial
 $30 plus post

Tom - W?EAJ - Denver



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From bignick at execpc.com  Wed Jan  1 08:35:49 2014
From: bignick at execpc.com (bignick at execpc.com)
Date: Wed, 1 Jan 2014 08:35:49 -0500 (EST)
Subject: [HBR] HBR parts for swap
In-Reply-To: <FE1853E8164643C0960D65068228F75C@w0eaj>
References: <02a601cf0699$70409f80$50c1de80$@net>
	<52C37FCF.4080906@gmail.com> <FE1853E8164643C0960D65068228F75C@w0eaj>
Message-ID: <63937.24.209.127.165.1388583349.squirrel@webmail.core.com>



Bill,

You still have it?

I'm interested.

-tom

KC9KEP

> Bill C.
> 
> I
have a BRAND NEW National ACN dial, NIB... original box, original dial
>  $30 plus post
> 
> Tom - W?EAJ - Denver
> 
> 
> 
> ---
> This email is free
from viruses and malware because avast! Antivirus
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From Hopperdhh at aol.com  Wed Jan  1 09:11:33 2014
From: Hopperdhh at aol.com (Hopperdhh at aol.com)
Date: Wed, 1 Jan 2014 09:11:33 -0500 (EST)
Subject: [HBR] WTB coil forms
Message-ID: <53cb2.71064597.3ff57c15@aol.com>


Hi Bill,
 
I found my Boonton Q-Meter in a local scrap yard, and bought it for (I  
think) $1.00 a pound.  It was scrapped by a company that went out of  business. 
 It has one ding on it from when it was pitched off a truck, I  assume.  
Probably the best deal I've ever gotten!
 
Well, as for what to do with the information, just chalk it up to  
experience!  After measuring a few dozen coils one begins to make  judgements about 
the "quality" of a coil.
 
I recently bought a receiver on Ebay which I recognized as the one  
described in February 1961 QST, "The BC-453 as a Tunable I. F. in a Multiband  
Receiver."  The coils in the front end were scramble wound on 1/4 inch  forms -- 
for 80 meters: 60 turns no. 36 enameled wire wound within a length  of 1/8 
inch.  The Q of one of these coils was only  about 16.  That's not very 
good, especially compared to the HBR coils  up around 180 or so.  (Its been a 
while so maybe this isn't quite  right.)  Maybe a Q of 80 would be OK for this 
(BC-453) receiver (my  opinion, of course).  I tried different winding 
techniques like solenoid  and layer winding.  Scramble winding gave the lowest Q 
of any I  tried.  That article was very weak in the coil design.  There 
needed  to be a lot more room devoted to the front end so that larger forms 
could be  used to get higher Q.  Yes, I did try different slugs to try to raise 
the Q  with little if any improvement.
 
I find the Q-Meter handy for checking inductance so that the coils are  
pretty close to begin with.  That's when you don't have any detailed  
instructions to start with.  For example, when you want to use different  diameter 
forms on the HBR.  I like to use calculations for tuned circuits,  then use 
the Q-Meter to verify.
 
Happy New Year to everyone on the HBR group.  Keep up the good  work.  
Maybe I'll get around to building an HBR this year.  I have  been collecting 
parts for quite a while.  It just hasn't come to the top of  the list yet.
 
73,
 
Dan K9WEK
 
 
 
checked some coils for the all band command receiver article  written  up 
in QST 
 
 
In a message dated 12/31/2013 12:58:28 P.M. Eastern Standard Time,  
w2dgb at ptd.net writes:

Hi  Dan,

A pleasure to make your acquaintance, and to receive your  interesting 0.02 
worth.

I do have a Heath Q meter, along with the  calibration coil, and have used 
it 
in the past for various inductance  measurements.  And out in the barn I 
have 
a Boonton Q meter, model  number unknown right now, but it is a heavy beast 
and would need work to  make it useable.  So for now it stays there.

Re the Krylon, I  somewhere got the message that it was OK to use.  My 
thanks 
for  confirming that.  I never liked using Ted's idea of Duco cement...And 
I  
have the clear forms that were in the original specs for the #5 HBR that I  
am working on right now.  Never liked them either...they are much too  
fragile.  But over time I have learned a few tricks on how to handle  them, 
so they will work.

Dan, out of curiosity, if I measure the  coil, what do I do with the 
information?  A visual will, or should,  tell me if there are any mistakes, 
and without some frame of reference (In  Ted's literature, perhaps?) I 
wonder 
what the Q value will tell me.   Forgive my lack of knowledge here...my ham 
background is mostly self  taught, with life sciences my training.

The HBR receiver and its story  is a phenomenon for sure.  I was taken with 
it from day one, and am  not surprised that a cult has grown up around the 
radio.

73, Dan,  and Happy New Year,

Bill  W2DGB



----- Original  Message ----- 
From: <Hopperdhh at aol.com>
To:  <hbr at mailman.qth.net>
Sent: Tuesday, December 31, 2013 8:42  AM
Subject: Re: [HBR] WTB coil forms


>
> Hi  Bill,
>
> I know this was addressed to Breck, but I'd like to  throw in my $.02.
>
> I have a Boonton 260-A Q-Meter and have  measured coils before and after
> spraying with a pretty heavy coat of  Clear Krylon and could measure no
> difference.  This was on coils  with Q of about 200, so I'd say its fine 
to 
> use.
> It has very  little solids, so it take quite a heavy coat to  leave much
>  behind.  In my case it was on paper/cardboard formers, and  it held  the 
> wire
> nicely as well as added some strength to the  formers.  It  also dries 
> quickly
> which is  nice.
>
> Its always a good idea to measure the Q of any coil you  wind.  A  Q-Meter
> is a great piece of test  gear.
>
> Dan K9WEK
>
>
>
> In a message  dated 12/30/2013 8:03:30 P.M. Eastern Standard Time,
> w2dgb at ptd.net  writes:
>
> Breck,
>
> Many thanks for re-presenting  your section on winding  HBR coils.  There 
> is
>  a
> wealth of information here and it will  certainly make life  easier for
> those
> contemplating taking on the   project.  I know that I have number of HBR
> coils
> to wind,  and I have  been putting it off.  Reading this material again,  
as
> upgraded, has  given me a bit of a push.
>
> One  question:  With time the turns  sometimes loosen as the Cu  wire
> stretches
> and expands and contracts.   I have  been wondering what you recommend to
> keep
> the turns in place  after  winding.  I know Crosby used Duco or some such
> cement  in ribbons down  the coil windings, but I am considering giving  
the
> whole coil a spritz of  Krylon Clear.   Thoughts?
>
> Happy New Year, Breck, and thanks   again.
>
> 73,  Bill   W2DGB
>
>  ______________________________________________________________
> HBR  mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
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>
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> Please help support this email list:  http://www.qsl.net/donate.html
>  


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From wrcromwell at gmail.com  Wed Jan  1 09:56:05 2014
From: wrcromwell at gmail.com (Bill Cromwell)
Date: Wed, 01 Jan 2014 09:56:05 -0500
Subject: [HBR] HBR parts for swap
In-Reply-To: <FE1853E8164643C0960D65068228F75C@w0eaj>
References: <02a601cf0699$70409f80$50c1de80$@net> <52C37FCF.4080906@gmail.com>
	<FE1853E8164643C0960D65068228F75C@w0eaj>
Message-ID: <52C42C85.8000000@gmail.com>

On 01/01/2014 12:47 AM, TC Dailey wrote:
> Bill C.
>
> I have a BRAND NEW National ACN dial, NIB... original box, original dial
> $30 plus post
>
> Tom - W?EAJ - Denver
Hi Tom,

It's Lorne, VE7BOX that wants the National ACN dial for his project. 
Hopefully he is following his thread and will contact you. I only got on 
the thread to see if I can helps with some of the tubes he wants.

73,

Bill  KU8H


From smithab11 at comcast.net  Wed Jan  1 10:50:16 2014
From: smithab11 at comcast.net (B. Smith)
Date: Wed, 01 Jan 2014 10:50:16 -0500
Subject: [HBR] WTB coil forms
In-Reply-To: <53cb2.71064597.3ff57c15@aol.com>
References: <53cb2.71064597.3ff57c15@aol.com>
Message-ID: <52C43938.7060304@comcast.net>

FYI, the Boonton Inductor  Q Standards Type 103A xx  , the round 
cyclinder with banana plugs on the end can be used on the Heathkit Q 
meter, plugs right in. You can often find these standards by Hanzing 
through those card board boxes under the tables at the hamfests.
Happy New Year
k4che

On 1/1/2014 9:11 AM, Hopperdhh at aol.com wrote:
> Hi Bill,
>   
> I found my Boonton Q-Meter in a local scrap yard, and bought it for (I
> think) $1.00 a pound.  It was scrapped by a company that went out of  business.
>   It has one ding on it from when it was pitched off a truck, I  assume.
> Probably the best deal I've ever gotten!
>


From daileyservices at qwest.net  Wed Jan  1 10:51:46 2014
From: daileyservices at qwest.net (TC Dailey)
Date: Wed, 1 Jan 2014 08:51:46 -0700
Subject: [HBR] National ACN dial
References: <02a601cf0699$70409f80$50c1de80$@net>
	<52C37FCF.4080906@gmail.com><FE1853E8164643C0960D65068228F75C@w0eaj>
	<52C42C85.8000000@gmail.com>
Message-ID: <9D7F9B15CD884DEEA61389C1283ADBF8@w0eaj>

Sorry gang, the dial is sold

Tom

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From bear57 at telus.net  Wed Jan  1 13:11:57 2014
From: bear57 at telus.net (Lorne Barber)
Date: Wed, 1 Jan 2014 10:11:57 -0800
Subject: [HBR] HBR parts for swap
In-Reply-To: <52C42C85.8000000@gmail.com>
References: <02a601cf0699$70409f80$50c1de80$@net>
	<52C37FCF.4080906@gmail.com>	<FE1853E8164643C0960D65068228F75C@w0eaj>
	<52C42C85.8000000@gmail.com>
Message-ID: <02c101cf071c$f5e5cab0$e1b16010$@net>

Thanks for the offer Bill. I will get back to you tomorrow after I have
searched the junque box.
Happy New Year.
7 3 
Lorne
Ve7box


-----Original Message-----
From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
Behalf Of Bill Cromwell
Sent: January-01-14 6:56 AM
To: HBR Receiver List
Subject: Re: [HBR] HBR parts for swap

On 01/01/2014 12:47 AM, TC Dailey wrote:
> Bill C.
>
> I have a BRAND NEW National ACN dial, NIB... original box, original 
> dial
> $30 plus post
>
> Tom - W?EAJ - Denver
Hi Tom,

It's Lorne, VE7BOX that wants the National ACN dial for his project. 
Hopefully he is following his thread and will contact you. I only got on the
thread to see if I can helps with some of the tubes he wants.

73,

Bill  KU8H

______________________________________________________________
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From glwells at yahoo.com  Wed Jan  1 19:25:54 2014
From: glwells at yahoo.com (Gary Wells)
Date: Wed, 1 Jan 2014 16:25:54 -0800 (PST)
Subject: [HBR] WTB coil forms
In-Reply-To: <52C19C60.3070003@comcast.net>
References: <8D0D390B96D4B47-2768-55C60@webmail-d253.sysops.aol.com>
	<52C19C60.3070003@comcast.net>
Message-ID: <1388622354.9008.YahooMailNeo@web141705.mail.bf1.yahoo.com>

Chuck and all, this article is outstanding and really gives me confidence to try my luck at some coil winding for my HBR-13C. I am hoping to get back into it and expand it to other bands. I see you are in Palm Coast, I am in Sarasota. Perhaps one day we can compare notes and get our receivers really rocking. Team work! My 13C has an Eddystone as well and I will be redoing the front panel to a thicker material and changing the S meter.?

73's
Gary
WB9AYD


________________________________
 From: B. Smith <smithab11 at comcast.net>
To: hbr at mailman.qth.net 
Sent: Monday, December 30, 2013 11:16 AM
Subject: Re: [HBR] WTB coil forms
 

A discussion of various alternate coil forms can be found:
http://k4che.com/HBR/RF%20Mixer%20Osc%20Band%20Coils%20Page%201.htm

On 12/30/2013 11:10 AM, cemilton at aol.com wrote:
> GM to the list and HAPPY NEW YEAR TO ALL.
>
> I'm new to this reflector but have spent some time in the archives "catching up" on tales of the HBR.
>
> I recently acquired an HBR-16 with one set of coils for 40m.? This particular set was built w/o an on-board power supply and doesn't have a calibrator. (I'll be using an external supply and will add the calibrator circuit later)
>
> The chassis is a work of art and I didn't have the heart to cannibalize the rig and start from the beginning.? So, I've re-worked the existing chassis and made component upgrades where needed.? At this juncture, the rig is working nicely on 40m.? I still have a new front panel to fabricate for the Eddystone dial and an S-meter.
>
> I'd like to add at least 80m and 20m (in that order) but alas, no coil forms.? At least not the American Phenolic 24-5p originals.? I'm guessing these are pretty much un-obtainable but I need to ask.?  If anyone has any, even one, I'd be interested in purchasing them.? I have the APC caps so I only need serviceable coil forms.
>
> I'm aware of the use of PVC and even pill bottles so I know there is an "out" if I cannot find some originals.
>
> I do have a question of the group.? I have four BUD forms, the ribbed type with 5 pins.? And they measure the requisite 1.25" diameter.? However, I'm not sure just how well these work when compared to the 24-5p ones.? I used the microwave oven for 5 seconds to see if they heated up.? Well, not as much as some older 1920's forms but more than the clear plastic.? So, I'd expect a somewhat higher Q with the clear ones versus any others.? Am I off-base on this??? I'd sure appreciate any comments.? If anyone has experience with the BUD ribbed forms in an HBR please let me know your thoughts/experiences.
>
> Thanks, All, for the BW and for reading this over.
>
> Best to all in the New Year.
>
> 73
> Chuck
> W4MIL
> Palm Coast, FL
>
>
>
>? ? 
> ????? ????
>? 
>
>
>? 
> ______________________________________________________________
> HBR mailing list
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From Hopperdhh at aol.com  Thu Jan  2 06:49:21 2014
From: Hopperdhh at aol.com (Hopperdhh at aol.com)
Date: Thu, 2 Jan 2014 06:49:21 -0500 (EST)
Subject: [HBR] WTB coil forms
Message-ID: <7caf6.59d2df67.3ff6ac40@aol.com>



Thanks for the tip.  I bought the Q-Meter about 15 years ago, and  since 
then I have found one Boonton standard coil.  My Q-Meter checked out  pretty 
close, so I didn't attempt to calibrate it.  I usually only care  about 
relative readings anyway.  I also have spare detector assembly for it  -- 
somewhere around here!
 
Dan K9WEK
 
 
 
In a message dated 1/1/2014 2:28:38 P.M. Eastern Standard Time,  
smithab11 at comcast.net writes:

FYI, the  Boonton Inductor  Q Standards Type 103A xx  , the round  
cyclinder with banana plugs on the end can be used on the Heathkit Q  
meter, plugs right in. You can often find these standards by Hanzing  
through those card board boxes under the tables at the hamfests.
Happy  New Year
k4che

On 1/1/2014 9:11 AM, Hopperdhh at aol.com wrote:
>  Hi Bill,
>   
> I found my Boonton Q-Meter in a local  scrap yard, and bought it for (I
> think) $1.00 a pound.  It was  scrapped by a company that went out of  
business.
>   It  has one ding on it from when it was pitched off a truck, I   assume.
> Probably the best deal I've ever  gotten!
>

______________________________________________________________
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From w0ep at w0ep.us  Sat Jan  4 11:29:51 2014
From: w0ep at w0ep.us (w0ep at w0ep.us)
Date: Sat, 04 Jan 2014 09:29:51 -0700
Subject: [HBR] HBR - BFO progress
Message-ID: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>


From Gcromer at usit.net  Sat Jan  4 13:20:12 2014
From: Gcromer at usit.net (Gerald Cromer)
Date: Sat, 4 Jan 2014 13:20:12 -0500
Subject: [HBR] HBR - BFO progress
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>
Message-ID: <BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>

No message on the last posting.

