From maudie.widd at blueyonder.co.uk  Fri Mar 16 17:44:41 2007
From: maudie.widd at blueyonder.co.uk (Maudie)
Date: Fri Mar 16 18:19:55 2007
Subject: [HBR] I.F. information
Message-ID: <000801c7681c$b1a39810$69abc250@user>

Hello,
I am an ex radio service engineer who lost his sight in 1970 who has decided to build a double conversion receiver.  Due to my situation the reciever has to be a valve model.  I have found a good circuit diagram which I obtained from PW June 1962 but am have been unable   to locate a source where I can obtain I.F. transformers suitable for use with EF95 EF93 and 6BE6 valves.  The I.F. transformers I need are 1.6 Mcs chassis mounted types but I am sure I would be  able to adapt whatever.  I have almost all the other components except for these items and I don't think I could wind them myself that's if I could find the formers and cans.  Can you suggest a source.

Derek G4ESQ
From chnord at comcast.net  Fri Mar 16 18:30:10 2007
From: chnord at comcast.net (Carl Nord)
Date: Fri Mar 16 18:32:18 2007
Subject: [HBR] I.F. information
Message-ID: <031620072330.29987.45FB2882000479E50000752322155934140B9D0102080C@comcast.net>


 -------------- Original message ----------------------
From: "Maudie" <maudie.widd@blueyonder.co.uk>
> Hello,
> I am an ex radio service engineer who lost his sight in 1970 who has decided to 
> build a double conversion receiver.  Due to my situation the reciever has to be 
> a valve model.  I have found a good circuit diagram which I obtained from PW 
> June 1962 but am have been unable   to locate a source where I can obtain I.F. 
> transformers suitable for use with EF95 EF93 and 6BE6 valves.  The I.F. 
> transformers I need are 1.6 Mcs chassis mounted types but I am sure I would be  
> able to adapt whatever.  I have almost all the other components except for these 
> items and I don't think I could wind them myself that's if I could find the 
> formers and cans.  Can you suggest a source.
> 
> Derek G4ESQ
> ************************************
> Visit the HBR Receiver Web Site with over 100 pictures of receivers and 
> construction notes...... via http://www.qsl.net/k5bcq/ 
> there is also a mirror (faster response)at http://k5bcq.edebris.com/
>  
> 
> Retrieve reflector archived data via http://mailman.qth.net/mailman/listinfo/hbr
> 

From Hopperdhh at aol.com  Tue Mar 20 08:18:57 2007
From: Hopperdhh at aol.com (Hopperdhh@aol.com)
Date: Tue Mar 20 08:21:25 2007
Subject: [HBR] I.F. information
Message-ID: <c97.b05f428.33313941@aol.com>



Derek,
 
I once made some 1600 Kc IF transformers by unwinding 455 Kc units until they 
resonated at 1600.  This was quite tedious.
 
There are several places to find these transformers.  One example would be 
the old Aerotron VHF transceivers.  I just bought two of these at a hamfest last 
year for $5 each.  They each have 3 nice sized cans in them.  The cans 
measure 7/8 square by 1and 7/8 tall, not counting pins or the tuning screws.  These 
were overcoupled which I corrected by putting a shorted turn between the 
windings.  A couple of more sources are some old CB radios, and also the various 6 
meter transceivers like the Knight TR-106 and similar units made by Lafayette 
and others.  Some of these are showing up as parts radios.
 
Regards,
 
Dan K9WEK
 
 
In a message dated 3/16/2007 6:18:17 PM Eastern Standard Time, 
maudie.widd@blueyonder.co.uk writes:
Hello,
I am an ex radio service engineer who lost his sight in 1970 who has decided 
to build a double conversion receiver.  Due to my situation the reciever has 
to be a valve model.  I have found a good circuit diagram which I obtained from 
PW June 1962 but am have been unable   to locate a source where I can obtain 
I.F. transformers suitable for use with EF95 EF93 and 6BE6 valves.  The I.F. 
transformers I need are 1.6 Mcs chassis mounted types but I am sure I would be  
able to adapt whatever.  I have almost all the other components except for 
these items and I don't think I could wind them myself that's if I could find 
the formers and cans.  Can you suggest a source.

Derek G4ESQ



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From Hopperdhh at aol.com  Thu Mar 29 10:23:45 2007
From: Hopperdhh at aol.com (Hopperdhh@aol.com)
Date: Thu Mar 29 10:27:00 2007
Subject: [HBR] I.F. information
Message-ID: <bd5.ca2280d.333d3401@aol.com>

Derek,
 
I started to answer this when you first posted it, but I'm not sure if I did 
or not.
 
Some CB radios used 1600 KC IFs.  Also, some low cost 6 meter ham 
transceivers, and the Aerotron VHF FM transceivers.  I used two of the Aerotron IF units 
in a HBR that I have not finished yet.  They were overcoupled so I put a 
shorted turn between the windings which made them about right (critical coupling).
 
Years ago, I removed turns from 455 Kc cans to make them resonate at 1650.  
This probably lowers the Q somewhat from optimum, but they worked fine.  The 
coupling remained about right, but this was pretty tedious work.
 
Hope this helps,
 
Dan K9WEK
 
 
In a message dated 3/16/2007 6:18:17 PM Eastern Standard Time, 
maudie.widd@blueyonder.co.uk writes:

Hello,
I am an ex radio service engineer who lost his sight in 1970 who has decided 
to build a double conversion receiver.  Due to my situation the reciever has 
to be a valve model.  I have found a good circuit diagram which I obtained from 
PW June 1962 but am have been unable   to locate a source where I can obtain 
I.F. transformers suitable for use with EF95 EF93 and 6BE6 valves.  The I.F. 
transformers I need are 1.6 Mcs chassis mounted types but I am sure I would be  
able to adapt whatever.  I have almost all the other components except for 
these items and I don't think I could wind them myself that's if I could find 
the formers and cans.  Can you suggest a source.

Derek G4ESQ
************************************
Visit the HBR Receiver Web Site with over 100 pictures of receivers and 
construction notes...... via http://www.qsl.net/k5bcq/ 
there is also a mirror (faster response)at http://k5bcq.edebris.com/


Retrieve reflector archived data via 
http://mailman.qth.net/mailman/listinfo/hbr



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