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Old 06-27-2017, 07:13 PM
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duodiode duodiode is offline
Duodiode
 
Join Date: Feb 2016
Location: Gold Coast, Queensland, Australia
Posts: 14
Working at last!

I've got it going! The lack of R.F. turned out to be due to two faults. One was the output coupling capacitor inside the turret tuner section had broken loose from the valve pin. The other was that the attenuator control was burned out, probably due to the output being accidentally connected to the B+ of a TV. I had to use an ordinary carbon potentiometer, which is of course less than ideal at R.F. As I figured, the picture is black bars on a white background, so not much good for convergence!
I still have a slight problem though, some slight vertical jitter, caused by some instability in the vertical synch generator which is a blocking oscillator synched to the mains. I've replaced all the capacitors again, and the valve, but no difference. Interestingly, I replaced a capacitor and the problem vanished, - for 15 minutes, but then returned. I think I'll call it a day. It is still quite usable. Thanks for your replies.

Cheers, Stuart
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