Philco Issue

[VA561]

I have a philco tv model 50T-1404. I play the set for two hours at the most at some point during each weekend. The set plays great but has developed a peculiar issue when I first turn the set on. When first powered up (cold) the horizontal is out of adjustment. Regardless of which way I turn the adjustment knob I cannot get a picture. However, without fail, if I pull the plug and wait a few seconds and plug it back in, presto, I have a picture and everything is fine from then on. The horizontal width and linearity adjustments on the back of the set do not seem to have any effect when I turn them. Your expertise would be appreciated.

[John Folsom]

Which model/chassis number is your Philco? If it has a horizontal oscillator coil or transformer, you need to adjust it. Consult the service data for your set for the horizontal adjustment procedure.

[Eric H]

As John said, there is a coil somewhere on the chassis for the fine adjustment of the horizontal oscillator, it needs to be tweaked to get the front coarse control back in the center of it's range.

I can't remember right off where the coil is on that chassis, I think it might be on top of the chassis near the Flyback cage but I'm not sure, I can find out tonight.

[Eric H]

Just checked the schematic at the ETF and it looks like it's coil B4, it's mounted in a can on the top front of the chassis next to the Horiz Osc tube, a minor adjustment of that coil should bring it back to center.

There's also the possibility that the Osc tube is a bit weak and doesn't run well when it's cold but often you will have to readjust this coil when the tube is replaced anyhow.

Schematic is here: http://www.earlytelevision.org/pdf/P...Sams-115-8.pdf

[DavGoodlin]

On page 18 of the sams, there is a great procedure for the horizontal range.

[VA561]

My chassis label is reading code 121. The sams is showing codes 123, 124, and 125. B3 and B1 are there but I don't see B2 and B4. Something must have changed with that code.

[VA561]

I want to thank everyone who has been helping me to solve this problem. All posts are greatly appreciated.

[John Folsom]

I believe the schematic for your chassis (code 121) is here:
http://www.earlytelevision.org/pdf/P...Sams-114-9.pdf

This version uses a slightly different configuration for the horizontal blocking oscillator transformer; it does not have the extra ringing coil winding on the transformer.

[VA561]

Thanks John. That is what I was looking for. Thanks again for everyone's input.