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Old 30th Aug 2009, 9:27 pm   #20
Dillen_de
Tetrode
 
Join Date: Jun 2007
Location: Copenhagen, Denmark
Posts: 62
Default Re: FM tuning drift - any ideas?

What a useful thread !

I have the exact same type of set on the bench here today.
It has the exact same fault - Tuning drift within the first couple of minutes.
But for the exact opposite reason in that the output valve cathode resistor has gone high in value.
It's the original resistor, solder joints were untouched etc. but for a 390 ohm
resistor, the measured value of 590 ohms (out of circuit) is way too high.
A new resistor of correct value cured the thing.
Obviously a weak point in these sets.

Martin
Dillen_de is offline