[HBR] WTB coil forms

Wed Jan 1 09:11:33 EST 2014

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
>
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