Friday, March 25, 2011

ECC82 Downconverter

I bough a spare ECC82 valve when I built the ECC82 regen receiver, already tried a valve VFO (worked), now decided to tryout a valve down converter as a first test to a tube direct conversion receiver.

Basically one half of the ECC82 is running as vfo then there's a single balanced mixer and will be an audio amplifier using the other half of the ECC82.
Interesting thing is that this circuit worked first time, I even forget to count the turns in the mixer core, the rfc was the first coil I found from an old PSU and the mixer output termination was the first small cap I found...
Signal out is not much but hell what do you expect from a lousy mixer made from a binocular core and 2 diodes and 4m of cable laying in the floor working as antenna...

The oscillator was running at 6.7Mhz and I was listening on 365Khz so one of the received frequencies was 7.067Mhz... I promise a schematic soon.

Add: here is the schematic used:

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