I have a model TV-37 I'm working on. This is my second one. My first one didn't have this same issue with what appears to be AC ripple disrupting the Horizontal and slowly makes the image do the "snake" The symptom is a Hula dancing effect with the Horiz. The pulling only occurs when a video signal is present. When there's only raster, like just at start up, the image is stable.
https://youtu.be/EPdc9n_1bpI
I have found a bit of AC current leaving the 35W4, which is the B- rectifier.
On this set the B- feeds the Sync, Horiz Osc and cathodes of vert and horiz outputs.
I have found approx 2.3VAC on the plate of the 35W4 and the following AC values found on the
cathodes of the following tubes.
35W4: 2.2 VAC
Hor Osc: .2V
Hor Out: .2V
Sync: .2V
HV Osc: 1.5V
Vert Osc: .28V
Vert Out: 1.3V
AC is not found on measured cathodes fed from the B+, which is the 25Z6 dual rect, even though I measured 9vAC on the cathode of that tube!
This set adheres more to the Rider version of the schematic than the Sams. Here is a link to the PDF, from Phil's site:
https://www.antiqueradio.org/art/Pil...7RidersTV2.pdf
Work I have done up to this point:
All original filter caps have been replaced with tested new caps twice, just in case there was an undetected defect that my capacitance and ESR tester didn't catch. Added an extra third 120uF parallel to the B- filter caps which lessened the pulling. Adding an extra parallel to the B+ does nothing.
All non polarized caps replaced, including all small value ceramics and coupling types.
All deflection caps replaced with WIMA HV film caps, except for the cap in the HV cage which was replaced with a 10KV ceramic. Note: this problem existed before and after the in-cage cap replacement.
All tubes have been swapped out with tested ones and this doesn't improve the symptom.
I know this is a lot of info, but I've kind of hit a wall here and am looking for ideas if anyone can enlighten me.
