[Dubis7]

Hi all,

I'm looking for some guidance on a 1960s RCA Sweet 16 sportabout I'm in the process of restoring. It was working fine until just a few months ago, when it developed some disturbances, almost like an AC buzz but visual, in the picture. It would react to tapping on the cabinet, sometimes getting better or worse. Then, I noticed that adjusting the Horizontal Hold pot actually caused the picture to disappear entirely, but it would always come back when I moved it back.

So, with my AC theory in mind, I went ahead and replaced the electrolytic can and the glorified paper safety cap across the AC line. Those replacements appear to be fine, no obvious trouble. It's turning on faster than before, and I'm getting perfect sound.

However, my picture is gone.

I noticed that the HV rectifier tube in the cage was still cold after running it, and there was no high voltage whine, so I replaced that tube. Now, the whine is back, it gets louder when I adjust the horizontal hold, but the picture is still absent. Placing a screwdriver against the HV rectifier cap in operation is giving me a healthy blue spark, so I know my flyback is fine, and I've also verified that the resistor across the HV rectifier tube socket is up to speck, and that the lead to the picture tube appears to be fine, though my continuity there did seem to cut in and out at times, so perhaps that warrants another look. The tube is definitely still under vacuum.

I'm thinking my issue either has something to do with the Horizontal Hold pot, the picture tube HV lead, or how I'm installing that cable. The amount of clip that actually goes inside the tube is much smaller than I expected, but I also can't see any way for it to go further. Regardless, it's not falling out or sparking. Considering where I started, does anyone have any suggestions for where I should look next? I don't have a HV test probe, though I'm willing to get one if it's necessary.