Gerald K4NHN
Cayce, SC


----- Original Message ----- 
From: <w0ep at w0ep.us>
To: <hbr at mailman.qth.net>
Sent: Saturday, January 04, 2014 11:29 AM
Subject: [HBR] HBR - BFO progress


> 
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
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> 
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From w0ep at w0ep.us  Sat Jan  4 20:38:04 2014
From: w0ep at w0ep.us (w0ep at w0ep.us)
Date: Sat, 04 Jan 2014 18:38:04 -0700
Subject: [HBR] HBR - BFO progress
Message-ID: <20140104183804.c047917b6272adbdbe8692f8c22b6543.fe9dcd6b3c.wbe@email09.secureserver.net>



I think I'm finally off the ground with the HBR project, at least a
little, tiny bit.


I took one of these coil-cans that I have in my parts box and took it
apart.
It wasn't going to do the job as it was, so I stripped out the coil and
the
other parts.


Using various web pages for reference, I figured out that I needed
somewhere
around 8000-9000 microHenries of inductance in order to have a 50 pF
variable
capacitor swing the BFO between 83 and 86 kHz  (I'm using the 85 kHz IF
cans).


I wrapped 10 turns on the coil form and figured what I thought was the
right AL number by measuring the inductance with this little digital
meter
I've got.  And that led me to conclude that I needed about 800 turns on
my coil.
Also, the web again provided the info that I wanted my coil tap to
be at around 25% up from the grounded end of the BFO coil for a
Hartley oscillator.


With all of that info, I wound 200 turns then put a loop,then 400 turns
and another loop and then the final 200 turns.
The coil form has four "legs" where connections solder in
and have the two end and the two loops soldered in.


I did a mock-up of the HBR-13 vfo using a 7-pin socket, some PC board
and a 6BH6.  I used junkbox parts for the capacitors and resistors,
tried
to be close to the schematic values.  I terminated the output (pin 5)
with a small trimmer cap followed by a 26 kOhm resistor  (I didn't
have a 22k).


I had a small tragedy when I found that my regular O-scope was
acting up and won't start.  More work to do there!  But I found an
old scope in the garage that sort-of works.  


I have a Heathkit IP-17 power supply which worked for filament
and B+ with alligator clip leads to my circuit board.


And, I had a waveform!  The frequency counter helped me trim
the inductor core to achieve 85 kHz at center setting of my air-variable
50 pF BFO control capacitor.


It turned out that my scramble-wound coil was not able to get
to 8k microHenries, more like 6k.  That meant adding more
capacitance to get things at the frequency I want, and the 50 pF
only gives me a swing of a bit more than 1 kHz both sides of 85.
I may make another run at that if you all think I need more swing than
that.


The only other objectionable thing was that the negative peaks
on my waveform are a bit truncated.  It looks like I am hitting a
voltage
supply rail in that direction, or something.  I may fool around with
that
a bit.  Does the BFO need a nice waveform?


I'm really tickled that I was able to make this work at all.  I'm going
to
watch at our hamfest later this month for a better 50pF trimmer cap, and
I have my
tube list.  I need to make a more complete parts lists, that's a fact. 
There
are probably some potentiometers that I could pick up.




Chris Howard
w0ep
Columbus, MS

From waltah at earthlink.net  Sat Jan  4 23:15:44 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Sat, 4 Jan 2014 23:15:44 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <20140104183804.c047917b6272adbdbe8692f8c22b6543.fe9dcd6b3c.wbe@email09.secureserver.net>
References: <20140104183804.c047917b6272adbdbe8692f8c22b6543.fe9dcd6b3c.wbe@email09.secureserver.net>
Message-ID: <652335357.20140104231544@earthlink.net>

Chris said:

> It turned out that my scramble-wound coil was not able to get
> to 8k microHenries, more like 6k.  That meant adding more
> capacitance to get things at the frequency I want, and the 50 pF
> only gives me a swing of a bit more than 1 kHz both sides of 85.
> I may make another run at that if you all think I need more swing than
> that.

If you plan to receive only CW (and AM) and beat notes not much over 1
kc are high enough that might be enough. If you're going to receive
SSB as well then you'll want to park the center of the IF bandpass on
roughly the center of the sideband which would likely be a little
higher than that -- 1.5 kcs? -- and put the BFO where the carrier
should be. By the time you allow adjusting a couple hundred cps one
way or the other to get a more natural sounding voice AND a bit of
drift in the BFO so the frequency range isn't exactly according to
plan it's probably good to have a total swing of 4 kcs or even 5 kcs.

You'll also (probably) have to tweak the center frequency via your
fixed shunt cap to get lined up properly with those nominal 85 kcs
IFTs. The command set ones seem to me to often be off 1 kc or so one
way or the other, and they don't have very much tuning range with
those itty-bitty trimmers.

Because of this it's best to get three xfmrs from one command set AND
use the BFO assembly from that set.  Mismatches can be worked out, but
it's a tedious job.

My hat's off to anyone who has wound a 800-turn oscillator coil!

> The only other objectionable thing was that the negative peaks on my
> waveform are a bit truncated. It looks like I am hitting a voltage
> supply rail in that direction, or something. I may fool around with
> that a bit. Does the BFO need a nice waveform?

ALL ordinary oscillator circuits operate class 'C', that is, the
current in the tube (and energy input to the tank circuit) is in
pulses. The higher the Q of the tank circuit the better the voltage
waveform across it will look, although it will look better across the
whole tank than from cathode to ground, anyway.

(High quality signal generators and the like are sometimes class 'A'
but they require some sort of AGC circuit to keep them oscillating
without going class 'C'.)

Waveform matters because anything but a pure sine wave contains
harmonics, and these can often go up into the lower ham bands. The
first issue is the 1st IF which should be planted close to halfway
between harmonics of the MEASURED 2nd IF, unless you are using IFTs
with enough tuning range to trim things post-construction. The command
set IFTs do not have that much range.

For example if the 2nd IF is exactly 85 kcs then 20x = 1700 kcs; you
would want to go either ~40 kcs higher or ~40 kcs lower with the 1st
IF. If you're using a crystal controlled 2nd oscillator with command
set IFTs some breadboarding may be needed to figure this out.

However commercial 85 or 100 kcs IFTs have a wider tuning range; with
them you can probably just trim the 2nd IF (and BFO)
post-construction. However you STILL don't want BFO energy getting
into your IFs because it can cause overload and birdies with signals
that ought to be out of passband, also it may mess up the AGC action.

These issues are one disadvantage of double-conversion designs.

IF your are following a W6TC design closely much of the following will
already be done for you.

Since the BFO waveform cannot really be great, treat it like any other
oscillator you don't want interference from. Put it as far from the
input to the 1st IF/2nd mixer area as possible. Usually that means on
the far side of the product detector from the IF strip. Often it will
work out well in or near a front corner of the chassis, making you
good to go with a short lead to the BFO tuning cap. Keep all the BFO
parts close together.

Keep leads short and use shielded wire for the really (RF) hot ones
like the hot end of the coil to the tuning cap unless you can get
them down to the 1" range.

Think about filament wiring too: It's a good way for stray signals to
get around a chassis. Sometimes a 12V twin triode with 12V filament
supply and the 'cold' filament half serving as the BFO, a bypass on
the filament tap, and the 'hot' filament half of the tube as 1st audio
works out well -- the audio tube filament serves as a filter resistor
for the BFO filament.

Decouple the B+ carefully. Do the math for decoupling at 85kcs: .01
mfd caps WILL NOT do the job. The command sets used 0.05's and that's
really the minimum. The BFO switch must switch an (RF) cold lead -- if
switching the B+ then decouple at the BFO location.

Try to confine ALL the 85 kcs energy to that little area. Think about
how you'd add a below-chassis shield if needed -- only sometimes
necessary.

Use a single ground point for the whole BFO stage and especially do
not let tank circuit currents flow in the chassis, for example, by
grounding the coil at one place and the fixed cap somewhere else. If
the tuning cap is small and on the panel close to the coil and main
fixed cap, that (small) current is probably okay if the 1st IF and
mixer are on the far side -- for example, toward the rear of the
chassis.

This may seem over obsessive but I've redesigned from scratch as often
because the BFO was getting into Bad Places as for all other failings
together.

Again, if you follow W6TC closely, you will not have to worry about
these things. But the minute you start rearranging, they become
important.

> I'm really tickled that I was able to make this work at all. I'm
> going to watch at our hamfest later this month for a better 50pF
> trimmer cap, and I have my tube list. I need to make a more complete
> parts lists, that's a fact. There are probably some potentiometers
> that I could pick up.

It's always a kick when an oscillator actually does. :-)

Finally, those who do want to strike out in another direction (from
the W6TC designs) will find that the Heath HR-10 ham band receiver has
just about everything except the coils, coil sockets, and front
panel/cabinet. (The HR-10 front panel isn't tall enough to allow for
the coils above the chassis.) Most of the chassis work is already done
-- you have to add the coil socket holes, and 3-4 more for tubes.
(Mine came out with 10 tubes, mostly double section.) A flat shield
plate must be added above the chassis between the RF and mixer coils.
There's plenty of room on this chassis. I added a 100 kcs calibrator
and there's still ample room.

There's a built in power supply but a separate speaker is required.

The string drive dial is about the second best thing to an Eddystone
898; I found it entirely satisfactory. Your coils can be tracked to
the original dial calibration which is silk-screened on the back of a
sheet of Lucite; of course you use the original tuning cap.

This set uses a half-lattice (two) crystal filter at 1682 kcs and you
have two IF stages (and BFO) at that frequency -- no second conversion
is needed.

Going this route you ditch a whole lot of parts-finding but add the
thrill and frustration of doing your own design. I think there's a
blow-by-blow from from when I did this, in the list archives.

Walt Hutchens


From smithab11 at comcast.net  Sun Jan  5 11:36:22 2014
From: smithab11 at comcast.net (B. Smith)
Date: Sun, 05 Jan 2014 11:36:22 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>
	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
Message-ID: <52C98A06.80501@comcast.net>

I highly recommend that the builder do the BFO first. You will get your 
feet wet and solve a major problem with construction.  My best luck has 
been with a colpits oscillator but others were tried See:
(http://k4che.com/HBR/BFO%20Coil%20Page%201and%20photos/BFO%20Coil%20Page%20%201.htm)
k4che

From imalowfer at yahoo.com  Sun Jan  5 14:06:08 2014
From: imalowfer at yahoo.com (Ron Barlow)
Date: Sun, 5 Jan 2014 11:06:08 -0800 (PST)
Subject: [HBR] HBR - BFO progress
In-Reply-To: <52C98A06.80501@comcast.net>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
	<52C98A06.80501@comcast.net>
Message-ID: <1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>

Hi Breck,
?
?Thanks for your posting!
?
?I see a problem with the suggested Colpitts circuit, that you provided a?link to. If I understand the labeling on the schematic diagram correctly, there is a .01 mfd capacitor, on each end of the RFC. The cap on the left side of the choke, is electrically in shunt with the 180 pf cap, that comprises part of the oscillator tank circuit. 
This will profoundly alter the feedback ratio, and the resonant freq of the tank ckt.
?In fact, the feedback ratio will be altered to the point that?I?seriously doubt that the circuit will oscillate at all.
?
?I believe that the .01 cap on the left side of the choke should be removed.
???????????? 
??????? 73 de Ron?? n4gjv


________________________________
From: B. Smith <smithab11 at comcast.net>
To: HBR Receiver List <hbr at mailman.qth.net> 
Sent: Sunday, January 5, 2014 11:36 AM
Subject: Re: [HBR] HBR - BFO progress


I highly recommend that the builder do the BFO first. You will get your 
feet wet and solve a major problem with construction.? My best luck has 
been with a colpits oscillator but others were tried See:
(http://k4che.com/HBR/BFO%20Coil%20Page%201and%20photos/BFO%20Coil%20Page%20%201.htm)
k4che
______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:HBR at mailman.qth.net

This list hosted by: http://www.qsl.net/
Please help support this email list: http://www.qsl.net/donate.html

From waltah at earthlink.net  Sun Jan  5 17:13:39 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Sun, 5 Jan 2014 17:13:39 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>
	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
	<52C98A06.80501@comcast.net>
	<1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
Message-ID: <1012674566.20140105171339@earthlink.net>

Ron said:

> ?I see a problem with the suggested Colpitts circuit, that you
> provided a?link to. If I understand the labeling on the schematic
> diagram correctly, there is a .01 mfd capacitor, on each end of the
> RFC. The cap on the left side of the choke, is electrically in shunt
> with the 180 pf cap, that comprises part of the oscillator tank
> circuit. This will profoundly alter the feedback ratio, and the
> resonant freq of the tank ckt. ?In fact, the feedback ratio will be
> altered to the point that?I seriously doubt that the circuit will
> oscillate at all.

That's a problematic circuit either way. Without the 0.01 mfd cap it
will oscillate at roughly the frequency set by the tank circuit but
the choke is in shunt with the 180 mmf capacitor. You really don't
want a choke in a VFO circuit: They are terribly unstable.

I've never had any trouble as simple as getting the tap right for a
Hartley. The turns ratio is the same as the proper one for the caps in
a Colpitts circuit. If I remember correctly the command sets use a
separate winding for feedback in that BFO; that's another way to do it
and the turns ratio is the same as the ratio appropriate for a Hartley
or Colpitts circuit.

You can get rid of the choke in a Colpitts circuit by using a resistor
instead and for the very highest Q (hi-Q helps with stability against
tube gain variations due to structural and voltage fluctuations ...)
tap the coil APPROXIMATELY at zero RF voltage, letting the capacitors
set the exact feedback ratio and/or tuning range.

As long as the voltage across the resistor is just a small fraction of
the total the effect on circuit Q will be unimportant.

Feedback ratios really aren't supercritical. The amplitude of
oscillation in a class 'C' oscillator is set by the load imposed when
the grid is driven positive over a fairly wide range of ratios. (The
grid is then basically a shunt diode that eats the excess energy.)
Only if there isn't enough feedback or it becomes so great that the
tube goes into blocking oscillations will there be trouble.

(Blocking: the grid capacitor charges so much during the positive
swing that when the tank circuit swings the grid negative the tube
cannot conduct again even on the next positive swing of the tank.
Instead the capacitor must discharge through the grid leak resistor
for several or many cycles of the RF before the tube again conducts.
This is a good thing for a superregenerative detector, not so good for
a BFO, LO, etc. Cure involves some combination of less feedback, lower
grid leak resistor, and smaller grid coupling cap.)

Well ... long leads and/or the latest UHF-capable tube types can get
you VHF parasitics if you don't take precautions and these parasitics
may occur over just a part of a cycle of the intended oscillation
frequency. But once you've seen this you'll recognize it. Horrific
crashing noise when you tune the oscillator is one symptom because
there's very high VHF current in the capacitor bearings or contacts.

Nearly all construction project articles have clear enough directions
to get you past such issues. It's best to NOT substitute 'better'
tubes than those specified. 6SK7 replaced by a 6BZ6? GOOD chance of
VHF parasitics there, unless you use countermeasures.

This is true throughout the RF-IF stages of a receiver. Also in such
stages 'hotter' tubes routinely need a cross-socket shield to separate
input from output.

The latest tube types will require extra work compared to those of the
50's and if the project you're doing is from a 50's magazine article
the how-to for dealing with the later tubes won't be in the article or
circuit. This can be about the most challenging troubleshooting you'll
see.

All resistors in an oscillator should be the modern carbon film ones:
They're more stable in every respect than the vintage ones. AVOID
bypass-type disk ceramics in an oscillator, even for bypass jobs: They
are NOT stable, indeed their capacitance may vary with the voltage
across them as well as temperature.

Mica bypasses work well in oscillators, even the larger 'postage
stamp' micas.

