Just asked what was wrong then I scroll down........
Run set with NO signal. Should get a strong high contrast snow
made of dots not streaks. Also a loud waterfall from the audio.
Turn channels. You should get strong static crashes between
channels as the contacts make/break. If you dont its
in the IF. DO NOT TWEAK IF COILS ! Even if it fixed it
you would be just covering up a failed component. Its not
normal drift that much.
If you get the good snow and strong crashes look to the tuner
tubes next. Do not trust a tube checker. Sub in known good
tubes of a brand name. If you dont need tubes in the end all
the tubes are common. 6HA5 used in Zenith from abt 1960 to
the end. 6BZ6, 6EH7, 6EJ7 all used in Zenith and many others.
Start with that.......
73 Zeno
