my roundie zenith

[newhallone]

I have been getting my bench set up a little bit for winter for some projects one of which is my Zenith roundie which I posted about earlier. I will be ordering caps soon. Todays question is I noticed a vertical line on the left hand of the screen and faint retrace lines. Also a brightness at the bottom of the screen. Any thoughts on these symptoms? The retrace lines are not visible in my pic.

[reeferman]

it's been a long time..as far as the line..I would check the draw on the HO tube and circuit, and check the damper and surrounding areas. How is the high voltage and is the regulator working? I may be totally off, but I would start there. Keep us posted and good luck

[fsjonsey]

Could the vertical line be barkhausen interference?

[newhallone]

Thanks good things to look for! I was a little suspect on the Ho. Can't wait to tear into it.

[bgadow]

If you have a spare HO tube I would swap it; with the prices of some of them, I don't know if I would run out and buy one just for that. The line sure looks like barkhausen. You could try moving a magnet around near the tube and see if that changes anything.

[newhallone]

I think it's running around 13 bucks or so. But I will try a magnet this weekend. It has some faint retrace line too. Hopefully the crt is not on it's way out.

[reeferman]

Are you referring to the lines at the bottom of the screen as retrace? If so, I've never seen 'em like that. (I had a nickname of retrace for a while because I could make them appear out of nowhere, especially on -15s and -16s). I don't think it is Barkhausen.

[newhallone]

Nope. It has retrace lines. They just don't show up on my crappy cell phone pics. I am going to try and get my old camera to work and try to get some better pics on something besides a blue screen.

[3Guncolor]

You need to get good video on that set before you worry about retrace lines.

[Phil Nelson]

I would recap the set and then see what you've got. It's futile to try to do detailed troubleshooting on a TV when you already know it has dozens of bad capacitors.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[newhallone]

I absolutely agree.

[drh4683]

Ive seen this before. If you adjust the horizontal hold control, you can move that bar off the screen, and it might shadow over to the otherside. Its horizontal blanking problem. I had this same problem on a 20Y1C48 and was caused by a leaky horizontal phase detector diode. In these sets, the phase detector diode is two individual glass germaniums. Try subbing the 6U10 first. There are probably only 3 black BB caps in that chassis. I restored a 25LC20Q a few months back and only had 3 under there. I suggest not recapping the entire set. The only time I recap a set is if it has BB's or paper/wax caps. That chassis has many mylar caps, and those are very quality good caps. Same with the electrolytics. I check ESR on the originals and if its good, the cap stays. 95% of the time, they check good on the 60's TV sets. Ive been using alot of my old sets for YEARS on the original lytics with no problems. There was a considerable quality/reliability improvement in components by the early to mid 60's compared to the 50's. TV's.
Im big on keeping a TV all original if at all possible.

[newhallone]

I tried the the horizontal hold and that is whats going on. Thanks for the tips. I have an order in for caps and some tubes. I'll see if they can add the 6u10 to the order. Do you remember what the sub is for the diodes? Just in case. Again thanks to all!

[newhallone]

I haven't been working on this lately. Other irons in the fire. But I do have caps for it. Do I have to worry about cataracts with this set? There is no trace of them yet. If so is the correct procedure to silicone around it to make sure the air don't start the process?

[bgadow]

Which picture tube is it? I get them mixed up, but from what I've seen, the ones that do not have the "etched" (anti-glare) safety glass were not bonded. The glass is just held on with a gasket. That type can't get cataracts, though at some point you may need to disassemble it as the gasket can leave an oily residue. I may be wrong, but I think if they are going to get cataracts they are going to be there already.