[Collins] Seeking 75S-3B T7 audio output transformer.

[Dr. Gerald N. Johnson]

On Sun, 2009-02-22 at 10:17 -0800, Robert Jefferis wrote:
> Hello to the list:
> 
> My 75S-3B went sneakers up. I have traced the problem to T7, Collins P/ 
> N 667-0302-000. Are there any replacements available out there? Thanks.
> 
> Bob, KF6BC 
>   
Google shows a universal long term want, from individuals to the
government. It also fits KWM-2 and 51S-1().

Hammond shows a universal that might work, but it does not have the
anti-vox and headphone outputs directly.

http://www.harbachelectronics.com/_mgxftp/pwdamateur/PWDAMATEURC.PDF may
be able to make one. They have the formula from Peter W. Dahl, but no
price in the price list.

http://www.therfshop.com/catalog/hamtrans011404.htm shows one for $125.

Most any 5 tube AC/DC radio has one that will drive the speaker but not
the antivox and head phone (500 ohm) outputs. However a tiny 500 ohm to
speaker transformer for transistors would fill that need, since both
those are low power loads.

Looks like the Hammond universal 3 or 5 watt for the 2500 ohm to 4 ohm
transformation 125A or 125B (better match to the mounting holes) and a
tiny Tamura model MET-35 or Xicon 42TL001-RC or 42TM001-RC or 42TM026-RC
or 42TU400-RC. Mouser catalog numbers 546-125A, 546-125B, and 838-
MET-35. The rest are already Mouser catalog numbers.

Clearly there's a market niche that needs filling.

Be sure the output tube plate to ground capacitor is not the trouble.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer