RCA Victor portable TV from the 1950s

[vortalexfan]

Originally Posted by jr_tech

I suspect that you may find problems in the vertical section as well.

jr

I completely recapped the vertical section already and was still having issues which was what lead me to the conclusion of the failed dag coating was what was causing my problems.

[vortalexfan]

Originally Posted by old_coot88

Yes indeed. It can cause symptoms out the wazoo mimicking sync, AGC and tuner erraticies galore.

Ok, that answers my question. Hopefully repainting the dag coating on the picture tube will repair my remaining issues.

[vortalexfan]

Originally Posted by JohnCT

You can also use duct tape or painter's tape to remove any flaking dag. Anything that survives a tape pull is fine to paint over.

John

Ok, I might give that a try.

[Eric H]

Doubtful the Dag is causing the picture issues, did you replace any of the electrolytic capacitors? There's usually one on the Cathode of the output tube that will cause the picture to shrink if it's bad

[old_coot88]

Originally Posted by vortalexfan

Ok, that answers my question. Hopefully repainting the dag coating on the picture tube will repair my remaining issues.

Only if the dag is arcing due to bad ground, isolated 'islands' etc. will it cause the problems described earlier. The arcing generates crazy amounts of hash that gets into the signal chain.

[vortalexfan]

Originally Posted by Eric H

Doubtful the Dag is causing the picture issues, did you replace any of the electrolytic capacitors? There's usually one on the Cathode of the output tube that will cause the picture to shrink if it's bad

There's nothing wrong with the vertical size/height anymore, I replaced all of the non-mylar capacitors (paper caps) in the vertical circuit, and the TV went back to being full screen again, now what I'm having issues with are screen flickering and bouncing issues.

[vortalexfan]

Originally Posted by old_coot88

Only if the dag is arcing due to bad ground, isolated 'islands' etc. will it cause the problems described earlier. The arcing generates crazy amounts of hash that gets into the signal chain.

Which I think is what this tv is doing.

[old_coot88]

If the dag is arcing, you should be able to see it in a darkened room.

[vortalexfan]

Originally Posted by old_coot88

If the dag is arcing, you should be able to see it in a darkened room.

I think I was seeing it arcing, if you take a look at the video I uploaded onto YouTube showing what the TV was doing when it was operating, you can see a lot of flickering in the screen which is I think the dag arcing.

[JohnCT]

Originally Posted by vortalexfan

I think I was seeing it arcing, if you take a look at the video I uploaded onto YouTube showing what the TV was doing when it was operating, you can see a lot of flickering in the screen which is I think the dag arcing.

It certainly will do no harm to renew the dag, so have at it. At least if the symptoms don't improve, you'll know what it wasn't.

John

[vortalexfan]

Originally Posted by JohnCT

It certainly will do no harm to renew the dag, so have at it. At least if the symptoms don't improve, you'll know what it wasn't.

John

Exactly. But since the TV has mostly Mylar caps in it except for the 8 paper caps that were in the vertical section and that were coupling/decoupling the H-output tube the TV shouldn't be having too many problems since I had replaced those aforementioned paper caps and the electrolytic can caps are still functioning as they should.