Zenith 10S690 Volume Control Issues

[vortalexfan]

Originally Posted by old_coot88

Have you tried Deoxit'ing the switch yet?

Yes I have, 3 times and it hasn't made a difference, if anything its made it worse.

[old_coot88]

To jumper the switch, just trace the wiring. Trace it from where the signal wire exits the 2nd IF can and goes to the switch. And trace from C11 to the switch. Put the jumper across the appropriate two lugs.

If perchance you don't plan on using the phono, just leave the jumper in place.

[vortalexfan]

Originally Posted by old_coot88

To jumper the switch, just trace the wiring. Trace it from where the signal wire exits the 2nd IF can and goes to the switch. And trace from C11 to the switch. Put the jumper across the appropriate two lugs.

If perchance you don't plan on using the phono, just leave the jumper in place.

OK, thanks, I'm assuming the lugs I'm jumping are on the switch itself?

I think it is definitely the switch because I'm not getting anything out of radio when I touch the Grid Cap of the 6F5G Audio Amp tube unless I jiggle the switch several times, and even then the hum from touching the grid cap of the 6F5G tube goes away after awhile.

[vortalexfan]

Originally Posted by old_coot88

To jumper the switch, just trace the wiring. Trace it from where the signal wire exits the 2nd IF can and goes to the switch. And trace from C11 to the switch. Put the jumper across the appropriate two lugs.

If perchance you don't plan on using the phono, just leave the jumper in place.

I think I could probably find a replacement switch over at Mouser or Digikey.

Its just a standard 6 Lug SPDT Switch.

In fact here it is on Mouser. https://www.mouser.com/ProductDetail...6%2FVdLw%3D%3D

[old_coot88]

Dude, I gotta apologize. Been giving you bad info. Come to find the switching is done on the downstream side of C11, not on the upstream as in previous sketch.

Thus to jumper the switch, the wires you would trace would be:

1.) from the top lug of volume control to the switch.

2.) from the downstream side of C11 to the switch.

Jumper would go on the appropriate two lugs of the switch.

Damn, sorry for the screwup

[vortalexfan]

Originally Posted by old_coot88

Dude, I gotta apologize. Been giving you bad info. Come to find the switching is done on the downstream side of C11, not on the upstream as in previous sketch.

Thus to jumper the switch, the wires you would trace would be:

1.) from the top lug of volume control to the switch.

2.) from the downstream side of C11 to the switch.

Jumper would go on the appropriate two lugs of the switch.

Damn, sorry for the screwup

Its ok, so I'll just jump the switch that way.

[old_coot88]

Turns out there's an obscure little subnote to the main schematic, showing the radio/phono switching diagram. It's difficult to decipher, but shows the switch as DPDT (double pole/double throw), with the second section switching B+ on/off to the mixer stage.

I would seriously de-consider replacing the switch as that could turn into a real can of worms.

[vortalexfan]

Originally Posted by old_coot88

Turns out there's an obscure little subnote to the main schematic, showing the radio/phono switching diagram. It's difficult to decipher, but shows the switch as DPDT (double pole/double throw), with the second section switching B+ on/off to the mixer stage.

I would seriously de-consider replacing the switch as that could turn into a real can of worms.

Well I really wanted to use the record player on this thing, as it has a nice modern VM 1200 series record changer installed in it.