You're looking for a few parts per million stability, right? Receiver
oscillators are precision instruments: You can breadboard them with
'whatever' parts but use only the best for the actual build.

Walt Hutchens
KJ4KV


From smithab11 at comcast.net  Sun Jan  5 18:23:06 2014
From: smithab11 at comcast.net (B. Smith)
Date: Sun, 05 Jan 2014 18:23:06 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <1012674566.20140105171339@earthlink.net>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>	<52C98A06.80501@comcast.net>	<1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
	<1012674566.20140105171339@earthlink.net>
Message-ID: <52C9E95A.1040406@comcast.net>

I would like to post these comments on the BFO page. I guess I use a lot 
of RF chokes, ferrite beads are also some of my favorite decoupling devices.
I've had a lot of fun with the receiver works great. Now working on home 
brew IF coils.
I  recommend the HBR project to anyone. But start off simple.
Bread board that BFO before building it.  :-)
k4che

On 1/5/2014 5:13 PM, Walt Hutchens wrote:
> Ron said:
>
>>   I see a problem with the suggested Colpitts circuit, that you
>> provided a link to. If I understand the labeling on the schematic
>> diagram correctly, there is a .01 mfd capacitor, on each end of the
>> RFC. The cap on the left side of the choke, is electrically in shunt
>> with the 180 pf cap, that comprises part of the oscillator tank
>> circuit. This will profoundly alter the feedback ratio, and the
>> resonant freq of the tank ckt.  In fact, the feedback ratio will be
>> altered to the point that I seriously doubt that the circuit will
>> oscillate at all.
> That's a problematic circuit either way. Without the 0.01 mfd cap it
> will oscillate at roughly the frequency set by the tank circuit but
> the choke is in shunt with the 180 mmf capacitor. You really don't
> want a choke in a VFO circuit: They are terribly unstable.
>
> I've never had any trouble as simple as getting the tap right for a
> Hartley. The turns ratio is the same as the proper one for the caps in
> a Colpitts circuit. If I remember correctly the command sets use a
> separate winding for feedback in that BFO; that's another way to do it
> and the turns ratio is the same as the ratio appropriate for a Hartley
> or Colpitts circuit.
>
> You can get rid of the choke in a Colpitts circuit by using a resistor
> instead and for the very highest Q (hi-Q helps with stability against
> tube gain variations due to structural and voltage fluctuations ...)
> tap the coil APPROXIMATELY at zero RF voltage, letting the capacitors
> set the exact feedback ratio and/or tuning range.
>
> As long as the voltage across the resistor is just a small fraction of
> the total the effect on circuit Q will be unimportant.
>
> Feedback ratios really aren't supercritical. The amplitude of
> oscillation in a class 'C' oscillator is set by the load imposed when
> the grid is driven positive over a fairly wide range of ratios. (The
> grid is then basically a shunt diode that eats the excess energy.)
> Only if there isn't enough feedback or it becomes so great that the
> tube goes into blocking oscillations will there be trouble.
>
> (Blocking: the grid capacitor charges so much during the positive
> swing that when the tank circuit swings the grid negative the tube
> cannot conduct again even on the next positive swing of the tank.
> Instead the capacitor must discharge through the grid leak resistor
> for several or many cycles of the RF before the tube again conducts.
> This is a good thing for a superregenerative detector, not so good for
> a BFO, LO, etc. Cure involves some combination of less feedback, lower
> grid leak resistor, and smaller grid coupling cap.)
>
> Well ... long leads and/or the latest UHF-capable tube types can get
> you VHF parasitics if you don't take precautions and these parasitics
> may occur over just a part of a cycle of the intended oscillation
> frequency. But once you've seen this you'll recognize it. Horrific
> crashing noise when you tune the oscillator is one symptom because
> there's very high VHF current in the capacitor bearings or contacts.
>
> Nearly all construction project articles have clear enough directions
> to get you past such issues. It's best to NOT substitute 'better'
> tubes than those specified. 6SK7 replaced by a 6BZ6? GOOD chance of
> VHF parasitics there, unless you use countermeasures.
>
> This is true throughout the RF-IF stages of a receiver. Also in such
> stages 'hotter' tubes routinely need a cross-socket shield to separate
> input from output.
>
> The latest tube types will require extra work compared to those of the
> 50's and if the project you're doing is from a 50's magazine article
> the how-to for dealing with the later tubes won't be in the article or
> circuit. This can be about the most challenging troubleshooting you'll
> see.
>
> All resistors in an oscillator should be the modern carbon film ones:
> They're more stable in every respect than the vintage ones. AVOID
> bypass-type disk ceramics in an oscillator, even for bypass jobs: They
> are NOT stable, indeed their capacitance may vary with the voltage
> across them as well as temperature.
>
> Mica bypasses work well in oscillators, even the larger 'postage
> stamp' micas.
>
> You're looking for a few parts per million stability, right? Receiver
> oscillators are precision instruments: You can breadboard them with
> 'whatever' parts but use only the best for the actual build.
>
> Walt Hutchens
> KJ4KV
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


From waltah at earthlink.net  Sun Jan  5 19:51:48 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Sun, 5 Jan 2014 19:51:48 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <52C9E95A.1040406@comcast.net>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>
	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
	<52C98A06.80501@comcast.net>
	<1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
	<1012674566.20140105171339@earthlink.net>
	<52C9E95A.1040406@comcast.net>
Message-ID: <1109192731.20140105195148@earthlink.net>

B. Smith said:

> I would like to post these comments on the BFO page.

Anything I post can be used in any way anyone wants.

> I guess I use a lot of RF chokes, ferrite beads are also some of my
> favorite decoupling devices.

Modern 'vintage' builders are hurt by the fact that the common
oscillator circuits were developed and popularized when standards of
stability were much lower than those needed for SSB. So the references
on those circuits too are mostly older and don't include the
considerations needed for precision tunable oscillators. Good stuff is
out there but it isn't found in the most common vintage sources.

If you want to receive SSB on 80M that's 50 cps or so at 4 mcs: 12
ppm. You can hardly buy a nominally zero temperature coefficient cap
that's much better than 50 ppm/degree/F. A 2.5mH choke will be MUCH,
MUCH worse. Plus of course gradual drift due to changes in the varnish
and moisture effects.

The first line of defense is eliminating (so far as possible) reactive
components. In other words, you want the tank circuit to be the tank
circuit AND NOTHING ELSE SHOULD BE IN THAT GAME. Other inductors and
capacitors should be eliminated.

There are some surprises in doing this. The cathode-to-filament
junction (inside the cathode sleeve) is an unstable capacitor (the
filament wires squirm in there) shunted by a poor quality diode. This
makes the circuits with an RF-hot cathode problematic. Ground the
cathode if possible.

(And the damn diode may cause hum modulation if the filament is AC.
This doesn't matter at a Mc or less but on the higher bands it can be
limiting unless designed around. Bias the filament positive or put the
cathode at RF ground.)

Try to feed the DC at points of zero RF voltage and use a resistor to
decouple. I like the Colpitts circuit with a tapped inductor for plate
voltage coupling. You let the coil tap float for RF.

This is easier to get working than it sounds: Wind the first coil,
hook up the plate voltage through a resistor to the plate of the tube,
and check it out. Then touch the coil with a pencil point looking for
the point at which there's no effect on frequency -- suitable HV
precautions required when doing this. Rewind the coil -- I never get
them right the first time anyway -- with a tap at the zero effect
point and connect the plate resistor there.

You now have an oscillator for which -- pretty much -- the parts that
you think are the tank circuit ARE the tank circuit. Focus on
stability of those parts and you'll have a stable oscillator.

One part that you might not think of as part of the tank is the tube
itself. Transit time and gain limits cause some phase shift and
because the loop phase shift must be exactly 360 degrees for
oscillation, any change in the effects from the tube will shift the
frequency.

(Suppose the tube phase shift INCREASES by 5 degrees due to a plate
voltage change. Then the frequency must change so that the tank
circuit phase shift DECREASES by 5 degrees to maintain the 360 degree
condition.)

This can be reduced with higher gain and UHF-design tubes but those
bring their own problems.

Another approach is to decouple the tube as much as possible and there
are several 'high stability' oscillator circuits (Clapp, Vackar ...)
that do this. THESE CIRCUITS ONLY HELP WITH TUBE-RELATED FREQUENCY
CHANGES. A 'drifty' tank circuit will cause just as much drift as for
any other circuit.

Usually the practical answer is to use a fairly conventional circuit,
minimize the number of parts with RF on them and then stabilize those
parts.

When stabilizing, look at the big picture: In my Eddystone dial HBR I
found that the aluminum chassis bulged upward as it warmed and thus
rotated the tuning cap ever so slightly. This effect was far too
small to be visible, but it led to a couple of kcs drift on 80M. I
took steps to minimize the heating of that part of the chassis but in
future designs I'll change how the cap is mounted so this can't
happen.

(Diagnosis by using a digital thermometer on the chassis and noting
that the frequency changed as it warmed, then gently applying the
corner of an ice cube there and watching it drift rapidly back the
other way ...)

For a BFO at 85kcs SSB stability isn't a big job. But for a local
oscillator on 20 or 10M it will be a very big deal indeed. Even a BFO
at 1700 kcs (as for the Heath HR-10 to HBR project) requires care.

> I've had a lot of fun with the receiver works great. Now working on home
> brew IF coils.
> I  recommend the HBR project to anyone. But start off simple.
> Bread board that BFO before building it.  :-)

Yep. I'd also recommend following an established design for the first
project. Every change from a straight copy will require debugging and
the first time 'round you want as little of that as possible.

Walt Hutchens
KJ4KV


From w0ep at w0ep.us  Sun Jan  5 20:06:41 2014
From: w0ep at w0ep.us (Chris Howard w0ep)
Date: Sun, 05 Jan 2014 19:06:41 -0600
Subject: [HBR] HBR - BFO progress
In-Reply-To: <52C98A06.80501@comcast.net>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
	<52C98A06.80501@comcast.net>
Message-ID: <52CA01A1.8010804@w0ep.us>


Mr Smith, your BFO page and your other HBR pages have been
very helpful to me.  That's what prompted me to get started
with the BFO.

I decided to investigate
the Hartley to see what the inductor tap requirements were.
I figured that the Hartley was an old-time circuit and
if those guys could wind one maybe I could too as long as
I could get the specifications.  I have an inductance/capacitance
meter, an o-scope, frequency counter, generator... I ought
to be able to do it if those guys could :-)

I looked around and found one statement that the Hartley
tap needed to be 1/5th to 1/3rd from the cold end.

The other thing was to go through some inductance/capacitance
combinations on the assumption that the 50 pF BFO control
was enough to move the frequency X amount either way.

I did end up rewinding my coil today.  I take the
tuning slug out and use a long thin machine screw as an
axle.  I wrapped the screw with some blue masking tape
to get it to run in the middle of the coil form; a couple
of washers and a nut put a clamping action from each
end of the coil form.  Then I put
the tail end of the machine screw in a hand drill which
has a little handle bob on the side.  I can mount the drill
horizontal in the bench vice and crank the drill with one
hand while guiding the wire with the other hand.  I upped my
turns count about 10% and the new coil is looking better.

Just for posterity, a coil of about 8k-9k mH with a tap
at 25% up from the cold end is what I was aiming for.
It didn't seem to matter if the cold end went on the
form first or last.

My plan is to get the inductance in the neighborhood, then put
on the right amount of capacitance + 1/2 of the control capacitance
to get things at the desired frequency. I can fiddle with the
tuning slug in the coil to trim things up.

Chris
w0ep


On 1/5/2014 10:36 AM, B. Smith wrote:
> I highly recommend that the builder do the BFO first. You will get your feet wet and solve a major problem with construction.  My best luck has been with a colpits oscillator but others were tried See:
> (http://k4che.com/HBR/BFO%20Coil%20Page%201and%20photos/BFO%20Coil%20Page%20%201.htm)
> k4che
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> 
> 

From smithab11 at comcast.net  Sun Jan  5 20:55:16 2014
From: smithab11 at comcast.net (B. Smith)
Date: Sun, 05 Jan 2014 20:55:16 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <52CA01A1.8010804@w0ep.us>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>	<52C98A06.80501@comcast.net>
	<52CA01A1.8010804@w0ep.us>
Message-ID: <52CA0D04.7050003@comcast.net>

Hi Chris
  Please

On 1/5/2014 8:06 PM, Chris Howard w0ep wrote:
>
> I decided to investigate
> the Hartley to see what the inductor tap requirements were.
> I figured that the Hartley was an old-time circuit and
> if those guys could wind one maybe I could too as long as
> I could get the specifications.  I have an inductance/capacitance
> meter, an o-scope, frequency counter, generator... I ought
> to be able to do it if those guys could :-)
>
> I looked around and found one statement that the Hartley
> tap needed to be 1/5th to 1/3rd from the cold end.The other thing was to go through some inductance/capacitance
> combinations on the assumption that the 50 pF BFO control
> was enough to move the frequency X amount either way.
>
> I did end up rewinding my coil today.  I take the
> tuning slug out and use a long thin machine screw as an
> axle.  I wrapped the screw with some blue masking tape
> to get it to run in the middle of the coil form; a couple
> of washers and a nut put a clamping action from each
> end of the coil form.  Then I put
> the tail end of the machine screw in a hand drill which
> has a little handle bob on the side.  I can mount the drill
> horizontal in the bench vice and crank the drill with one
> hand while guiding the wire with the other hand.  I upped my
> turns count about 10% and the new coil is looking better.
>
> Just for posterity, a coil of about 8k-9k mH with a tap
> at 25% up from the cold end is what I was aiming for.
> It didn't seem to matter if the cold end went on the
> form first or last.
>
> My plan is to get the inductance in the neighborhood, then put
> on the right amount of capacitance + 1/2 of the control capacitance
> to get things at the desired frequency. I can fiddle with the
> tuning slug in the coil to trim things up.
>
> Chris
> w0ep
>
>
> On 1/5/2014 10:36 AM, B. Smith wrote:
>> I highly recommend that the builder do the BFO first. You will get your feet wet and solve a major problem with construction.  My best luck has been with a colpits oscillator but others were tried See:
>> (http://k4che.com/HBR/BFO%20Coil%20Page%201and%20photos/BFO%20Coil%20Page%20%201.htm)
>> k4che
>> ______________________________________________________________
>> HBR mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/hbr
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:HBR at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


From imalowfer at yahoo.com  Sun Jan  5 21:40:29 2014
From: imalowfer at yahoo.com (Ron Barlow)
Date: Sun, 5 Jan 2014 18:40:29 -0800 (PST)
Subject: [HBR] HBR - BFO progress
In-Reply-To: <1012674566.20140105171339@earthlink.net>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>	<52C98A06.80501@comcast.net>	<1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
	<1012674566.20140105171339@earthlink.net>
Message-ID: <1388976029.29767.YahooMailNeo@web160101.mail.bf1.yahoo.com>

Hi Walt,
?
?Your interesting comments, re parasitic oscillations, reminded me of a long ago incident.
?
Some 40?years ago, I constructed an 80m VF0, using a fairly high transconductance 7 pin miniature tube (6BZ6 or 6CB6, I believe). 
?It had a peculiar problem, that happened to occur in ~ the mid portion of the desired freq range. It would "jump over" a particular frequency (~ 3.6 Mhz, IIRC), that?I?was attempting to adjust the vfo to!
?The?vfo would perform fb, at 3.5 Mhz, and it would continue to function fine, as I increased its?frequency, until its frequency approached 3.6 Mhz, then it would "pole vault" over 3.6 Mhz, to ~ 3.61 Mhz. 
?A similar situation occurred when I attempted to adjust the vfo?freq, downward, from above 3.6 Mhz. No matter what I tried, the vfo refused to oscillate at 3.6 Mhz!!
?
?The possibility of a rotor contact issue, on the vfo tuning cap was eliminated.
?
?After some had scratching, I began to suspect that a VHF parasitic oscillation was involved. I installed a 33 ohm resistor, in series with the control grid lead, of the oscillator tube. The problem was cured.
?
?It was my guess that?3.6 Mhz?was a sub harmonic of the frequency of the undesired VHF parasitic oscillation, that was occurring, simultaneously, with the desired HF oscillation.
?
?After that experience, I began installing parasitic suppressors, as a matter of routine.
?
?????? 73 de Ron??
??

