Thread: 1963 Philco
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Old 05-02-2007, 09:06 PM
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Adam Adam is offline
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Join Date: Oct 2005
Location: Phoenix, AZ
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Working again.

The plate voltage at the 6EW6 is supposed to be 400v, and not 50, I checked it against another schematic and then I checked it again after the set was working (the 50v must be a misprint). The screen voltages and grid voltages were a bit low, but not by much.

The color intensity control would cause it to go from a b/w picture to a b/w and green picture.

The voltages at the 6JU8 phase detector would vary from 20 to 40. When I checked it the set would loose color sync all together and have the horiz color lines, but when I removed the meter it would go back to white and green.

Anything hooked to the 265v source tested about 30v low.

I replaced several resistors that were 10-20% off, but it made no difference.

Finally, not being able to find the source of my troubles, but pretty sure it did have to do with the color sync circuits, I hauled the scope behind the set and tested the 3.58mhz oscillator. I was getting a signal, I was trying to figure out if the frequency was right or not, then I just decided to try to hook the probe to one of the leads going to the crystal, and see what I got, then when I looked at the picture on the screen (the set not the scope) the color was back. I removed the scope probe, not working again. I tried just clipping a wire where I had the probe, and it still worked. I resoldered the crystal to the board, and that was all it needed.

A different Bewitched Zenith...

Last edited by Adam; 09-13-2009 at 10:37 AM.
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