[Milsurplus] Repair of RF transformers

[Kenneth G. Gordon]

On 5 Oct 2018 at 13:54, Jim Whartenby wrote:

> 
> I see that this message never made it through the reflector, I guess because of the two photo 
> attachments.

Yes. We are limited to no more than 250 KB for file sizes on the reflector.
  
> I have a few photos explaining how to disassemble the SRR-13 / FRR-23 RF transformers 
> without breaking anything.  This allows the burnt winding to be replaced and the transformer to 
> be reassembled and put back into service.  If there is any interest, send a request off reflector 
> and I'll send the photos.

Please send them to me. I need them.

> Back to original note:
> 
> Replacement cranks can be made if you are handy, see:
> 
> 
> http://www.roveroresearch.info/home/boatanchor-radios/srr13/srr-13a---switch-arms/crank-arms

Or see them here too:

http://www.w7ekb.com/glowbugs/Military/SRR_radios.html

> Reworking the transformers requires some patience, a heat gun to soften the old epoxy and 
> some small tools to dig the softened epoxy out of the forms.  All can be done without breaking 
> anything so that the repaired transformer can be reassembled and appear to be as new.

This is super! When I repaired some transformers, I had to break the outer "case". They 
work OK, but sure don't look like new either. Your method will certainly help with this.

>  I have 
> a few old transformers if some need replacement parts.

Heh! I even have some new, never used ones. Trouble is, none are those I need. :-(

> I have found that there are really only two types of RF transformers: Oscillator and Amplifier.  All 
> amplifier transformers are electrically the same if they are of the same frequency range.  
> Physically they are keyed to fit the particular module and a small Swiss file will add a new notch 
> so that the transformer can be rotated to the proper orientation when installed in a different 
> module.

Kewel!

> See attachments, sorry if the size is a bit big for some if they don't have high speed internet 
> connection.  I can send s few more photos if there is any interest.

I would love to get any photos you have, Jim, and thanks.

Ken W7EKB