From mmarris at notecraft.com  Tue Jun  2 12:04:28 2015
From: mmarris at notecraft.com (Martin Marris)
Date: Tue, 2 Jun 2015 12:04:28 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>
Message-ID: <002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>

Thanks Brian. 

I've ordered those back issues -- sounds very interesting.

I've built a couple of regens in the past few years. The first one was an
ARRL-designed "three transistor" Novice set from 1968 which works quite
well, considering its relative simplicity. The other one is under
construction at the moment. It started out as an attempt to design a
portable regenerative set for use while hiking, but quickly morphed into
something more elaborate, with hopes of building a "high performance"
regenerative receiver using design tips from the 1920s and'30s. It uses
subminiature, battery-powered 1AD4 pentode tubes (about the size of a
fingertip). The current build has five tubes in four stages: RF amp,
regenerative detector, AF amp and switchable CW audio filter. It is the
first receiver that I can claim to have "designed" myself rather than
building from a kit or a published design. However, to say I did it "myself"
is a big exaggeration: I got masses of advice from the Elmers over on eham,
and several times was saved from making embarrassing mistakes!

You can read about it here:
http://www.eham.net/ehamforum/smf/index.php/topic,103101.0.html.

Best,

Martin

-----Original Message-----
From: HBR [mailto:hbr-bounces at mailman.qth.net] On Behalf Of Brian Burns
Sent: Saturday, May 30, 2015 16:28
To: 'HBR Receiver List'
Subject: [HBR] Regenerative communications receiver

Hello All,

 

Since things are quiet on the HBR list, and Kees says that discussions of
other receivers are Ok, I thought that I would mention an interesting
regenerative that I've run across in Electric Radio.

Vernon Yeich, KB3RQE, wrote a couple of construction articles, first in ER
#227 and then in ER #241. He has followed those up with an article in ER
#301 entitled "A CW Receiver With a Double Tuned Regenerative Loop", with a
number of changes to the original design. All these back issues are
currently available from Electric Radio.

I certainly don't understand all I know about this radio, but it looks like
Vernon has attempted to incorporate some of the various refinements that
hams were coming up with at the end of the regenerative era, say the
beginning of WWII. He quotes some very impressive selectivity numbers, and
the design has some features not normally found in a regen.

Cheers,

Brian

 

 

 



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From brianburns1066 at gmail.com  Tue Jun  2 17:08:57 2015
From: brianburns1066 at gmail.com (Brian Burns)
Date: Tue, 2 Jun 2015 14:08:57 -0700
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>
	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>
Message-ID: <CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>

Hello Martin,

I ran across that thread on eham while idling away Sunday morning a week
ago. I posted a link to it on the regenerx forum, a Yahoo group of
regenerative receiver enthusiasts. A good group of very well informed guys,
by the way. No less than Dave Newkirk, "Mr. Regen", posts to it, and Gary,
"Mr. Regenerodyne" is the moderator.

I've not read through the thread as yet---lots of stuff there---but it's
high on my priority list.

How do you find working with subminiatures? They look awfully small and
fragile.

I just today received the two back issues of ER with Vernon's original
construction articles on his receiver. I'm going to re-draw the schematic,
and see what I can learn from it.

Cheers,

Brian

On Tue, Jun 2, 2015 at 9:04 AM, Martin Marris <mmarris at notecraft.com> wrote:

