Quote:
Originally Posted by Kevin Kuehn
Sure seems to indicate a lack of gain in the tuner, which coincides with snow in picture. I wonder what would happen if you inject your alignment signal to a tube shield hovering over the local oscillator tube, so it's not grounded. That should capacity couple the signal so it's fed to the first IF stage. If that doesn't work I'd try through a capacitor to the first IF grid. [edit] forgot to mention you need to snip I think pin 1 on a 6J6 to capacity couple through a shield over a 6j6, which I think is the plate. Basically disables the oscillator and couples to the 2nd rf tube.
|
I'm rather worried about the 2 150 ohm resistors in the tuner's rf amp section, they are the same kind that were in the IF section, (all bad), and if they are as bad as this one, it's no wonder there is poor gain.
https://i.imgur.com/gBixele.jpg
there is a point E, that they suggest feeding in a signal into when alignment it REALLY bad, it's on the far end of the mixer coil stack in the tuner, and feeds into 1st IF.
I have found very few resistors bad above 1k ( just a few), but so far EVERY ONE, of the 150 ohms has been bad by 60%-190%, and there are 3 in the tuner
but I really dread pulling it out to replace them.