[Collins] Universal Service Co. Product detector

[Jim Brannigan]

Al,
I don't have specific information on that product detector, but did install
a product detector in a 75A3 that mimicked the Universal.

The product detector plugged into the FM socket and derived filament and
plate voltage from the Receiver.  In the FM position, 455 IF signal is fed
to the product detector and demodulated audio fed back into the Receiver
audio chain.  The Receiver BFO is not used.  The BFO in the Universal
supplies +/- 455 kc injection voltage for the product detector.  A long
shaft extends through the front panel (in place of the Collins logo) and is
used to adjust the BFO.

There should be two tubes in the Universal.  A BFO and a product detector.
If you look at the tube types, a Handbook of that era (mid 1950's) will have
schematics that are close.

I hopes this helps.

Jim


Subject: [Collins] Universal Service Co. Product detector


> I have a  75A2 equipped with this commercial product detector model
> A2-3.
>
> Would anyone on the list have any information/schematic for the unit,
> and how it operates with the receiver.
>
> Thanks,
>
> Al Santangelo  VE3 AJM