> Thanks Brian.
>
> I've ordered those back issues -- sounds very interesting.
>
> I've built a couple of regens in the past few years. The first one was an
> ARRL-designed "three transistor" Novice set from 1968 which works quite
> well, considering its relative simplicity. The other one is under
> construction at the moment. It started out as an attempt to design a
> portable regenerative set for use while hiking, but quickly morphed into
> something more elaborate, with hopes of building a "high performance"
> regenerative receiver using design tips from the 1920s and'30s. It uses
> subminiature, battery-powered 1AD4 pentode tubes (about the size of a
> fingertip). The current build has five tubes in four stages: RF amp,
> regenerative detector, AF amp and switchable CW audio filter. It is the
> first receiver that I can claim to have "designed" myself rather than
> building from a kit or a published design. However, to say I did it
> "myself"
> is a big exaggeration: I got masses of advice from the Elmers over on eham,
> and several times was saved from making embarrassing mistakes!
>
> You can read about it here:
> http://www.eham.net/ehamforum/smf/index.php/topic,103101.0.html.
>
> Best,
>
> Martin
>
> -----Original Message-----
> From: HBR [mailto:hbr-bounces at mailman.qth.net] On Behalf Of Brian Burns
> Sent: Saturday, May 30, 2015 16:28
> To: 'HBR Receiver List'
> Subject: [HBR] Regenerative communications receiver
>
> Hello All,
>
>
>
> Since things are quiet on the HBR list, and Kees says that discussions of
> other receivers are Ok, I thought that I would mention an interesting
> regenerative that I've run across in Electric Radio.
>
> Vernon Yeich, KB3RQE, wrote a couple of construction articles, first in ER
> #227 and then in ER #241. He has followed those up with an article in ER
> #301 entitled "A CW Receiver With a Double Tuned Regenerative Loop", with a
> number of changes to the original design. All these back issues are
> currently available from Electric Radio.
>
> I certainly don't understand all I know about this radio, but it looks like
> Vernon has attempted to incorporate some of the various refinements that
> hams were coming up with at the end of the regenerative era, say the
> beginning of WWII. He quotes some very impressive selectivity numbers, and
> the design has some features not normally found in a regen.
>
> Cheers,
>
> Brian
>
>
>
>
>
>
>
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> http://www.avast.com
> ______________________________________________________________
> 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 mmarris at notecraft.com  Tue Jun  2 18:00:03 2015
From: mmarris at notecraft.com (Martin Marris)
Date: Tue, 2 Jun 2015 18:00:03 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>
	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>
Message-ID: <001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>

>>How do you find working with subminiatures? They look awfully small and
fragile.<<

It might seem that way, but it's the opposite. They were used at the
tail-end of the tube era in high-reliability situations such as missile
guidance systems (inside missile nose cones) or high-altitude aircraft gear.
You can subject them to the sort of vibration and other stresses that larger
tubes cannot handle. See, for instance,
http://frank.pocnet.net/other/Sylvania/GuidedMissileTubes.pdf (this may be
slow to load).

When using them in homebrew gear, you can wire them into the circuit much
like transistors because they have long, flexible leads. The 1AD4s I am
using are cheap (about $2 each from some suppliers) and abundantly
available.

I took a break during writing this email to put a 1AD4 on the hard-tile
kitchen floor, and then stepped on it, putting my entire weight on the tube.
Nothing happened. I've never tried to do that with a conventional, larger
tube -- maybe it would survive too, but I'm not so sure.

A sub-set of these tubes was designated as "reliable" by the U.S. military,
meaning, actually, almost indestructible. The Raytheon catalogue for
"reliable" tubes has pages and pages of the "torture tests" that these tubes
went through before being certified as "reliable."

Strange but true; and quickly eclipsed by solid-state.

Martin



From brianburns1066 at gmail.com  Tue Jun  2 19:30:43 2015
From: brianburns1066 at gmail.com (Brian Burns)
Date: Tue, 2 Jun 2015 16:30:43 -0700
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>
	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>
	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>
	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>
Message-ID: <CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com>

Hello Martin,

How about substituting them for "peanut tubes" ? I'm planning to build a
battery regen from the Feb.1940 issue of QST that specifies 1T4's, for
instance.

I would expect that power requirements would be less, and high frequency
performance better too, but what do I know (;->)...

Cheers,

Brian

On Tue, Jun 2, 2015 at 3:00 PM, Martin Marris <mmarris at notecraft.com> wrote:

> >>How do you find working with subminiatures? They look awfully small and
> fragile.<<
>
> It might seem that way, but it's the opposite. They were used at the
> tail-end of the tube era in high-reliability situations such as missile
> guidance systems (inside missile nose cones) or high-altitude aircraft
> gear.
> You can subject them to the sort of vibration and other stresses that
> larger
> tubes cannot handle. See, for instance,
> http://frank.pocnet.net/other/Sylvania/GuidedMissileTubes.pdf (this may be
> slow to load).
>
> When using them in homebrew gear, you can wire them into the circuit much
> like transistors because they have long, flexible leads. The 1AD4s I am
> using are cheap (about $2 each from some suppliers) and abundantly
> available.
>
> I took a break during writing this email to put a 1AD4 on the hard-tile
> kitchen floor, and then stepped on it, putting my entire weight on the
> tube.
> Nothing happened. I've never tried to do that with a conventional, larger
> tube -- maybe it would survive too, but I'm not so sure.
>
> A sub-set of these tubes was designated as "reliable" by the U.S. military,
> meaning, actually, almost indestructible. The Raytheon catalogue for
> "reliable" tubes has pages and pages of the "torture tests" that these
> tubes
> went through before being certified as "reliable."
>
> Strange but true; and quickly eclipsed by solid-state.
>
> Martin
>
>
> ______________________________________________________________
> 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 mmarris at notecraft.com  Tue Jun  2 20:13:20 2015
From: mmarris at notecraft.com (Martin Marris)
Date: Tue, 2 Jun 2015 20:13:20 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>
	<CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com>
Message-ID: <001801d09d92$19541030$4bfc3090$@notecraft.com>

>> I would expect that power requirements would be less, and high frequency
performance better too, but what do I know (;->)...<<

Power consumption is low, sometimes much lower than conventional tubes. I
just ordered a bunch of 6418 pentodes whose filaments draw only 10mA!! Low
enough to run for ages on a single AA battery.

But there are compromises. The above-cited 6418 has a transconductance of
only 200-300umos, for instance. It can be a challenge to get usable
performance out of such tubes, especially if (like me) you stick to the
directly heated types. The cathode types are better, but their power
consumption is much higher and at that point you have to wonder, why bother
using these small tubes in that case?

Best,

Martin



From wrcromwell at gmail.com  Tue Jun  2 21:34:58 2015
From: wrcromwell at gmail.com (Bill Cromwell)
Date: Tue, 02 Jun 2015 21:34:58 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <001801d09d92$19541030$4bfc3090$@notecraft.com>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>	<CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com>
	<001801d09d92$19541030$4bfc3090$@notecraft.com>
Message-ID: <556E59C2.5090307@gmail.com>

Hi,

Some of those tubes were used in proximity fuses for anti-aircraft 
artillery shells! That doesn't sound fragile to me.

73,

Bill  KU8H

From radio at daileyservices.com  Wed Jun  3 00:11:22 2015
From: radio at daileyservices.com (radio at daileyservices.com)
Date: Tue, 2 Jun 2015 22:11:22 -0600
Subject: [HBR] Regenerative communications receiver
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>	<CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com><001801d09d92$19541030$4bfc3090$@notecraft.com>
	<556E59C2.5090307@gmail.com>
Message-ID: <07606F514E094DCFB8ACEF758396F573@w0eaj>

They were used in "VT" ammunition.. typically, VT-frag and VT-non frag. 
Essentially an oscillator that when approaching a metallic object went off 
freq, and shazzam.. or at least that's how it was explained to me.

Tom - USN - former RMC.... and in the sordid daze of my junior-sailorship... 
the 1st. Loader on a 3"-.50 dual mount.

----- Original Message ----- 
From: "Bill Cromwell" <wrcromwell at gmail.com>
To: <hbr at mailman.qth.net>
Sent: Tuesday, June 02, 2015 7:34 PM
Subject: Re: [HBR] Regenerative communications receiver


> Hi,
>
> Some of those tubes were used in proximity fuses for anti-aircraft 
> artillery shells! That doesn't sound fragile to me.
>
> 73,
>
> Bill  KU8H
> ______________________________________________________________
> 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
> 


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From waltah at earthlink.net  Wed Jun  3 07:39:31 2015
From: waltah at earthlink.net (Walt Hutchens)
Date: Wed, 3 Jun 2015 07:39:31 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <07606F514E094DCFB8ACEF758396F573@w0eaj>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>
	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>
	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>
	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>
	<CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com><001801d09d92$19541030$4bfc3090$@notecraft.com>
	<556E59C2.5090307@gmail.com>
	<07606F514E094DCFB8ACEF758396F573@w0eaj>
Message-ID: <969715785.20150603073931@earthlink.net>

Radio said:

> They were used in "VT" ammunition.. typically, VT-frag and VT-non frag.
> Essentially an oscillator that when approaching a metallic object went off
> freq, and shazzam.. or at least that's how it was explained to me.

