The PHILCO Phorum

Good morning

I have a Crosley 10-136  http://www.nostalgiaair.org/Resources/172/M0003172.htm

I have recapped it and it plays but there is a problem with the Vol so I thought I need to check it out especially since it looks as though it has been replaced. The Pot Resistance show 500k the Print shows it should be 3 meg and a tap at 300k ( parts list). I googled 3meg pot and the highest I see is 1meg and see no tap. Any suggestions on what to do? I have a couple of sites to try yet but I'm not hopeful. Thanks

Eric

Hey Eric,
Not quite sure why they spec such a high value control. The one thing that comes to mind is the it does act as a bit of a load for the phono. The higher the input load the better the frequency response with a crystal cartridge. The tap is for audio frequency compensation (tone) at low volume levels.
Given the type of set and size of the speaker I would think that if you did change out the control the difference would be negligible.

 Terry

Terry,
I sent an email to Mark Oppat to see what he has and I was poking around Play Things of the Past and did find some tapped 3 meg pots he doesn't say if they have switches but will wait till I hear from Mark before contacting him.

What got me looking was the low volume even when turned up all the way and figured it was the 500k pot.

Eric

For grins you could turn the volume full up and disconnect the ground (B-) side of the volume control. This will give you flat out all she'll do volume wise.

Terry

For a test, I have tack soldered together a series of 3 or 4 fixed resistors totaling the value of a POT and connected the center tap to a clip lead, moved to different points between resistors to check. It'll give you an idea of where things stand with parts you may have on hand.

Ok I got the correct pot but which is the 300k tap? The lead going to the .002 cap and on to the 12AV6? Or the 680K/47K lead I suspect the later but I want to be sure as the quality of the print is not that good.

Eric