Philco 50-T702 7 Inch TV

[reichsrundfu]

Well guys I think I'm there. I found that the root of the vertical linearity issue was a mic capacitor (C73) which couple the first and second sections of the 7F7 vertical amplifier. After the set would warm up, and even with the new resistors there was still some flattening at the top, so when i freeze sprayed that cap the picture came right back up. This is a 100pF capacitor. Soldering in a replacement did the trick. All and all, Im really pleased with the linearity. After getting the chassis back into the cabinet I'll make final adjustments of the height and width, i typically set it 10% oversweep to compensate for voltage variations.

The image is actually a lot sharper than you see in my picture, but I had to set the picture like this to get a good shot of the test pattern. Its quite nice to watch, actually...... After around an hour I do notice the picture gets a bit darker which is typical of this set, but I have plenty of adjustment room on the brightness so i can just tweak it up a bit and I'm fine.

-George-

[reichsrundfu]

Update for your guys: all done and all buttoned up. I encountered a slightly "rare" issue with the vertical sweep which delayed finishing this. The brand new 100pF capacitor I installed which corrected the linearity problem suddenly began to fail! After about 10 minutes the vertical height would begin jiggling erratically downward off and on. Replacing it with another new capacitor corrected the issue and after a good 8 hours of play time I think she's reliable and ready to close up. Here is what it looks like now!

-George-