Yep. A VHF oscillator that also served as an oscillating detector
could sense nearby metal (Doppler effect from reflected wave caused
audio variation in the plate current) and would then trigger a
thyratron. Four subminiature tubes but these tubes were developed
specifically for this application -- thousands of G's acceleration and
a useful life of seconds! -- and weren't used for anything else.

Next to the atom bomb probably the most important American technical
advance of WW II.

There's a good Wiki article at:

https://en.wikipedia.org/wiki/Proximity_fuze

Subminiature receiving tubes are useful for the home constructor
mainly in battery operated gear. Once you get into indirectly heated
tubes the advantage of having two (or more) active devices in one
envelope gives the nod to miniature tubes for most applications.
Additionally, driven by the TV market miniature tube development went
beyond where subminatures quit so there are better tubes for many
jobs.

Subminiatures are easy enough to use for one or two tube designs where
the size payoff is small; once you get to more complex gear the wiring
technique and need for subminiature transformers, tuning caps, etc. is
a real challenge. But they were heavily used by the military in the
late 50's and 60's. Emergency sets for downed pilots, handy-talky
PRC-6, the backpack PRC 8-9-10 sets, etc.

Consider the size of the ~1950 SRR-11/12/13 sets: Just about as bulky
as any other communications receiver of the day, even though
subminiature tubes were used throughout.

They may be somewhat less fragile than miniatures, however I once
dumped a small box of subminiatures on a tile floor and about 1/3 of
them broke.

Walt
KJ4KV


From mmarris at notecraft.com  Wed Jun  3 08:04:42 2015
From: mmarris at notecraft.com (Martin Marris)
Date: Wed, 3 Jun 2015 08:04:42 -0400
Subject: [HBR] Regenerative communications receiver
In-Reply-To: <969715785.20150603073931@earthlink.net>
References: <!&!AAAAAAAAAAAYAAAAAAAAAO9WiXwKTRJMveKqmcXf97/CgAAAEAAAAGexu5uCr9ZPk8FDlr7HHioBAAAAAA==@lessonsinlutherie.com>	<002301d09d4d$cfaf28f0$6f0d7ad0$@notecraft.com>	<CAMNk5SrphvKcY4552Drt-br3ixiknf3CWDsMBXVpeqAUi32NYw@mail.gmail.com>	<001701d09d7f$7aa6bee0$6ff43ca0$@notecraft.com>	<CAMNk5So7jW+6zy3-SNNNDfF6HYmMh7er43tx5AEBLLKKe=SzKw@mail.gmail.com><001801d09d92$19541030$4bfc3090$@notecraft.com>	<556E59C2.5090307@gmail.com>	<07606F514E094DCFB8ACEF758396F573@w0eaj>
	<969715785.20150603073931@earthlink.net>
Message-ID: <001001d09df5$79c709a0$6d551ce0$@notecraft.com>

>>There's a good Wiki article at:
https://en.wikipedia.org/wiki/Proximity_fuze
<<

Thank you. That article is really interesting in describing the circuit,
which used subminiature tubes. Basically:
--An oscillator that transmitted a signal.
--An autodyne detector that received any reflected signal.
--Because of the high relative speed between the shell/bomb and the target,
the reflected signal would move rapidly in and out of phase with the
transmitted signal.
--These rapid phase shifts created an audio tone of 200Hz-800Hz.
--The audio was sent through a bandpass filter tuned to this tone.
--If the tone was present, it triggered a final thyratron tube and, "boom."

I'd love to see the bandpass filter circuit they used! I've just spent a
certain amount of time building a subminiature-tube CW bandpass filter with
a center frequency of 650Hz. I bet their circuit was a lot better than my
improvisation.

It's also amazing how large the proximity-fuze industry was: something like
$1 billion worth, during the course of the war. The price fell from $732
each, to $18 by the end of the war.

Martin