________________________________
From: Walt Hutchens <waltah at earthlink.net>
To: HBR Receiver List <hbr at mailman.qth.net> 
Sent: Sunday, January 5, 2014 5:13 PM
Subject: Re: [HBR] HBR - BFO progress


Ron said:

> ?I see a problem with the suggested Colpitts circuit, that you
> provided a?link to. If I understand the labeling on the schematic
> diagram correctly, there is a .01 mfd capacitor, on each end of the
> RFC. The cap on the left side of the choke, is electrically in shunt
> with the 180 pf cap, that comprises part of the oscillator tank
> circuit. This will profoundly alter the feedback ratio, and the
> resonant freq of the tank ckt. ?In fact, the feedback ratio will be
> altered to the point that?I seriously doubt that the circuit will
> oscillate at all.

That's a problematic circuit either way. Without the 0.01 mfd cap it
will oscillate at roughly the frequency set by the tank circuit but
the choke is in shunt with the 180 mmf capacitor. You really don't
want a choke in a VFO circuit: They are terribly unstable.

I've never had any trouble as simple as getting the tap right for a
Hartley. The turns ratio is the same as the proper one for the caps in
a Colpitts circuit. If I remember correctly the command sets use a
separate winding for feedback in that BFO; that's another way to do it
and the turns ratio is the same as the ratio appropriate for a Hartley
or Colpitts circuit.

You can get rid of the choke in a Colpitts circuit by using a resistor
instead and for the very highest Q (hi-Q helps with stability against
tube gain variations due to structural and voltage fluctuations ...)
tap the coil APPROXIMATELY at zero RF voltage, letting the capacitors
set the exact feedback ratio and/or tuning range.

As long as the voltage across the resistor is just a small fraction of
the total the effect on circuit Q will be unimportant.

Feedback ratios really aren't supercritical. The amplitude of
oscillation in a class 'C' oscillator is set by the load imposed when
the grid is driven positive over a fairly wide range of ratios. (The
grid is then basically a shunt diode that eats the excess energy.)
Only if there isn't enough feedback or it becomes so great that the
tube goes into blocking oscillations will there be trouble.

(Blocking: the grid capacitor charges so much during the positive
swing that when the tank circuit swings the grid negative the tube
cannot conduct again even on the next positive swing of the tank.
Instead the capacitor must discharge through the grid leak resistor
for several or many cycles of the RF before the tube again conducts.
This is a good thing for a superregenerative detector, not so good for
a BFO, LO, etc. Cure involves some combination of less feedback, lower
grid leak resistor, and smaller grid coupling cap.)

Well ... long leads and/or the latest UHF-capable tube types can get
you VHF parasitics if you don't take precautions and these parasitics
may occur over just a part of a cycle of the intended oscillation
frequency. But once you've seen this you'll recognize it. Horrific
crashing noise when you tune the oscillator is one symptom because
there's very high VHF current in the capacitor bearings or contacts.

Nearly all construction project articles have clear enough directions
to get you past such issues. It's best to NOT substitute 'better'
tubes than those specified. 6SK7 replaced by a 6BZ6? GOOD chance of
VHF parasitics there, unless you use countermeasures.

This is true throughout the RF-IF stages of a receiver. Also in such
stages 'hotter' tubes routinely need a cross-socket shield to separate
input from output.

The latest tube types will require extra work compared to those of the
50's and if the project you're doing is from a 50's magazine article
the how-to for dealing with the later tubes won't be in the article or
circuit. This can be about the most challenging troubleshooting you'll
see.

All resistors in an oscillator should be the modern carbon film ones:
They're more stable in every respect than the vintage ones. AVOID
bypass-type disk ceramics in an oscillator, even for bypass jobs: They
are NOT stable, indeed their capacitance may vary with the voltage
across them as well as temperature.

Mica bypasses work well in oscillators, even the larger 'postage
stamp' micas.

You're looking for a few parts per million stability, right? Receiver
oscillators are precision instruments: You can breadboard them with
'whatever' parts but use only the best for the actual build.

Walt Hutchens
KJ4KV

From waltah at earthlink.net  Sun Jan  5 22:56:53 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Sun, 5 Jan 2014 22:56:53 -0500
Subject: [HBR] HBR - BFO progress
In-Reply-To: <1388976029.29767.YahooMailNeo@web160101.mail.bf1.yahoo.com>
References: <20140104092951.c047917b6272adbdbe8692f8c22b6543.0b23a61604.wbe@email09.secureserver.net>
	<BFEA0DC7BC1A431EA9F46BF5B0226B15@gerald2369b375>
	<52C98A06.80501@comcast.net>
	<1388948768.29571.YahooMailNeo@web160105.mail.bf1.yahoo.com>
	<1012674566.20140105171339@earthlink.net>
	<1388976029.29767.YahooMailNeo@web160101.mail.bf1.yahoo.com>
Message-ID: <1023960045.20140105225653@earthlink.net>

Ron said:

> After some had scratching, I began to suspect that a VHF parasitic
> oscillation was involved. I installed a 33 ohm resistor, in series
> with the control grid lead, of the oscillator tube. The problem was
> cured.
> ?
> ?It was my guess that?3.6 Mhz?was a sub harmonic of the frequency of
> the undesired VHF parasitic oscillation, that was occurring,
> simultaneously, with the desired HF oscillation.
> ?
> ?After that experience, I began installing parasitic suppressors, as
> a matter of routine.

WOW ... The diagnosis sounds right: AT 3.6 mcs the parasite either
sucked so much energy from the intended tank circuit that it killed
oscillation or developed enough grid bias to do the same.

Now that's one I've never had.

Sometimes probing around with a frequency counter will turn up a
strong signal. Another old trick is touching things with the point of
a lead pencil (HV safety issue ...) which may kill a VHF oscillation
and suddenly make the circuit behave normally even if its off
frequency.

I like to build in a test point for oscillator grid current -- like
use a 47k grid resistor but the ground end goes to a 1k resistor from
a test point to ground. A DVM will show the current which should
behave smoothly as you tune, a frequency counter may work there as
well.

I too use parasitic suppressors as a matter of routine. The latest
tubes are excellent, they can often save you a stage in a receiver,
but you pay for the savings getting the thing tamed.

Walt Hutchens
KJ4KV


From whitebear1122 at comcast.net  Mon Jan  6 15:12:19 2014
From: whitebear1122 at comcast.net (whitebear1122 at comcast.net)
Date: Mon, 6 Jan 2014 20:12:19 +0000 (UTC)
Subject: [HBR] WTB:  Miller 1730 IF Transformers
In-Reply-To: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
Message-ID: <1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>




Greetings and Happy New Year from the Frozen Tundra of Minnesota.? Brrrrr.. 

? 

Want to Buy:? two Miller 1730 IF Transformers.? I've just completed a major radio sell off that consumed most of my radio time for the past 3 years, leaving my HBR project on hold.??I am now proceeding to build my HBR and I'm looking for 2 parts. 

? 

I wanted to build an HBR13 but I couldn't find the Miller 1730 1800 Kc IF transformers.? I do have the 4 Miller 1709/1710 100 Kc transformers, just missing the 1730's.?? So I decided to build the?HBR-12.? I was?recently reminded that the ARC-5 BC-454 IF transformers are 1415 Kc and can be retuned?up to 1610 Kc and be substituted for the 1730's, although the BC454's are maybe 9x larger in volume.? I sought them out and have a set now and I'm dimensioning the main chassis for them.?? 

? 

Before I start cutting metal I wanted to make one last request for?2 Miller 1730 IF transformers.?Has anyone?on here used the? BC454 1415Kc IF's in an HBR13 before? 

? 

Thanks.? 73, Scott WA9WFA 

From waltah at earthlink.net  Mon Jan  6 22:48:26 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Mon, 6 Jan 2014 22:48:26 -0500
Subject: [HBR] Program to draw circuit diagrams?
In-Reply-To: <1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
References: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
	<1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
Message-ID: <1007105249.20140106224826@earthlink.net>

Years and years I've been trying to settle on a program for drawing
circuit diagrams. There's lots of drawing programs out there but most
cost real money, most of the ones that claim to do circuits have --
ick! -- ICs and stuff that's suitable only for SUPPORT of real
electronics (like: has vacuum tubes in it), and the ones that ARE low
cost and seem generally capable would require building a library from
the beginning.

Any recommendations? If I can't find a suitable wheel that has already
been invented I'll probably see if I can come up with a library for
the drawing program that's part of Open Office.

Yeah, my freehand sketches are nearly unreadable. Even by me.

Walt Hutchens
KJ4KV


From kf4tap at yahoo.com  Tue Jan  7 00:11:10 2014
From: kf4tap at yahoo.com (Brian Ford)
Date: Mon, 6 Jan 2014 21:11:10 -0800 (PST)
Subject: [HBR] Program to draw circuit diagrams?
In-Reply-To: <1007105249.20140106224826@earthlink.net>
References: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>	<1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
	<1007105249.20140106224826@earthlink.net>
Message-ID: <1389071470.48683.YahooMailNeo@web121604.mail.ne1.yahoo.com>

tubepad?






On Monday, January 6, 2014 9:48 PM, Walt Hutchens <waltah at earthlink.net> wrote:
 
Years and years I've been trying to settle on a program for drawing
circuit diagrams. There's lots of drawing programs out there but most
cost real money, most of the ones that claim to do circuits have --
ick! -- ICs and stuff that's suitable only for SUPPORT of real
electronics (like: has vacuum tubes in it), and the ones that ARE low
cost and seem generally capable would require building a library from
the beginning.

Any recommendations? If I can't find a suitable wheel that has already
been invented I'll probably see if I can come up with a library for
the drawing program that's part of Open Office.

Yeah, my freehand sketches are nearly unreadable. Even by me.

Walt Hutchens
KJ4KV


______________________________________________________________
HBR mailing list
Home: http://mailman.qth.net/mailman/listinfo/hbr
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:HBR at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

From mmab at cox.net  Tue Jan  7 10:08:21 2014
From: mmab at cox.net (Michael A. Bittner)
Date: Tue, 7 Jan 2014 07:08:21 -0800
Subject: [HBR] Program to draw circuit diagrams?
References: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>	<1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net><1007105249.20140106224826@earthlink.net>
	<AtBF1n00845oxQM01tBHbv>
Message-ID: <906CABB78995480680C03842DAD0105C@pcb5f47b1b5375>

I started out using "Tubepad", but eventually settled on a method that works better for me.  I scan a schematic diagram of some radio or other equipment from a magazine, SAMS Folder, manual or other source that has the symbols and lettering that I need for whatever new schematic I am composing.  I then store it as a JPEG and edit it in uSoft Paint.  Under "Attributes" in "Paint" I expand the width of the drawing to include the JPEG plus blank space for my new drawing.  Then I copy and paste from the JPEG to the blank space to build up my new schematic using the JPEG as a palate for all the symbols and lettering I need.  I use "line draw" for the wiring and the "circle draw", "rectangle draw", "erase", "move" and other faculties of "Edit" to complete the new schematic. I use Photoshop to "move" whole sections of the schematic that are too big to fit within my screen, and when the new schematic is complete, I "crop" it to delete the scanned schematic that I have been using as a palate.  This method results in drawings that have the quality and resolution (resolution much better than Tubepad) of the original scanned schematic.  I have used this method for schematics that accompany articles of mine that have appeared in "Electric Radio" magazine and have received compliments on them from readers who also question "what program did I use to make them".  Try my method and see if it works for you.  Mike, W6MAB
  ----- Original Message ----- 
  From: Brian Ford 
  To: HBR Receiver List 
  Sent: Monday, January 06, 2014 9:11 PM
  Subject: Re: [HBR] Program to draw circuit diagrams?


  tubepad?

  On Monday, January 6, 2014 9:48 PM, Walt Hutchens <waltah at earthlink.net> wrote:
   
  Years and years I've been trying to settle on a program for drawing
  circuit diagrams. There's lots of drawing programs out there but most
  cost real money, most of the ones that claim to do circuits have --
  ick! -- ICs and stuff that's suitable only for SUPPORT of real
  electronics (like: has vacuum tubes in it), and the ones that ARE low
  cost and seem generally capable would require building a library from
  the beginning.

  Any recommendations? If I can't find a suitable wheel that has already
  been invented I'll probably see if I can come up with a library for
  the drawing program that's part of Open Office.

  Yeah, my freehand sketches are nearly unreadable. Even by me.

  Walt Hutchens
  KJ4KV


From whitebear1122 at comcast.net  Tue Jan  7 10:26:31 2014
From: whitebear1122 at comcast.net (whitebear1122 at comcast.net)
Date: Tue, 7 Jan 2014 15:26:31 +0000 (UTC)
Subject: [HBR] Question: Why Did the 2nd Oscillator/Mixer Shield box
 Disappear in the HBR-13?
In-Reply-To: <1389071470.48683.YahooMailNeo@web121604.mail.ne1.yahoo.com>
Message-ID: <881172752.388550.1389108391768.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>






I have shifted gears last week and decided to pursue the HBR-13 instead of the 12 so now I'm adjusting the dimensions on my paper parts?placement diagram to accomodate the two additional 1610 Kc IF transformers and the additional 100 Kc transformer.? 

? 

I know that the?2nd Oscillator/Mixer was once inside?a small shield box on the HBR-11/12 but suddenly was no longer needed on the HBR-13.??What changed on the HBR-13 design that allowed the crystal oscillator circuit to no longer require a shield?? 

? 

73, Scott WA9WFA? 

?

