Capehart 661-P

[Phil Nelson]

Thanks. Maybe I should go back and re-post those schematic bits in PDF rather than JPG format.

The schematic is arranged differently than most, which makes the sweep sections harder for me to follow. Anyhow, the horizontal/AFC subchassis communicates through its adapter plug. That subchassis labels its tubes as follows:

6SN7GT: Sync Amp
6K6GT: Sync Osc
6AL5: Sync Disc
6AC7: Control

I have replaced all resistors around the vertical tubes except for numbers 53 and 15. Until I did that, the vertical had major foldover on the bottom (Ingrid Bergman image) and it was impossible to get correct linearity through the entire height.

For the last photo (Scarlett O'Hara), I was trying to set the image size to fit the TV's little mask. The height is about right, but I can't bring in the width any narrower, suggesting (along with other symptoms) that the HV is insufficient. The designers may have planned for some horizontal overscan, but this amount would cut off way too much behind the mask.

The vertical controls have lots of range and they are very interactive. I can make the picture much taller, which looks better on the round screen, but that wouldn't work when I put it back in the cabinet.

I'm a little surprised that the TV looks this good. I initially turned up my nose when I saw that it lacks an HV cage and has minimal shielding on the tuner, but it can make a razor-sharp image with good contrast. The DC restoration is not the greatest, but I haven't looked at that part yet.

Phil Nelson