Minima QRP BFO and Mixer

I started with the BFO, put in an inductor 3,3 uH with one trimmer CT5 to minimum c, frequencies was 20,003 MHz, I tray to put in 2N7000 to connect the other trimmer CT4 butt F go 2-3 kHz lower without fet switched on. I try BA482 in serie to ground it only lower the frequency a few hundred Hz. Turning on the diod i found a value 2,2k to 4,7k will be fine, frequency is 19,995 MHz.

Dc is  T5:e = 5,6V T6:e = 5,2V it means 11 mA to the BFO. I winding the T3 6.5 turn trifilare on BN43–2402. Then time to do diode matching. see Diode... i think 2,2k to 12V is to mutch current 6mA, it take to long time to stabelesise.

The BFO gives 1,5Vp-p on C27 with no load. 600 mVp-p @ 50 ohm. I can now hare a IF 20MHz 1mV in to C38 also see 20MHz signal on osciloscope when tx and audio to mic amplifier.

Next its time for Bi-direction-amplifier.

Marry Christmas and a Good New Year, 

de SM4HNG Leif.