Pierce tube oscillator not working. - UK Vintage Radio Repair and Restoration Discussion Forum

kostas_sv3ora · 15th Jan 2023, 2:52 pm

Here:-

http://qrp.gr/tubeosc/

is a Pierce low voltage tube crystal oscillator I have designed and it works fine on 6MHz but it does not work with a 452KHz crystal. I tried to remove the variable capacitor but still it does not oscillate. There are no other "resonant" elements to tweak.

I have also tried a 100k trimmer at the anode and a 1meg trimmer at the grid and varied them but I could not get it to oscillate.

I need the 452KHz so as to use it as a BFO to demodulate SSB signals on a Phillips BX620A driving it with heaters voltage greatly simplifies things.

Any ideas?

15th Jan 2023, 2:52 pm	#1
kostas_sv3ora Triode Join Date: Sep 2020 Location: Athens, Greece Posts: 21	Pierce tube oscillator not working. Here:- http://qrp.gr/tubeosc/ is a Pierce low voltage tube crystal oscillator I have designed and it works fine on 6MHz but it does not work with a 452KHz crystal. I tried to remove the variable capacitor but still it does not oscillate. There are no other "resonant" elements to tweak. I have also tried a 100k trimmer at the anode and a 1meg trimmer at the grid and varied them but I could not get it to oscillate. I need the 452KHz so as to use it as a BFO to demodulate SSB signals on a Phillips BX620A driving it with heaters voltage greatly simplifies things. Any ideas?