From smithab11 at comcast.net  Tue Jan  7 11:17:04 2014
From: smithab11 at comcast.net (B. Smith)
Date: Tue, 07 Jan 2014 11:17:04 -0500
Subject: [HBR] Program to draw circuit diagrams?
In-Reply-To: <906CABB78995480680C03842DAD0105C@pcb5f47b1b5375>
References: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>	<1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net><1007105249.20140106224826@earthlink.net>	<AtBF1n00845oxQM01tBHbv>
	<906CABB78995480680C03842DAD0105C@pcb5f47b1b5375>
Message-ID: <52CC2880.4050205@comcast.net>

I use CorelDraw and standard ARRL schematic symbols which are in a 
CorelDraw  format. You can import tube pad symbols, jpeg etc into your 
drawing and edit them at the same time.  The ARRL symbols which are in 
Cdr format can be dissected and modified as desired, symbols can be 
enlarged, reduced , stretched etc. Or you can modify a symbol and save 
it.    I use an older version X3 which is dated 2005 and runs fine on 
Windows 7. Available on ePay. I can email the  ARRL cdr file to anyone 
that needs it, or you can search on the ARRL site.
The article on the use of CorelDraw was by  the late N0SS, Mr Tom Hammond.

k4che


On 1/7/2014 10:08 AM, Michael A. Bittner wrote:
> I started out using "Tubepad", but eventually settled on a method that works better for me.  I scan a schematic diagram of some radio or other equipment from a magazine, SAMS Folder, manual or other source that has the symbols and lettering that I need for whatever new schematic I am composing.  I then store it as a JPEG and edit it in uSoft Paint.  Under "Attributes" in "Paint" I expand the width of the drawing to include the JPEG plus blank space for my new drawing.  Then I copy and paste from the JPEG to the blank space to build up my new schematic using the JPEG as a palate for all the symbols and lettering I need.  I use "line draw" for the wiring and the "circle draw", "rectangle draw", "erase", "move" and other faculties of "Edit" to complete the new schematic. I use Photoshop to "move" whole sections of the schematic that are too big to fit within my screen, and when the new schematic is complete, I "crop" it to delete the scanned schematic that I have been using as a
>    palate.  This method results in drawings that have the quality and resolution (resolution much better than Tubepad) of the original scanned schematic.  I have used this method for schematics that accompany articles of mine that have appeared in "Electric Radio" magazine and have received compliments on them from readers who also question "what program did I use to make them".  Try my method and see if it works for you.  Mike, W6MAB
>    ----- Original Message -----
>    From: Brian Ford
>    To: HBR Receiver List
>    Sent: Monday, January 06, 2014 9:11 PM
>    Subject: Re: [HBR] Program to draw circuit diagrams?
>
>
>    tubepad?
>
>    On Monday, January 6, 2014 9:48 PM, Walt Hutchens <waltah at earthlink.net> wrote:
>     
>    Years and years I've been trying to settle on a program for drawing
>    circuit diagrams. There's lots of drawing programs out there but most
>    cost real money, most of the ones that claim to do circuits have --
>    ick! -- ICs and stuff that's suitable only for SUPPORT of real
>    electronics (like: has vacuum tubes in it), and the ones that ARE low
>    cost and seem generally capable would require building a library from
>    the beginning.
>
>    Any recommendations? If I can't find a suitable wheel that has already
>    been invented I'll probably see if I can come up with a library for
>    the drawing program that's part of Open Office.
>
>    Yeah, my freehand sketches are nearly unreadable. Even by me.
>
>    Walt Hutchens
>    KJ4KV
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>



From smithab11 at comcast.net  Tue Jan  7 19:20:58 2014
From: smithab11 at comcast.net (B. Smith)
Date: Tue, 07 Jan 2014 19:20:58 -0500
Subject: [HBR] Program to draw circuit diagrams?
In-Reply-To: <906CABB78995480680C03842DAD0105C@pcb5f47b1b5375>
References: <1261884923.371948.1389038911199.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>	<1190815853.372032.1389039139195.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net><1007105249.20140106224826@earthlink.net>	<AtBF1n00845oxQM01tBHbv>
	<906CABB78995480680C03842DAD0105C@pcb5f47b1b5375>
Message-ID: <52CC99EA.1000907@comcast.net>

  The source document for CorelDraw ARRL schematic symbols can be found 
at the ARRL site link below  for "QST Binaries" and can be found by 
looking under  the year 2001 and the month of October, the author is 
N0SS. Title "Schematic.zip"
BTW CorelDraw has a neat feature of "Interactive Connector Tool which 
automatic routes and connects a line following 90 degrees turns etc. 
between the nodes of the symbols.  Schematic.zip also contain PC Pads 
files for designing PC boards.

There are also schematic files for "Windows Paint" listed,  Look under 
October 1993 and December 2000 by W1RIL. "Schematics at your Fingertips".

k4che

http://www.arrl.org/files/file/QST%2520Binaries/


From hb9bnk at uska.ch  Mon Jan 13 05:09:47 2014
From: hb9bnk at uska.ch (Werner, HB9BNK)
Date: Mon, 13 Jan 2014 11:09:47 +0100
Subject: [HBR] Need advice on Miller 1730 transformers
Message-ID: <52D3BB6B.50003@uska.ch>

Back around 1970, I built a HBR-13C (with great help from Alex 
Stewart). Having studied the valuable reflections-CD and the 
discussions here, I recently pulled the receiver from the attic 
and try now, to get it running again - and improve, if possible.

Now, I found, that some of the I.F.filters cannot be tuned, 
because the core's are locked by whatever ...

Can someone give me an advice, how to free the core ?

Thanks and 73

Werner, HB9BNK

From wrcromwell at gmail.com  Mon Jan 13 08:59:51 2014
From: wrcromwell at gmail.com (Bill Cromwell)
Date: Mon, 13 Jan 2014 08:59:51 -0500
Subject: [HBR] Need advice on Miller 1730 transformers
In-Reply-To: <52D3BB6B.50003@uska.ch>
References: <52D3BB6B.50003@uska.ch>
Message-ID: <52D3F157.9000809@gmail.com>

On 01/13/2014 05:09 AM, Werner, HB9BNK wrote:
> Back around 1970, I built a HBR-13C (with great help from Alex 
> Stewart). Having studied the valuable reflections-CD and the 
> discussions here, I recently pulled the receiver from the attic and 
> try now, to get it running again - and improve, if possible.
>
> Now, I found, that some of the I.F.filters cannot be tuned, because 
> the core's are locked by whatever ...
>
> Can someone give me an advice, how to free the core ?
>
> Thanks and 73
>
> Werner, HB9BNK

Hi Werner,

I haven't done this because I haven't had the problem. Other hams have 
reported success using heat. They use something like a metal allen 
wrench or a small screwdriver - NOT to force the slug (core) - to apply 
the heat. Do not use the the metal tool to force the slug or you will 
break the slug. You probably already knew that. Apply heat from a 
soldering iron or solder gun to the metal part of the tool to transfer 
heat to the slug. The heat will transfer from the soldering iron, 
through the metal tool, and into the slug. Be careful, of course, to not 
let the hot metal or iron touch anything else. Try just a little heat at 
first to see if some of the wax has migrated into the 'threads' and to 
soften it. More heat if needed. The expansion/contraction you hope will 
break the 'bond' and free the slug.

If the slug is already broken you will have to crumble it out of the 
form and replace it. You probably already knew that, too. I mention 
those things since there will be readers of this thread who would not 
otherwise know.

Good luck with your HBR project. Let us know how this goes for you. I 
have been accumulating parts in a bin for an HBR or my own. I am interested.

73,

Bill  KU8H

From Gcromer at usit.net  Mon Jan 13 09:56:05 2014
From: Gcromer at usit.net (Gerald Cromer)
Date: Mon, 13 Jan 2014 09:56:05 -0500
Subject: [HBR]  Need advice on Miller 1730 transformers
References: <52D3BB6B.50003@uska.ch>
Message-ID: <F09D450D5E78438AA96BB426CCBEAE4B@gerald2369b375>

I use to restore antique  radios and I had that same problem.
The slugs will get set and when you try to turn them they will crack and 
then
when you try to turn them they expand and won't turn. I use to take a small
drill bit and drill out the slug a little at a time. Keep enlarging the 
drill bit
until the slug falls apart and then you can  shake the parts out or pick 
them out..
I DIDN'T use a drill. I only use the bit by hand. If you us a drill, the 
power will
cause the bit to grab the slug and will twist the coil and brake it loose 
and the leads.
You use to could buy a package of different sized slugs at the radio parts
store, but they have all gone by the way side now. Find some other IF cans
and rob the slug out of them. Remember that brass slugs up the frequency
as you tune them into the coil and that iron slugs lower the  frequency
as you turn them into the slug.  If the slug isn't cracked you can heat the 
IF
can with a hair drier and something's that will loosen the slug and it will 
turn.
Once the slug cracks, it over with it turning. If you find out that the new
slug it loose in the old threads, take a small rubber band and
put one strand of it in the hole before you start the slug in the can.
Hope this helps.
Gerald K4NHN
Cayce, SC



----- Original Message ----- 
From: "Werner, HB9BNK" <hb9bnk at uska.ch>
To: <hbr at mailman.qth.net>
Sent: Monday, January 13, 2014 5:09 AM
Subject: [HBR] Need advice on Miller 1730 transformers


> Back around 1970, I built a HBR-13C (with great help from Alex Stewart). 
> Having studied the valuable reflections-CD and the discussions here, I 
> recently pulled the receiver from the attic and try now, to get it running 
> again - and improve, if possible.
>
> Now, I found, that some of the I.F.filters cannot be tuned, because the 
> core's are locked by whatever ...
>
> Can someone give me an advice, how to free the core ?
>
> Thanks and 73
>
> Werner, HB9BNK
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html 


From sswhite at mchsi.com  Mon Jan 13 10:18:53 2014
From: sswhite at mchsi.com (Steve)
Date: Mon, 13 Jan 2014 09:18:53 -0600
Subject: [HBR] 50Khz IF Transformer fior new Build
Message-ID: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>

I am in the process of gathering parts and I have been dealing with trying
to find IF Transformers.   I have quite a few 265Khz ones that will need
modifications, 5 ea  85Khz ones from an ARC 5  and some 50Khz ones from a
junker National NC300.  So the big question for me is which sets should I
use?  Modifications of the 265 is quite a task, so it seems to come down to
using the 85Khz ones whihc there is plenty written about how to do that or
use the 50Khz ones from the National.  Any reason that I should not use the
50 Khz ones, understanding that I have to make a few changes in the
oscillator frequencies...The 50 Khz ones would be easy to use and mount on
the chassis.  This the last major hurdle for parts that I have.
 
Steve NU0P

From smithab11 at comcast.net  Mon Jan 13 12:40:44 2014
From: smithab11 at comcast.net (B. Smith)
Date: Mon, 13 Jan 2014 12:40:44 -0500
Subject: [HBR] 50Khz IF Transformer fior new Build
In-Reply-To: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>
References: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>
Message-ID: <52D4251C.8020403@comcast.net>

Be sure an choose your oscillator frequency carefully due to possible 
local AM broadcast.
When using an IF that is different then published you can expect a few 
"birdies" and you will have to change the mixer injection crystal. So 
you may want to do the math first.
http://k4che.com/HBR/Testing/Progress%20Testing%20pg%201.htm

On 1/13/2014 10:18 AM, Steve wrote:
> I am in the process of gathering parts and I have been dealing with trying
> to find IF Transformers.   I have quite a few 265Khz ones that will need
> modifications, 5 ea  85Khz ones from an ARC 5  and some 50Khz ones from a
> junker National NC300.  So the big question for me is which sets should I
> use?  Modifications of the 265 is quite a task, so it seems to come down to
> using the 85Khz ones whihc there is plenty written about how to do that or
> use the 50Khz ones from the National.  Any reason that I should not use the
> 50 Khz ones, understanding that I have to make a few changes in the
> oscillator frequencies...The 50 Khz ones would be easy to use and mount on
> the chassis.  This the last major hurdle for parts that I have.
>   
> Steve NU0P
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


From sswhite at mchsi.com  Tue Jan 14 09:37:26 2014
From: sswhite at mchsi.com (Steve)
Date: Tue, 14 Jan 2014 08:37:26 -0600
Subject: [HBR] 50Khz IF Transformer fior new Build
In-Reply-To: <52D4251C.8020403@comcast.net>
References: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>
	<52D4251C.8020403@comcast.net>
Message-ID: <9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>

AS I began looking at the "as designed" IF freq I find that it is the same
freq as one of the local high power AM stations  (1600Khz) one other choice
I have is 1700 and there is a much lower power signal there when I listen
with my IC756.  It is complety quite between 1700 and 1800, totally dead
here.  Is this range then my best choice of IF???  Or can I get by with 1700
with good shielding of the IF???  The station on 1700 is not really very
strong but I can copy it ok...  What to do??

Steve

 

-----Original Message-----
From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
Behalf Of B. Smith
Sent: Monday, January 13, 2014 11:41 AM
To: HBR Receiver List
Subject: Re: [HBR] 50Khz IF Transformer fior new Build

Be sure an choose your oscillator frequency carefully due to possible local
AM broadcast.
When using an IF that is different then published you can expect a few
"birdies" and you will have to change the mixer injection crystal. So you
may want to do the math first.
http://k4che.com/HBR/Testing/Progress%20Testing%20pg%201.htm

On 1/13/2014 10:18 AM, Steve wrote:
> I am in the process of gathering parts and I have been dealing with trying
> to find IF Transformers.   I have quite a few 265Khz ones that will need
> modifications, 5 ea  85Khz ones from an ARC 5  and some 50Khz ones 
> from a junker National NC300.  So the big question for me is which 
> sets should I use?  Modifications of the 265 is quite a task, so it 
> seems to come down to using the 85Khz ones whihc there is plenty 
> written about how to do that or use the 50Khz ones from the National.  
> Any reason that I should not use the 50 Khz ones, understanding that I 
> have to make a few changes in the oscillator frequencies...The 50 Khz 
> ones would be easy to use and mount on the chassis.  This the last major
hurdle for parts that I have.
>   
> Steve NU0P
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net Please help support this email 
> list: http://www.qsl.net/donate.html
>

______________________________________________________________
HBR mailing list
Home: http://mailman.qth.net/mailman/listinfo/hbr
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:HBR at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html


From daileyservices at qwest.net  Tue Jan 14 09:47:29 2014
From: daileyservices at qwest.net (TC Dailey)
Date: Tue, 14 Jan 2014 07:47:29 -0700
Subject: [HBR] 50Khz IF Transformer fior new Build
References: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz><52D4251C.8020403@comcast.net>
	<9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>
Message-ID: <391DAE58C9D04080A3D9A8EEAE5B84E9@w0eaj>

Considering that the ORIGINAL was 1710, I think you've hit the jackpot.

Tom
----- Original Message ----- 
From: "Steve" <sswhite at mchsi.com>

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com


From hbrnut at suddenlink.net  Tue Jan 14 10:04:09 2014
From: hbrnut at suddenlink.net (WA5VGO)
Date: Tue, 14 Jan 2014 09:04:09 -0600
Subject: [HBR] 50Khz IF Transformer fior new Build
In-Reply-To: <9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>
References: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>
	<52D4251C.8020403@comcast.net>
	<9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>
Message-ID: <69F9479B-02B0-461D-81DB-CED2A667758F@suddenlink.net>

I believe 1710 is reserved in the United States for travelers information stations, so that would be a pretty safe choice. 

Darrell



> On Jan 14, 2014, at 8:37 AM, "Steve" <sswhite at mchsi.com> wrote:
> 
> AS I began looking at the "as designed" IF freq I find that it is the same
> freq as one of the local high power AM stations  (1600Khz) one other choice
> I have is 1700 and there is a much lower power signal there when I listen
> with my IC756.  It is complety quite between 1700 and 1800, totally dead
> here.  Is this range then my best choice of IF???  Or can I get by with 1700
> with good shielding of the IF???  The station on 1700 is not really very
> strong but I can copy it ok...  What to do??
> 

From hb9bnk at uska.ch  Tue Jan 14 10:33:34 2014
From: hb9bnk at uska.ch (Werner, HB9BNK)
Date: Tue, 14 Jan 2014 16:33:34 +0100
Subject: [HBR] Advice on Miller 1730 transformers
Message-ID: <52D558CE.9030003@uska.ch>

Hi Bill and Gerald,

thank you both very much for profound suggestions to help with my 
slugs ! Level 1 : heat; Level 2: hand-drill softly and replace 
(both suggestions ended up in my 'reconstruction log book 'for 
further references).

So far, Level 1 has helped to release a reluctant slug.

On checking further, I found a wobbly (?) 1730 (T1B in the 
HB*-13C). After removing the can, I found a broken coil form - 
electrically ok, but physically spoiled. I will try to stabilize 
and then tune this filter precisely to the 1600 kHz IF (having a 
1700 kHz quartz), so that I dont have to touch it any more. By the 
way: the second filter (T1A) 1730 is of different construction 
inside, so I got two versions.

I will keep you informed  !

