09-15-2013, 08:42 PM
Looking at the schematic, it appears that the volume control is not directly grounded to the chassis, but rather through a .01 uF cap. This is probably why you get a hum when you touch the shaft.
C16, connected to the slider of the volume control looks like it was a shielded cap with a ground connection. If you replaced it with a normal cap, it may be picking up hum. Is C16 near any line voltage AC wiring? There has to be some reason why the original cap had a grounded shield.
How are you doing with the sweep generator and FM alignments?
C16, connected to the slider of the volume control looks like it was a shielded cap with a ground connection. If you replaced it with a normal cap, it may be picking up hum. Is C16 near any line voltage AC wiring? There has to be some reason why the original cap had a grounded shield.
How are you doing with the sweep generator and FM alignments?
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