I've recapped the G.E. 862, tweaked the variable caps and now it sounds good and has impressive sensitivity/selectivity. The problem is with the volume-on/off switch. It's the type that you pull to power on the radio.

When the switch is turned all the way down, there is hum with some audio. As the volume is turned up about a eight of a turn, the hum is gone and the volume is almost nonexistant. As the volume is increased, the audio is fine, no hum. I'll mention that the radio also has a phono input, but this may not make any difference.

I'm not sure what to look at next. Thanks in advance for any suggestions.

Gary

I'd first check the condition of that resistor/pot.
Disconnect the wire from the volume control wiper and one end. Then measure the resistance while you reach that low end to see if it exhibits screwy readings at the bottom end. If it does you may be able to clean it with contact cleaner spray or else open it and clean it.
...or as another quickie test...You can temporarily substitute another new or good pot with jumper leads to see if the problem goes away. If so you can clean the old one or replace it.

Hi Peter. I owe you an email or a phone call to let you know what I've been up to. This restoration went easier than the first. I'm able to do more since I came to visit a few weeks ago.

I sprayed the switch and it really didn't help. When I get home I'll try the measurements. It's almost like the pot is working in reverse, but nothing that bad. I'm not sure where to get a replacement. Radiodaze didn't look like they have this part. The set is not particulary valuable, so I don't want to invest too much into it.

:I'd first check the condition of that resistor/pot.
:Disconnect the wire from the volume control wiper and one end. Then measure the resistance while you reach that low end to see if it exhibits screwy readings at the bottom end. If it does you may be able to clean it with contact cleaner spray or else open it and clean it.
:...or as another quickie test...You can temporarily substitute another new or good pot with jumper leads to see if the problem goes away. If so you can clean the old one or replace it.

Glad to hear your progress Gary.
Yes after each visit you will progress even more rapidly... you won't believe how fast you grow.
I see it in myself.
I do projects much better now and even do somethings now that I wouldn't think I'd do a few months ago.

Pot:
If this ia a 500k ohm pot (audio-taper remember ...not linear) and if it needs to be replaced and it has a switch on it...
Go to:
www.Tubesandmore.com

R-VS-500KA
2006 Catalog
page 44
POT - SPST SWITCH, 1/4" x 1 3/8" SHAFT, 500K AUDIO
$2.95

Peter, where possible, I'd like to come by again and watch you work and/or help and maybe diagnose another one or my problem radios. Thanks for the tip on finding a replacement part. The faulty pot is perhaps the least of my problems at the moment with this radio.

The radio is now exhibiting nasty intermittant static crashes, and this wipes out the entire audio just like your current project. The radio is from 1957 give or take a year. Were there silver micas in the IF cans during this period for GE radios? Thanks.

Gary

:Glad to hear your progress Gary.
:Yes after each visit you will progress even more rapidly... you won't believe how fast you grow.
:I see it in myself.
:I do projects much better now and even do somethings now that I wouldn't think I'd do a few months ago.
:
:Pot:
:If this ia a 500k ohm pot (audio-taper remember ...not linear) and if it needs to be replaced and it has a switch on it...
: Go to:
:www.Tubesandmore.com
:
:R-VS-500KA
:2006 Catalog
:page 44
:POT - SPST SWITCH, 1/4" x 1 3/8" SHAFT, 500K AUDIO
:$2.95

Gary, I suspect that your probem, unlike Peter's, is the "dreaded" silver-mica disease. Are your IF xfmrs 3/4-1" square? Those are most often the ones.

There are solutions to this problem, if I'm right about your situation. Do some googling. Basically, you need to cut the silver-mica sheets out of the ckt, and replace with 100-pF or so silver-mica caps, which can be hung below the chassis.

:Peter, where possible, I'd like to come by again and watch you work and/or help and maybe diagnose another one or my problem radios. Thanks for the tip on finding a replacement part. The faulty pot is perhaps the least of my problems at the moment with this radio.
:
:The radio is now exhibiting nasty intermittant static crashes, and this wipes out the entire audio just like your current project. The radio is from 1957 give or take a year. Were there silver micas in the IF cans during this period for GE radios? Thanks.
:
:Gary
:
::Glad to hear your progress Gary.
::Yes after each visit you will progress even more rapidly... you won't believe how fast you grow.
::I see it in myself.
::I do projects much better now and even do somethings now that I wouldn't think I'd do a few months ago.
::
::Pot:
::If this ia a 500k ohm pot (audio-taper remember ...not linear) and if it needs to be replaced and it has a switch on it...
:: Go to:
::www.Tubesandmore.com
::
::R-VS-500KA
::2006 Catalog
::page 44
::POT - SPST SWITCH, 1/4" x 1 3/8" SHAFT, 500K AUDIO
::$2.95

Sure Gary... anytime

Another thing you can try to do is connect the volume control low side to the cathode of the output tube (when a cathode bias resistor is used, and the volume control is normally on the negative side of this resistor). Connect a 30 MFD condenser across the resistor.

Thomas

Thomas:
How will that fix a bad pot?

It can sometimes fix the hum.

Thomas