Printed electronic circuits made by Centralab and Sprague over 50 years ago! Looks like the forerunner to surface mount and integrated circuit design. They are just resistors and capacitors for the most part.
Been finding these in quite a few radios that were built in the 1950s and 1960s. So I am wondering how temperamental are these components? And should they be replaced when you recap a radio?
Wondering what the demand for these items would be as it would not be hard for me to make my own on a miniature PCB, add the components, 24 gauge wire connections, and an epoxy coating.
Personally, I have never experienced an issue with these and have never replaced one.
They are also known as an “Audet” or a “Couplate” depending on the manufacturer.
Considering that they contain relatively few components, it would not be difficult to duplicate the circuit.
You might find these references helpful. One is a cross reference to the Centralab part number, the second shows the schematics of the innards of the module.
I got those files too. Thanks for pointing them out to the rest of the membership. Interestingly enough, they came up with a few more circuits and I was able to find these files too, but it took a lot of digging. Never had an issue with them as well but you are right in that they would be easy to duplicate if a replacement were ever needed.
When you read about the construction techniques that were used to make these, you would think this was an inspiration for printed circuit boards, integrated circuits and surface mount type technology we use today. Amazing how these are all linked together in some form of synergy.
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