73 Werner, HB9BNK

From smithab11 at comcast.net  Tue Jan 14 11:48:58 2014
From: smithab11 at comcast.net (B. Smith)
Date: Tue, 14 Jan 2014 11:48:58 -0500
Subject: [HBR] 50Khz IF Transformer fior new Build
In-Reply-To: <9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>
References: <36EF9AA55C8547EB9BB71FBF2E884632@Ghz>	<52D4251C.8020403@comcast.net>
	<9AEE9AE9125F4AC384F8B0258CE8C753@Ghz>
Message-ID: <52D56A7A.2070201@comcast.net>

Be sure an consult your AM station listings, either local or FCC data 
base for stations. Often some of these AM stations are off the air as 
they are remoted and there "is no one there". TIS does use 1.710 here in 
Chickenland but that is low power unless it is down the street.
BTW crystals below 4 Mcs  are becoming expensive. International prices  
all most triple when ordering below "4 Mcs".  Maybe look for a FT-243 
crystal and  get out the tooth paste.  :-)  I see that AF4J has one 
rock  "advertised" on his site for 1.700, perhaps that would be a candidate.

http://www.af4k.com/FT243crystals1500-1999khz.htm


On 1/14/2014 9:37 AM, Steve wrote:
> AS I began looking at the "as designed" IF freq I find that it is the same
> freq as one of the local high power AM stations  (1600Khz) one other choice
> I have is 1700 and there is a much lower power signal there when I listen
> with my IC756.  It is complety quite between 1700 and 1800, totally dead
> here.  Is this range then my best choice of IF???  Or can I get by with 1700
> with good shielding of the IF???  The station on 1700 is not really very
> strong but I can copy it ok...  What to do??
>
> Steve
>
>   
>
> -----Original Message-----
> From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
> Behalf Of B. Smith
> Sent: Monday, January 13, 2014 11:41 AM
> To: HBR Receiver List
> Subject: Re: [HBR] 50Khz IF Transformer fior new Build
>
> Be sure an choose your oscillator frequency carefully due to possible local
> AM broadcast.
> When using an IF that is different then published you can expect a few
> "birdies" and you will have to change the mixer injection crystal. So you
> may want to do the math first.
> http://k4che.com/HBR/Testing/Progress%20Testing%20pg%201.htm
>
> On 1/13/2014 10:18 AM, Steve wrote:
>> I am in the process of gathering parts and I have been dealing with trying
>> to find IF Transformers.   I have quite a few 265Khz ones that will need
>> modifications, 5 ea  85Khz ones from an ARC 5  and some 50Khz ones
>> from a junker National NC300.  So the big question for me is which
>> sets should I use?  Modifications of the 265 is quite a task, so it
>> seems to come down to using the 85Khz ones whihc there is plenty
>> written about how to do that or use the 50Khz ones from the National.
>> Any reason that I should not use the 50 Khz ones, understanding that I
>> have to make a few changes in the oscillator frequencies...The 50 Khz
>> ones would be easy to use and mount on the chassis.  This the last major
> hurdle for parts that I have.
>>    
>> Steve NU0P
>> ______________________________________________________________
>> HBR mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/hbr
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:HBR at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net Please help support this email
>> list: http://www.qsl.net/donate.html
>>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


From ianmwilson73 at gmail.com  Thu Jan 16 19:12:59 2014
From: ianmwilson73 at gmail.com (Ian Wilson)
Date: Thu, 16 Jan 2014 16:12:59 -0800
Subject: [HBR] Need help with noise
Message-ID: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>

Disclaimer: this is not an HBR. However, there are some receiver-builder
greats on this list so I hope this is OK.

My receiver design is a sort-of 75S3C knockoff with newer tube types
and a number of other changes forced by available parts. It is a dual
conversion scheme with fixed 2nd IF of 455kHz.

6EJ7 RF amplifier. 6DJ8 first mixer. 3.075MHz bandpass filter
(+-75kHz BW). 6EA8 second mixer. 455kHz mechanical filter (2.5kHz BW).
2x6EH7 IF amplifier. Beam deflection product detector. AF stage
borrowed from the 75S3. Uses a PTO (actually Dubrow but very
similar to Collins) for main tuning.

Anyway. This works pretty well from some points of view. It is stable
enough and the birdies are under control. However, there is a great
deal of 'impulse' noise on the audio. This must be coming in through
the front end stages. If I short the IF strip input I can hear a faint hiss.
If I short the first mixer input I can hear some band noise but well
below the level with an antenna connected.

With a (very poor) antenna connected I can resolve CW and SSB
signals but both are very noisy. Listening on another receiver (with
a much better antenna), the same signals are way above the band
noise level.

I have tried shielding the input tuned circuits (there is a bandswitched
pair of inductors scavenged from an HR-10, and a dual 100pF capacitor)
with no discernible effect.

The audio bandwidth is not excessive (5kHz perhaps).

Would welcome any suggestions. I have noticed before with this setup that
some receivers handle the conditions well, and some have lots of
apparent band noise.

73, ian K3IMW




On Sun, Jan 5, 2014 at 7:56 PM, Walt Hutchens <waltah at earthlink.net> wrote:

> Ron said:
>
> > After some had scratching, I began to suspect that a VHF parasitic
> > oscillation was involved. I installed a 33 ohm resistor, in series
> > with the control grid lead, of the oscillator tube. The problem was
> > cured.
> >
> >  It was my guess that 3.6 Mhz was a sub harmonic of the frequency of
> > the undesired VHF parasitic oscillation, that was occurring,
> > simultaneously, with the desired HF oscillation.
> >
> >  After that experience, I began installing parasitic suppressors, as
> > a matter of routine.
>
> WOW ... The diagnosis sounds right: AT 3.6 mcs the parasite either
> sucked so much energy from the intended tank circuit that it killed
> oscillation or developed enough grid bias to do the same.
>
> Now that's one I've never had.
>
> Sometimes probing around with a frequency counter will turn up a
> strong signal. Another old trick is touching things with the point of
> a lead pencil (HV safety issue ...) which may kill a VHF oscillation
> and suddenly make the circuit behave normally even if its off
> frequency.
>
> I like to build in a test point for oscillator grid current -- like
> use a 47k grid resistor but the ground end goes to a 1k resistor from
> a test point to ground. A DVM will show the current which should
> behave smoothly as you tune, a frequency counter may work there as
> well.
>
> I too use parasitic suppressors as a matter of routine. The latest
> tubes are excellent, they can often save you a stage in a receiver,
> but you pay for the savings getting the thing tamed.
>
> Walt Hutchens
> KJ4KV
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

From radioconnection at gmail.com  Thu Jan 16 21:01:51 2014
From: radioconnection at gmail.com (Peter Bertini)
Date: Thu, 16 Jan 2014 21:01:51 -0500
Subject: [HBR] Need help with noise
In-Reply-To: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
Message-ID: <CA+uDY2Ska4mD0fVGK5SSpiwNNwcmriqZdxwQKsHC3kiKjCQUmw@mail.gmail.com>

Did you check the RF stage for parasitic oscillations? That might be a
possibility if things seem squirrely.

Pete


On Thu, Jan 16, 2014 at 7:12 PM, Ian Wilson <ianmwilson73 at gmail.com> wrote:

> Disclaimer: this is not an HBR. However, there are some receiver-builder
> greats on this list so I hope this is OK.
>
> My receiver design is a sort-of 75S3C knockoff with newer tube types
> and a number of other changes forced by available parts. It is a dual
> conversion scheme with fixed 2nd IF of 455kHz.
>
> 6EJ7 RF amplifier. 6DJ8 first mixer. 3.075MHz bandpass filter
> (+-75kHz BW). 6EA8 second mixer. 455kHz mechanical filter (2.5kHz BW).
> 2x6EH7 IF amplifier. Beam deflection product detector. AF stage
> borrowed from the 75S3. Uses a PTO (actually Dubrow but very
> similar to Collins) for main tuning.
>
> Anyway. This works pretty well from some points of view. It is stable
> enough and the birdies are under control. However, there is a great
> deal of 'impulse' noise on the audio. This must be coming in through
> the front end stages. If I short the IF strip input I can hear a faint
> hiss.
> If I short the first mixer input I can hear some band noise but well
> below the level with an antenna connected.
>
> With a (very poor) antenna connected I can resolve CW and SSB
> signals but both are very noisy. Listening on another receiver (with
> a much better antenna), the same signals are way above the band
> noise level.
>
> I have tried shielding the input tuned circuits (there is a bandswitched
> pair of inductors scavenged from an HR-10, and a dual 100pF capacitor)
> with no discernible effect.
>
> The audio bandwidth is not excessive (5kHz perhaps).
>
> Would welcome any suggestions. I have noticed before with this setup that
> some receivers handle the conditions well, and some have lots of
> apparent band noise.
>
> 73, ian K3IMW
>
>
>
>
> On Sun, Jan 5, 2014 at 7:56 PM, Walt Hutchens <waltah at earthlink.net>
> wrote:
>
> > Ron said:
> >
> > > After some had scratching, I began to suspect that a VHF parasitic
> > > oscillation was involved. I installed a 33 ohm resistor, in series
> > > with the control grid lead, of the oscillator tube. The problem was
> > > cured.
> > >
> > >  It was my guess that 3.6 Mhz was a sub harmonic of the frequency of
> > > the undesired VHF parasitic oscillation, that was occurring,
> > > simultaneously, with the desired HF oscillation.
> > >
> > >  After that experience, I began installing parasitic suppressors, as
> > > a matter of routine.
> >
> > WOW ... The diagnosis sounds right: AT 3.6 mcs the parasite either
> > sucked so much energy from the intended tank circuit that it killed
> > oscillation or developed enough grid bias to do the same.
> >
> > Now that's one I've never had.
> >
> > Sometimes probing around with a frequency counter will turn up a
> > strong signal. Another old trick is touching things with the point of
> > a lead pencil (HV safety issue ...) which may kill a VHF oscillation
> > and suddenly make the circuit behave normally even if its off
> > frequency.
> >
> > I like to build in a test point for oscillator grid current -- like
> > use a 47k grid resistor but the ground end goes to a 1k resistor from
> > a test point to ground. A DVM will show the current which should
> > behave smoothly as you tune, a frequency counter may work there as
> > well.
> >
> > I too use parasitic suppressors as a matter of routine. The latest
> > tubes are excellent, they can often save you a stage in a receiver,
> > but you pay for the savings getting the thing tamed.
> >
> > Walt Hutchens
> > KJ4KV
> >
> > ______________________________________________________________
> > HBR mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/hbr
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:HBR at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

From waltah at earthlink.net  Thu Jan 16 22:01:06 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Thu, 16 Jan 2014 22:01:06 -0500
Subject: [HBR] Need help with noise
In-Reply-To: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
Message-ID: <399053522.20140116220106@earthlink.net>

Ian said:

> 6EJ7 RF amplifier. 6DJ8 first mixer. 3.075MHz bandpass filter
> (+-75kHz BW). 6EA8 second mixer. 455kHz mechanical filter (2.5kHz BW).
> 2x6EH7 IF amplifier. Beam deflection product detector. AF stage
> borrowed from the 75S3. Uses a PTO (actually Dubrow but very
> similar to Collins) for main tuning.

How are you doing the AGC?  The 6EJ7 is sharp cutoff, the 6EH7 is
semi-remote, so that's going to be a challenge.  Is it just the 6EJ7
RF/2 6EH7 that are on the AGC line?

It's A LOT easier to do AGC if all the tubes on the line are the same
or similar types. OR if most are the same type and one has a greater
cutoff point than the others and so contributes only a little to AGC
action but cannot be pushed into cutoff.

What's the 1st mixer circuit? With such a hot RF stage you need more
ability to handle large signals than gain; low noise is basically
pointless.

I assume the RF stage is fixed-tuned so the 2nd mixer sees 150 kcs of
the band.

What happens when you hook an antenna to the 1st mixer input? Or
(equivalent) pull the RF stage and hook a 'gimmick' from grid to
plate.

I'm thinking some stage is overloaded and/or the RF stage is running
at cutoff.

All receiver projects go through this phase:  The stages all work but the
receiver doesn't!

Walt Hutchens
KJ4KV


From ianmwilson73 at gmail.com  Thu Jan 16 22:36:59 2014
From: ianmwilson73 at gmail.com (Ian Wilson)
Date: Thu, 16 Jan 2014 19:36:59 -0800
Subject: [HBR] Need help with noise
In-Reply-To: <CA+uDY2Ska4mD0fVGK5SSpiwNNwcmriqZdxwQKsHC3kiKjCQUmw@mail.gmail.com>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<CA+uDY2Ska4mD0fVGK5SSpiwNNwcmriqZdxwQKsHC3kiKjCQUmw@mail.gmail.com>
Message-ID: <CAEz8jcTWcLA_KsG1DMcgfSpnwSn4OwXmpBmdMXv08YsAx1vwpw@mail.gmail.com>

The RF stage was touchy but improving the dressing of the leads to the
grid/plate coils/tuning cap seems to have tamed it.

Incidentally I don't intend to run the first stage at more than 3-5x gain;
it
is really there to act as a buffer between the preselector stages. The
6EH7/6EJ7 have good intermod characteristics so I am hoping that the
final front end will be pretty rugged.

73, ian K3IMW


On Thu, Jan 16, 2014 at 6:01 PM, Peter Bertini <radioconnection at gmail.com>wrote:

> Did you check the RF stage for parasitic oscillations? That might be a
> possibility if things seem squirrely.
>
> Pete
>
>
> On Thu, Jan 16, 2014 at 7:12 PM, Ian Wilson <ianmwilson73 at gmail.com>
> wrote:
>
> > Disclaimer: this is not an HBR. However, there are some receiver-builder
> > greats on this list so I hope this is OK.
> >
> > My receiver design is a sort-of 75S3C knockoff with newer tube types
> > and a number of other changes forced by available parts. It is a dual
> > conversion scheme with fixed 2nd IF of 455kHz.
> >
> > 6EJ7 RF amplifier. 6DJ8 first mixer. 3.075MHz bandpass filter
> > (+-75kHz BW). 6EA8 second mixer. 455kHz mechanical filter (2.5kHz BW).
> > 2x6EH7 IF amplifier. Beam deflection product detector. AF stage
> > borrowed from the 75S3. Uses a PTO (actually Dubrow but very
> > similar to Collins) for main tuning.
> >
> > Anyway. This works pretty well from some points of view. It is stable
> > enough and the birdies are under control. However, there is a great
> > deal of 'impulse' noise on the audio. This must be coming in through
> > the front end stages. If I short the IF strip input I can hear a faint
> > hiss.
> > If I short the first mixer input I can hear some band noise but well
> > below the level with an antenna connected.
> >
> > With a (very poor) antenna connected I can resolve CW and SSB
> > signals but both are very noisy. Listening on another receiver (with
> > a much better antenna), the same signals are way above the band
> > noise level.
> >
> > I have tried shielding the input tuned circuits (there is a bandswitched
> > pair of inductors scavenged from an HR-10, and a dual 100pF capacitor)
> > with no discernible effect.
> >
> > The audio bandwidth is not excessive (5kHz perhaps).
> >
> > Would welcome any suggestions. I have noticed before with this setup that
> > some receivers handle the conditions well, and some have lots of
> > apparent band noise.
> >
> > 73, ian K3IMW
> >
> >
> >
> >
> > On Sun, Jan 5, 2014 at 7:56 PM, Walt Hutchens <waltah at earthlink.net>
> > wrote:
> >
> > > Ron said:
> > >
> > > > After some had scratching, I began to suspect that a VHF parasitic
> > > > oscillation was involved. I installed a 33 ohm resistor, in series
> > > > with the control grid lead, of the oscillator tube. The problem was
> > > > cured.
> > > >
> > > >  It was my guess that 3.6 Mhz was a sub harmonic of the frequency of
> > > > the undesired VHF parasitic oscillation, that was occurring,
> > > > simultaneously, with the desired HF oscillation.
> > > >
> > > >  After that experience, I began installing parasitic suppressors, as
> > > > a matter of routine.
> > >
> > > WOW ... The diagnosis sounds right: AT 3.6 mcs the parasite either
> > > sucked so much energy from the intended tank circuit that it killed
> > > oscillation or developed enough grid bias to do the same.
> > >
> > > Now that's one I've never had.
> > >
> > > Sometimes probing around with a frequency counter will turn up a
> > > strong signal. Another old trick is touching things with the point of
> > > a lead pencil (HV safety issue ...) which may kill a VHF oscillation
> > > and suddenly make the circuit behave normally even if its off
> > > frequency.
> > >
> > > I like to build in a test point for oscillator grid current -- like
> > > use a 47k grid resistor but the ground end goes to a 1k resistor from
> > > a test point to ground. A DVM will show the current which should
> > > behave smoothly as you tune, a frequency counter may work there as
> > > well.
> > >
> > > I too use parasitic suppressors as a matter of routine. The latest
> > > tubes are excellent, they can often save you a stage in a receiver,
> > > but you pay for the savings getting the thing tamed.
> > >
> > > Walt Hutchens
> > > KJ4KV
> > >
> > > ______________________________________________________________
> > > HBR mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/hbr
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:HBR at mailman.qth.net
> > >
> > > This list hosted by: http://www.qsl.net
> > > Please help support this email list: http://www.qsl.net/donate.html
> > >
> > ______________________________________________________________
> > HBR mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/hbr
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:HBR at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

From ianmwilson73 at gmail.com  Thu Jan 16 22:52:45 2014
From: ianmwilson73 at gmail.com (Ian Wilson)
Date: Thu, 16 Jan 2014 19:52:45 -0800
Subject: [HBR] Need help with noise
In-Reply-To: <399053522.20140116220106@earthlink.net>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<399053522.20140116220106@earthlink.net>
Message-ID: <CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>

The two 6EH7s in the IF strip are AGC controlled.

The first mixer uses a 6DJ8 with the second triode as cathode follower
(a Pullen mixer, with the different gms of the two stages arranged via
different plate voltages on the two triodes).

The first mixer scheme uses crystals 100kHz apart (well, in the 75S3, it
did. My scheme will use a Si570 but at the moment a crystal oscillator
lets me cover 7.0 - 7.15MHz (actually more since the first IF bandpass
isn't very steep).

Moving the antenna to the 1st mixer input lets 40m BC through. So I guess
the front end selectivity is doing its job, wonder why I didn't think of
doing that.

I'll see if I can test whether the RF stage is behaving linearly but it
will be
a day or two before I have time to try this.

Thank you for the things to check, etc.

73, ian K3IMW



On Thu, Jan 16, 2014 at 7:01 PM, Walt Hutchens <waltah at earthlink.net> wrote:

> Ian said:
>
> > 6EJ7 RF amplifier. 6DJ8 first mixer. 3.075MHz bandpass filter
> > (+-75kHz BW). 6EA8 second mixer. 455kHz mechanical filter (2.5kHz BW).
> > 2x6EH7 IF amplifier. Beam deflection product detector. AF stage
> > borrowed from the 75S3. Uses a PTO (actually Dubrow but very
> > similar to Collins) for main tuning.
>
> How are you doing the AGC?  The 6EJ7 is sharp cutoff, the 6EH7 is
> semi-remote, so that's going to be a challenge.  Is it just the 6EJ7
> RF/2 6EH7 that are on the AGC line?
>
> It's A LOT easier to do AGC if all the tubes on the line are the same
> or similar types. OR if most are the same type and one has a greater
> cutoff point than the others and so contributes only a little to AGC
> action but cannot be pushed into cutoff.
>
> What's the 1st mixer circuit? With such a hot RF stage you need more
> ability to handle large signals than gain; low noise is basically
> pointless.
>
> I assume the RF stage is fixed-tuned so the 2nd mixer sees 150 kcs of
> the band.
>
> What happens when you hook an antenna to the 1st mixer input? Or
> (equivalent) pull the RF stage and hook a 'gimmick' from grid to
> plate.
>
> I'm thinking some stage is overloaded and/or the RF stage is running
> at cutoff.
>
> All receiver projects go through this phase:  The stages all work but the
> receiver doesn't!
>
> Walt Hutchens
> KJ4KV
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

From waltah at earthlink.net  Fri Jan 17 09:28:38 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Fri, 17 Jan 2014 09:28:38 -0500
Subject: [HBR] Need help with noise
In-Reply-To: <CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<399053522.20140116220106@earthlink.net>
	<CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
Message-ID: <1869367141.20140117092838@earthlink.net>

Ian said:

> The two 6EH7s in the IF strip are AGC controlled.

> The first mixer uses a 6DJ8 with the second triode as cathode follower
> (a Pullen mixer, with the different gms of the two stages arranged via
> different plate voltages on the two triodes).

This is likely the problem.

I once lived in an urban area where my full wave horizontal loop for
80M would deliver half a volt RMS at 75 ohms on an open circuit. Even
in rural places with less flat-out garbage in the ether there's too
much power coming from a resonant antenna for such a sensitive front
end.

One of my all-time favorite receivers is a seven-tube series filament
band imaging 80-40 set: 35W4 rectifier, 12AT7 mixer (signal push-pull,
injection push-pull, output single end) to a half lattice crystal
filter at 5500 kcs with a 12AU7 push-pull (Colpitts-derived)
oscillator driving the 12AT7 cathodes.

IF is two stages of 19JN8 sharp cutoff pentodes. Two plate detectors
deliver the audio and AGC signals. AGC is applied to the mixer as well
as the two IF stages; because of the low LO frequency this doesn't
pull the LO frequency significantly.

Note that there's very little gain -- just a triode mixer -- ahead of
the crystal 'knothole.' And that the push-pull mixer tends to cancel
distortion products so it's more linear on the signal path than a
single triode would be.

The antenna/mixer coil is a 1" toroid wound full of #24.

The gain that isn't there in the front end is made up in the (plate)
detector so the IF signals stay small -- fraction of a volt. All you
want there is enough to be sure of overcoming 1st IF noise at the
input and driving the AGC at the output.

In your set, the 6EH7 -- designed for TV IF service -- gives you a lot
of flexibility.

Ham signals on 40 were easily copied (at 8AM local) on this set with
no antenna -- the unshielded antenna coil and wiring were enough and
touching the high-z antenna terminal gave room-filling volume from a
3" speaker.

Gain is a non-issue for an HF set, at least below 20M. Low noise is
unimportant below 10M because there's so much noise coming with the
signal from the antenna. The challenge through 40M is the hatchet work
of getting rid of the off-channel signals before they drive something
into non-linearity. The mixer is the most likely victim and in my
opinion the Pullen has a kick me sign on it.

A great advantage of the W6TC designs is very high Q RF-mixer tuned
circuits -- maybe 150-200. These much reduce the amount of garbage
reaching the mixer. Those tiny HR-10 coils might have a Q of 50. The
greater the front end bandwidth the tougher the mixer has to be.

I once saw a speculation from some receiver designing ham about the
characteristics of an 811A as a mixer. He was kidding, but the point
was that the first requirement of an HF front end is robustness.

Things get a little harder for an all band receiver because 20-10 do
need some front end gain. The excellent G2DAF design uses a 6ES8
push-pull triode RF stage operating at unity gain but with gain
REDUCED when needed by the AGC so it's really just an AGC controlled
attenuator. The mixer is a 6DJ8 in push-pull -- there's your front end
gain. That's one way to do it.

For all-band service you pretty well have to gain control the RF stage
-- either manual or AGC. There's just too much change in the
conditions between 160 -> 40 and the higher bands.

I would rethink that front end.

Walt Hutchens
KJ4KV


From aaf-radio-1 at aafradio.org  Fri Jan 17 10:04:27 2014
From: aaf-radio-1 at aafradio.org (Mike Hanz)
Date: Fri, 17 Jan 2014 10:04:27 -0500
Subject: [HBR] Need help with noise
In-Reply-To: <1869367141.20140117092838@earthlink.net>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com><399053522.20140116220106@earthlink.net><CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
	<1869367141.20140117092838@earthlink.net>
Message-ID: <52D9467B.5080901@aafradio.org>

On 1/17/2014 9:28 AM, Walt Hutchens wrote:
> The mixer is the most likely victim and in my
> opinion the Pullen has a kick me sign on it.

I've never had a problem with getting the Pullen circuit to work well, 
but I've probably simply been lucky with component selection and 
voltages.  Just curious, Walt - have you ever thought about using the 
variable mu capability of a 6ES8 in a Pullen mixer with AGC?  Keats 
Pullen mentioned the possibility to me at a hamfest years ago but had no 
data on it.  Perhaps a balanced mixer using two 6ES8s to eliminate the 
even order harmonics and gain varied with AGC?  It would still need a 
6ES8 preselector in front like the G2DAF design, of course.

      Very 73,
  - Mike  KC4TOS



From whitebear1122 at comcast.net  Fri Jan 17 14:01:42 2014
From: whitebear1122 at comcast.net (whitebear1122 at comcast.net)
Date: Fri, 17 Jan 2014 19:01:42 +0000 (UTC)
Subject: [HBR] Believe it or not, I'm Working on the HBR :)
In-Reply-To: <52D56A7A.2070201@comcast.net>
Message-ID: <862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>



I know.? Willl wonders never cease?? With the bulk of my major 3 year ?radio sell off? in the rear view mirror (sold off 80% of my radios), I'm starting back up on the HBR project. 



After vacillating over the past 3 years between building a 17, 16, 11, 12, and 13, I've decided to build the HBR-13, not 13C but straight 13.? I read about Ted and others efforts with difficulty in getting the IF's to be regenerative.? The conclusion by the experts was that the centering of the raised RF subchassis changed things and ?had "something" to do with it but they could never put their finger on the absolute cause.? I have an HBR-16?and all three amplifiers easily go into? oscillation?on command, and I also have an HBR-13C that just doesn't go into oscillation. ? I'm going to build mine? with the dial offset on the left of the panel like the earlier HBR's. 



I never did find the Miller 1730 1800 Kc IF transformers so I've come up with two options for the transformer coupled first IF amplifier stage .? I found a set of BC-454 1415 Kc IF's plus I'm hoping to take delivery soon of a pair of Hallicrafters 1650 Kc IF's.? So I have the 1610 IF amplifier stage figured out. 



For the 100 Kc IF's, I have two options as well, as I've been able to find 2 1709's and 2 1710's over the past couple of years.? Those 4 transformers will cover the 100 Kc IF chain including the back to back first 100 Kc IF amp stage.? I also have a set of BC-453 85 Kc IF's that I may use.? I've been vacillating the past couple of nights over the 100 Kc IF design, wondering if I should make the 2nd 100 Kc IF using back to back transformers like the first back to back stage.? Ted Crosby talks about it in his Oct 1965 article.??I have enough BC-453 transformers to do the dual back to back IF's but not enough 1710 or 1709.? I would need one more 1710 or 1709 to do it with the Miller parts.? The BC-453 IF's are huge and?those back to back IF's take up alof of space. ?Hence the vacillating and layout changes .? 



I am laying out the mechanical design right now.?? I was planning for a 17" chassis, then tried for a 14" chassis.? Wow what a tight fit.? I'm back to the 17".? I've completed two full chassis mechanical layout drawings ?for a 14" and a 17" chassis, and darn if last night I decided to try one more.? I'm trying different layouts to optimize placement depending which and how many? 1610 Kc IF's and 100 Kc IF's I use, what sized chassis, what size cabinet.? Alot of variables. ? 



The front panel mechanical drawing is complete enough to start drilling the chassis front.? Just need to finish up the chassis top layout so I can drill, mill, and get building.? 



I've got an Eddystone dial that is roughly dimensioned on the front panel layout?but I won't drill until I complete the rest of the radio and have it working.? Then I can lay the clear plexiglass dummy ?panel up to the chassis and double and triple check the dimensioning.?? 



So that's where I am at moment.? Wish me luck.?? ? 



73, Scott WA9WFA 


From wrcromwell at gmail.com  Fri Jan 17 14:13:36 2014
From: wrcromwell at gmail.com (Bill Cromwell)
Date: Fri, 17 Jan 2014 14:13:36 -0500
Subject: [HBR] Believe it or not, I'm Working on the HBR :)
In-Reply-To: <862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
References: <862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
Message-ID: <52D980E0.5060202@gmail.com>

On 01/17/2014 02:01 PM, whitebear1122 at comcast.net wrote:
> ---snip------
>
>
> So that's where I am at moment.  Wish me luck.
>
>
>
> 73, Scott WA9WFA
>
>
Good luck Scott.

73,

Bill  KU8H

From sswhite at mchsi.com  Fri Jan 17 18:00:03 2014
From: sswhite at mchsi.com (Steve)
Date: Fri, 17 Jan 2014 17:00:03 -0600
Subject: [HBR] Believe it or not, I'm Working on the HBR :)
In-Reply-To: <862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
References: <52D56A7A.2070201@comcast.net>
	<862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
Message-ID: <83A83A9C339D4F089287BB0EE1931FBA@Ghz>

Scott

I am following what you are doing closely so that I can learn how to build
one of the HBR's myself...I am not as far along as you since I do not have
the IF figured out yet.   I have the 85Khz ones, they are all the same part
number too...Not sure if that is good or bad...I have some unknown 265Khz IF
transformers that I am trying to characterize with the specturm analyzer and
then modify them for 100Khz.  This is turning out to be more difficult than
I had thought it might be.  I am interested in CW only so want as narrow a
bandpass as I can reasonably get...I am not sure what the correct test
fixture for these might be.  I am using a 22k input resistor and a 100
resistor across the output of the transformer with no coupling caps.  Does
the collective wisdom of the group think this is a correct method???  I have
a nice HP sweep generator and a HP8590 Spectrum Analyzer.  No tracking
generator but I hope this will work this way..

Steve  NU0P


-----Original Message-----
From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
Behalf Of whitebear1122 at comcast.net
Sent: Friday, January 17, 2014 1:02 PM
To: HBR Receiver List
Subject: [HBR] Believe it or not, I'm Working on the HBR :)



I know.? Willl wonders never cease?? With the bulk of my major 3 year ?radio
sell off? in the rear view mirror (sold off 80% of my radios), I'm starting
back up on the HBR project. 



After vacillating over the past 3 years between building a 17, 16, 11, 12,
and 13, I've decided to build the HBR-13, not 13C but straight 13.? I read
about Ted and others efforts with difficulty in getting the IF's to be
regenerative.? The conclusion by the experts was that the centering of the
raised RF subchassis changed things and ?had "something" to do with it but
they could never put their finger on the absolute cause.? I have an
HBR-16?and all three amplifiers easily go into? oscillation?on command, and
I also have an HBR-13C that just doesn't go into oscillation. ? I'm going to
build mine? with the dial offset on the left of the panel like the earlier
HBR's. 



I never did find the Miller 1730 1800 Kc IF transformers so I've come up
with two options for the transformer coupled first IF amplifier stage .? I
found a set of BC-454 1415 Kc IF's plus I'm hoping to take delivery soon of
a pair of Hallicrafters 1650 Kc IF's.? So I have the 1610 IF amplifier stage
figured out. 



For the 100 Kc IF's, I have two options as well, as I've been able to find 2
1709's and 2 1710's over the past couple of years.? Those 4 transformers
will cover the 100 Kc IF chain including the back to back first 100 Kc IF
amp stage.? I also have a set of BC-453 85 Kc IF's that I may use.? I've
been vacillating the past couple of nights over the 100 Kc IF design,
wondering if I should make the 2nd 100 Kc IF using back to back transformers
like the first back to back stage.? Ted Crosby talks about it in his Oct
1965 article.??I have enough BC-453 transformers to do the dual back to back
IF's but not enough 1710 or 1709.? I would need one more 1710 or 1709 to do
it with the Miller parts.? The BC-453 IF's are huge and?those back to back
IF's take up alof of space. ?Hence the vacillating and layout changes .? 



I am laying out the mechanical design right now.?? I was planning for a 17"
chassis, then tried for a 14" chassis.? Wow what a tight fit.? I'm back to
the 17".? I've completed two full chassis mechanical layout drawings ?for a
14" and a 17" chassis, and darn if last night I decided to try one more.?
I'm trying different layouts to optimize placement depending which and how
many? 1610 Kc IF's and 100 Kc IF's I use, what sized chassis, what size
cabinet.? Alot of variables. ? 



The front panel mechanical drawing is complete enough to start drilling the
chassis front.? Just need to finish up the chassis top layout so I can
drill, mill, and get building.? 



I've got an Eddystone dial that is roughly dimensioned on the front panel
layout?but I won't drill until I complete the rest of the radio and have it
working.? Then I can lay the clear plexiglass dummy ?panel up to the chassis
and double and triple check the dimensioning.?? 



So that's where I am at moment.? Wish me luck.?? ? 



