Ring mod circut...

[Eric at Svetlana Electron Devices]

>>The diodes are easy. Most any germanium type will work.
>>The transformers are the hard part. While almost any transformer that I
>>tried worked to some degree, I don't have any specs or types to try or look
>>for.

........allow me, Kev:

If you have driving circuits that can handle a 600-ohm load, any cheap
600-ohm-to-600-ohm telephone-type transformers will work. They
are RATED 300-3000 Hz, but actually go FAR beyond that.
The Mouser catalog has two pages of such transformers. Intended
for modems and other phone circuits.

If you want REALLY high fidelity: Try Thordarson 20A14s.
They are universal types, capable of three different primary-to
secondary ratios. They are high-impedance and can be driven
by almost anything (they were meant for tubes....) The higher
the voltage you drive them with, the better the diodes work.
Then, you can use even silicon diodes.....

They are part no. P-T20A14, $23.95 each from:
Antique Electronic Supply
6221 S. Maple
Tempe, Arizona 85283 USA
(602) 820-5411

Please spare me the complaints about their high prices
and large size--you want PERFORMANCE from that
diode ring modulator, you need use the RIGHT components.


Eric Barbour
Svetlana Electron Devices
Portola Valley CA USA