1947 Crosley 307TA (630 clone) issues

[earlyfilm]

Originally Posted by Kamakiri

We're thinking possibly the contrast control at this point, not sure. It was VERY touchy before this, and now I'm wondering if it's the culprit.

The factory manual was listed in my early post.

As you said, the control is RCA part number 73157 with no cross reference.

Picture half is 10K Ohms tapped.

Volumne half is 1 Meg Ohms tapped and with AC switch and dual shaft length to fit early RCA. (The same control is found in some clones, including Teletone look-alikes that were not clones.)

Correction (07/27/2013):

Sorry folks, I kinda put my foot in my mouth on this one.

I looked about for another same combination control with switch and could not find one.

I suspect the only commonly available replacement control would be from an RCA 8TS30. Before I'd go looking for a parts set, I'd first confirm that the control is at fault and, if so, open it and see if it can be repaired, possibly by robbing a 10K element from another control.

While some of the other early sets used similar circuits, but after this one, I don't think anyone ever put the volume and a gain-type of picture control on the same shaft.

It seems too many people accidentally bumped the picture control while adjusting the sound and could not understand what they had done to mess the set up.

Jas.

[bigaudioal]

Thanks Jas. Wondering if the KCS-47 has same control?

[bandersen]

The KCS-47 has a 1.5M with two taps for volume and a 2.5M tone control along with the AC switch.

[bigaudioal]

Jas, thanks for the clarification to your earlier post. I am going to try and test my pot this week sometime. So, the values you list above for it are correct, you just think it is not a control that was common to other sets now?

I have a spare set coming, so if it is a bad pot and cannot be repaired I will have a back up.

THANKS!

[Kamakiri]

It appears that the contrast control is okay.

Is there a way to inject a channelized signal into the set at some test point, bypassing the tuner?

[Geist]

Hi All;
Sure, If you have a B&K 1077 or something similiar..
THANK YOU Marty