73, Scott WA9WFA 

______________________________________________________________
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From smithab11 at comcast.net  Fri Jan 17 18:16:15 2014
From: smithab11 at comcast.net (B. Smith)
Date: Fri, 17 Jan 2014 18:16:15 -0500
Subject: [HBR] Believe it or not, I'm Working on the HBR :)
In-Reply-To: <83A83A9C339D4F089287BB0EE1931FBA@Ghz>
References: <52D56A7A.2070201@comcast.net>	<862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
	<83A83A9C339D4F089287BB0EE1931FBA@Ghz>
Message-ID: <52D9B9BF.4000307@comcast.net>

I discussed testing the IF coils with a simple jig at:
http://k4che.com/HBR/IF%20Coil%20Pages%20and%20Photos/IF%20Coil%20Selection.htm

I would be interested in other methods .

k4che



On 1/17/2014 6:00 PM, Steve wrote:
> Scott
>
> I am following what you are doing closely so that I can learn how to build
> one of the HBR's myself...I am not as far along as you since I do not have
> the IF figured out yet.   I have the 85Khz ones, they are all the same part
> number too...Not sure if that is good or bad...I have some unknown 265Khz IF
> transformers that I am trying to characterize with the specturm analyzer and
> then modify them for 100Khz.  This is turning out to be more difficult than
> I had thought it might be.  I am interested in CW only so want as narrow a
> bandpass as I can reasonably get...I am not sure what the correct test
> fixture for these might be.  I am using a 22k input resistor and a 100
> resistor across the output of the transformer with no coupling caps.  Does
> the collective wisdom of the group think this is a correct method???  I have
> a nice HP sweep generator and a HP8590 Spectrum Analyzer.  No tracking
> generator but I hope this will work this way..
>
> Steve  NU0P
>
>
> -----Original Message-----
> From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
> Behalf Of whitebear1122 at comcast.net
> Sent: Friday, January 17, 2014 1:02 PM
> To: HBR Receiver List
> Subject: [HBR] Believe it or not, I'm Working on the HBR :)
>
>
>
> I know.  Willl wonders never cease?  With the bulk of my major 3 year  radio
> sell off  in the rear view mirror (sold off 80% of my radios), I'm starting
> back up on the HBR project.
>
>
>
> After vacillating over the past 3 years between building a 17, 16, 11, 12,
> and 13, I've decided to build the HBR-13, not 13C but straight 13.  I read
> about Ted and others efforts with difficulty in getting the IF's to be
> regenerative.  The conclusion by the experts was that the centering of the
> raised RF subchassis changed things and  had "something" to do with it but
> they could never put their finger on the absolute cause.  I have an
> HBR-16 and all three amplifiers easily go into  oscillation on command, and
> I also have an HBR-13C that just doesn't go into oscillation.   I'm going to
> build mine  with the dial offset on the left of the panel like the earlier
> HBR's.
>
>
>
> I never did find the Miller 1730 1800 Kc IF transformers so I've come up
> with two options for the transformer coupled first IF amplifier stage .  I
> found a set of BC-454 1415 Kc IF's plus I'm hoping to take delivery soon of
> a pair of Hallicrafters 1650 Kc IF's.  So I have the 1610 IF amplifier stage
> figured out.
>
>
>
> For the 100 Kc IF's, I have two options as well, as I've been able to find 2
> 1709's and 2 1710's over the past couple of years.  Those 4 transformers
> will cover the 100 Kc IF chain including the back to back first 100 Kc IF
> amp stage.  I also have a set of BC-453 85 Kc IF's that I may use.  I've
> been vacillating the past couple of nights over the 100 Kc IF design,
> wondering if I should make the 2nd 100 Kc IF using back to back transformers
> like the first back to back stage.  Ted Crosby talks about it in his Oct
> 1965 article.  I have enough BC-453 transformers to do the dual back to back
> IF's but not enough 1710 or 1709.  I would need one more 1710 or 1709 to do
> it with the Miller parts.  The BC-453 IF's are huge and those back to back
> IF's take up alof of space.  Hence the vacillating and layout changes .
>
>
>
> I am laying out the mechanical design right now.   I was planning for a 17"
> chassis, then tried for a 14" chassis.  Wow what a tight fit.  I'm back to
> the 17".  I've completed two full chassis mechanical layout drawings  for a
> 14" and a 17" chassis, and darn if last night I decided to try one more.
> I'm trying different layouts to optimize placement depending which and how
> many  1610 Kc IF's and 100 Kc IF's I use, what sized chassis, what size
> cabinet.  Alot of variables.
>
>
>
> The front panel mechanical drawing is complete enough to start drilling the
> chassis front.  Just need to finish up the chassis top layout so I can
> drill, mill, and get building.
>
>
>
> I've got an Eddystone dial that is roughly dimensioned on the front panel
> layout but I won't drill until I complete the rest of the radio and have it
> working.  Then I can lay the clear plexiglass dummy  panel up to the chassis
> and double and triple check the dimensioning.
>
>
>
> So that's where I am at moment.  Wish me luck.
>
>
>
> 73, Scott WA9WFA
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


From daileyservices at qwest.net  Fri Jan 17 18:34:08 2014
From: daileyservices at qwest.net (TC Dailey)
Date: Fri, 17 Jan 2014 16:34:08 -0700
Subject: [HBR] IF xfmrs
References: <52D56A7A.2070201@comcast.net><862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
	<83A83A9C339D4F089287BB0EE1931FBA@Ghz>
Message-ID: <9900B08BF0FD484BA8C473FF60D2671B@w0eaj>

I know we all like the 1700kc or 85kc variety, but I have several new 455kc 
IF cans.  They are in pairs (input / output), and were used in an 
electronics class kit-type setup with modules that one could plug in.  If 
anybody's interested, I'll count them up and make a package offer.  I've 
kept them, as I repair/restore lots of boatanchor radios and figured they'd 
make good spares, but never used but one.  Tom - W0EAJ - Denver 


---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com


From stutzt-allenk at att.net  Fri Jan 17 21:56:20 2014
From: stutzt-allenk at att.net (stutzt-allenk at att.net)
Date: Fri, 17 Jan 2014 18:56:20 -0800 (PST)
Subject: [HBR] Believe it or not, I'm Working on the HBR :)
In-Reply-To: <862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
References: <52D56A7A.2070201@comcast.net>
	<862744653.129638.1389985302417.JavaMail.root@sz0139a.emeryville.ca.mail.comcast.net>
Message-ID: <1390013780.70161.YahooMailNeo@web181205.mail.ne1.yahoo.com>

Best of luck.? I for one would love to see your layouts for the 17" chassis & front panel as that is the size I have and am planning on using (someday...).? 

Thanks,
Tom
AF6QA




>________________________________
>I am laying out the mechanical design right now.?? I was planning for a 17" chassis, then tried for a 14" chassis.? Wow what a tight fit.? I'm back to the 17".? I've completed two full chassis mechanical layout drawings ?for a 14" and a 17" chassis, and darn if last night I decided to try one more.? I'm trying different layouts to optimize placement depending which and how many? 1610 Kc IF's and 100 Kc IF's I use, what sized chassis, what size cabinet.? Alot of variables. ? 
>
>The front panel mechanical drawing is complete enough to start drilling the chassis front.? Just need to finish up the chassis top layout so I can drill, mill, and get building.? 
>

From ianmwilson73 at gmail.com  Sat Jan 18 18:39:45 2014
From: ianmwilson73 at gmail.com (Ian Wilson)
Date: Sat, 18 Jan 2014 15:39:45 -0800
Subject: [HBR] Need help with noise
In-Reply-To: <52D9467B.5080901@aafradio.org>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<399053522.20140116220106@earthlink.net>
	<CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
	<1869367141.20140117092838@earthlink.net>
	<52D9467B.5080901@aafradio.org>
Message-ID: <CAEz8jcQwxkn=DiCjHdf+DQW9hw0V3gka_8REV5m73pGm5KbW-A@mail.gmail.com>

I noticed somewhat belatedly that the HR-10 coils for 40 and 80m on
the plate side have a 2.2k resistor in parallel with each, presumably
to stop the original 6BZ6 from taking off. Removing this causes the
6EJ7 to become untamable, so I have some work to do there.

With the RF amp replaced by a 5pF capacitor (turning the two LCs
into a sort of double tuned preselector), the receiver behaves way
better, with what I regard as normal S/N for a not-very-narrow BW
system (the IF filter is 2.5kHz wide).

My intention for the RF amplifier was to provide a small amount of
gain (for poor antennas) with a manual RF gain control to act as an
attenuator for strong signals. I expect the 6EJ7 to have good intermod
characteristics, if I can get it tamed.

Will get back to this receiver in a week or two. I think it will work a lot
better if I can, indeed, rethink the front end.

73, ian K3IMW



On Fri, Jan 17, 2014 at 7:04 AM, Mike Hanz <aaf-radio-1 at aafradio.org> wrote:

> On 1/17/2014 9:28 AM, Walt Hutchens wrote:
>
>> The mixer is the most likely victim and in my
>> opinion the Pullen has a kick me sign on it.
>>
>
> I've never had a problem with getting the Pullen circuit to work well, but
> I've probably simply been lucky with component selection and voltages.
>  Just curious, Walt - have you ever thought about using the variable mu
> capability of a 6ES8 in a Pullen mixer with AGC?  Keats Pullen mentioned
> the possibility to me at a hamfest years ago but had no data on it.
>  Perhaps a balanced mixer using two 6ES8s to eliminate the even order
> harmonics and gain varied with AGC?  It would still need a 6ES8 preselector
> in front like the G2DAF design, of course.
>
>      Very 73,
>  - Mike  KC4TOS
>
>
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

From waltah at earthlink.net  Sat Jan 18 21:28:01 2014
From: waltah at earthlink.net (Walt Hutchens)
Date: Sat, 18 Jan 2014 21:28:01 -0500
Subject: [HBR] Need help with noise
In-Reply-To: <CAEz8jcQwxkn=DiCjHdf+DQW9hw0V3gka_8REV5m73pGm5KbW-A@mail.gmail.com>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<399053522.20140116220106@earthlink.net>
	<CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
	<1869367141.20140117092838@earthlink.net>
	<52D9467B.5080901@aafradio.org>
	<CAEz8jcQwxkn=DiCjHdf+DQW9hw0V3gka_8REV5m73pGm5KbW-A@mail.gmail.com>
Message-ID: <448461689.20140118212801@earthlink.net>

Ian said:

> With the RF amp replaced by a 5pF capacitor (turning the two LCs
> into a sort of double tuned preselector), the receiver behaves way
> better, with what I regard as normal S/N for a not-very-narrow BW
> system (the IF filter is 2.5kHz wide).

EXCELLENT!

The blind alleys I've slept in myself are easier to recognize than the
others ...

> My intention for the RF amplifier was to provide a small amount of
> gain (for poor antennas) with a manual RF gain control to act as an
> attenuator for strong signals. I expect the 6EJ7 to have good intermod
> characteristics, if I can get it tamed.

Why not a 6EH7 there? That eliminates any question of matching AGC
characteristics (with the IF stage tubes) and the 6EH7 is a
superlative large signal performer, especially at higher bias (AGC)
voltages. The gain is less than the 6EJ7 but that too is in the right
direction.

If the RF stage is fixed tuned (and must thus be broad) then much of
the gain reduction can be done by loading the tuned circuits as in the
HR-10. (Maybe a combination of loading and stagger-tuning to give a
sharper drop-off outside the band you want to cover.) If it's tunable,
then you want as high a Q as you can get (since it can't be high
enough to make tuning awkward) and gain reduction can be accomplished
with cathode bias on the tube and mismatching, perhaps by link
coupling to the two coils. Of course that complicates the
bandswitching for an all-band receiver.

Another variable is the 1st mixer: Since you have excess gain to play
with you could think about a lower gain mixer; maybe a 12AT7, maybe
even a 12AU7.

> Will get back to this receiver in a week or two. I think it will work a lot
> better if I can, indeed, rethink the front end.

It sounds like that's the only major issue.

Walt Hutchens


From ianmwilson73 at gmail.com  Mon Jan 27 12:05:29 2014
From: ianmwilson73 at gmail.com (Ian Wilson)
Date: Mon, 27 Jan 2014 09:05:29 -0800
Subject: [HBR] Need help with noise
In-Reply-To: <448461689.20140118212801@earthlink.net>
References: <CAEz8jcTF5kBGMNkGo8B_1Rp+F5j=Wn6ozokQ_Zh6skLD5nb8uw@mail.gmail.com>
	<399053522.20140116220106@earthlink.net>
	<CAEz8jcROHdiDXCGMZqZdnVqB83gU=J5vXSqrNz855krdPeW_3Q@mail.gmail.com>
	<1869367141.20140117092838@earthlink.net>
	<52D9467B.5080901@aafradio.org>
	<CAEz8jcQwxkn=DiCjHdf+DQW9hw0V3gka_8REV5m73pGm5KbW-A@mail.gmail.com>
	<448461689.20140118212801@earthlink.net>
Message-ID: <CAEz8jcQ4fpUOvrGWYtSYSxzVCvvjS0WGUNKeuDWfeTAAj3ubHw@mail.gmail.com>

There were 3 major problems, two of which had to do with the preselector/RF
amp stage: poor shielding between sections of the dual-gang tuning
capacitor,
and horrible layout around the RF stage (caused by an unforeseen change in
approach to the front end layout). Tackling these has stabilized the RF
stage
nicely. There may well be problems on higher bands so I need to improve
things
more, though. I have a 1k cathode resistor on the 6EH7 so this is not
running
flat out (will be adding a manual gain pot).

Another problem was caused by poor design in the coupling between the 2nd
mixer and the 455kHz mechanical filter (these are some distance apart). Some
circuit simulation work revealed an enormous amount of loss. Fixed now.

As a result there is now rather too much gain to run with no AGC with a few
feet of wire as an antenna. This is what I was expecting; I can modify the
gain
distribution later.

Still lots to do but the basic stuff seems to be working well now; thanks
again
for the help.

73, ian K3IMW



On Sat, Jan 18, 2014 at 6:28 PM, Walt Hutchens <waltah at earthlink.net> wrote:

> Ian said:
>
> > With the RF amp replaced by a 5pF capacitor (turning the two LCs
> > into a sort of double tuned preselector), the receiver behaves way
> > better, with what I regard as normal S/N for a not-very-narrow BW
> > system (the IF filter is 2.5kHz wide).
>
> EXCELLENT!
>
> The blind alleys I've slept in myself are easier to recognize than the
> others ...
>
> > My intention for the RF amplifier was to provide a small amount of
> > gain (for poor antennas) with a manual RF gain control to act as an
> > attenuator for strong signals. I expect the 6EJ7 to have good intermod
> > characteristics, if I can get it tamed.
>
> Why not a 6EH7 there? That eliminates any question of matching AGC
> characteristics (with the IF stage tubes) and the 6EH7 is a
> superlative large signal performer, especially at higher bias (AGC)
> voltages. The gain is less than the 6EJ7 but that too is in the right
> direction.
>
> If the RF stage is fixed tuned (and must thus be broad) then much of
> the gain reduction can be done by loading the tuned circuits as in the
> HR-10. (Maybe a combination of loading and stagger-tuning to give a
> sharper drop-off outside the band you want to cover.) If it's tunable,
> then you want as high a Q as you can get (since it can't be high
> enough to make tuning awkward) and gain reduction can be accomplished
> with cathode bias on the tube and mismatching, perhaps by link
> coupling to the two coils. Of course that complicates the
> bandswitching for an all-band receiver.
>
> Another variable is the 1st mixer: Since you have excess gain to play
> with you could think about a lower gain mixer; maybe a 12AT7, maybe
> even a 12AU7.
>
> > Will get back to this receiver in a week or two. I think it will work a
> lot
> > better if I can, indeed, rethink the front end.
>
> It sounds like that's the only major issue.
>
> Walt Hutchens
>
> ______________________________________________________________
> HBR mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hbr
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:HBR at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

