1958 RCA 14" Deluxe 14-PD-8057D

[ZackN920]

Hey y'all. I don't know if any of the VK'ers visit ARF but I need some help with this thing and the TV section there seems to be sparse. I don't like the idea of sending y'all to another site but here's the link to my thread: http://www.antiqueradios.com/forums/...p?f=3&t=231875

General gist of it,
This is the first TV I baught, rouphly when I was 15 ('07-'08). I fiddled with it some and got it to show a good picture for about 5-6minutes. Then it would lose Horizontal hold and would be unable to get it back because of being very finicky. I knew nothing of recapping old radio's and TV's at the time and wouldn't have anyway's if I did know of it.

Fast forward to this year and I want to see this basterd that's been sitting on my dresser working, and I want it to be stable for much more than 6min's.

I finally recapped it this last week, and it was a bitch. It's got a metal plate that block's the back side of the pcb and it is soldered in several spots. I couldn't get it apart so I had to unsolder some wires and junk to get the board to pivot enouph to get it all apart and start work. Anyway's I replaced all paper caps and lytic's and got the chassis all back together along with the CRT back in place. I did not replace the selenuim rectifier's. I have 1N4007 diodes but I know nothing of figuring out the correct resistor values to use with the diode's.

Here's the results:
It has a pretty good pic... but it now has screen interfearance, Looks like snow. You can see the full image, but the screen has dots all over it, that mimics snow but when switched to a channel that has nothing, you can see the regular snowy pic with this same issue overlay'd on top of it.

I also noticed that a bar will go up the screen then re appear at the bottom and repeat. It's slightly lighter than the image and it doesn't disturb the image. Mabey something off sync? It never had it before.

Also noticed that verticle hold isn't as good as it used to be. As it's warming up the picture will either roll up or down. I don't know if it was set up to operate better on some of them out of spec caps or if a tube is giving up. Once it's warmer it got more stable but if ya made any adjustment the picture would roll.
Would that little springy peice of metal above the CRT have anything to do with these issues? It's not touching the CRT and i've seen other sets that have something like that on them that are touching their crt. Ive also read somewhere (if im thinking correctly) that some televisions don't operate properly outside of their cases. Would that have anything to do with this?

Today, I also noticed that it's arcing? at the anode on the CRT. Solid purple glow and hiss. I'm not that surprised though, since the set has no HV cup that cover's it. Just the end of that spring like conducter and a piece of (electrical tape looking) thing wrapped around it. It was also real hot (95ish) and humid today and there is no temp control in the building that my workbench is in.

Anyway's here's a video I took today. In the vid I mess with the contrast, fine tuning and the vert. hold a little bit.

http://s467.photobucket.com/user/ZN0...e78da.mp4.html
Hopefully the vid works for you all. Any help and advise greatly appreciated!


Sorry for the long post, especially if it sent ya to some zzz's

[rca2000]

That video noise is probably arcing. Arcing WILL cause noise in the raster so If you see arcing or corona, you need ot get RID of it, and that noise likely will go away with it.

[Tubejunke]

That video is scarier than a first day in grammar school!

[DavGoodlin]

The arcing might be due to the picture tube's external ground coating (aquadag) is not making good contact with the grounding spring, which sticks out from the chassis.

Otherwise it looks pretty good.

[ZackN920]

Corona!(couldn't remember what the word was earlier) That's what its called that it's doing, right at the CRT anode. Hissing and arcing sounds along with it!

Originally Posted by DavGoodlin

The arcing might be due to the picture tube's external ground coating (aquadag) is not making good contact with the grounding spring, which sticks out from the chassis.

Otherwise it looks pretty good.

Really?, I didn't know ya had to have it grounded. Yea, the spring like thing that would be on the CRT is floating above it about 1/4". Coulda sworn I seen it arc there earlier today when I was messing with the set.

Hey Electronic M, I was cleaning around it this afternoon. Didn't have glass cleaner though so I only cleaned the anode and the spring connector. That crappy looking thing around the connector that looks like electrical tape itself, looks dirty inside and slightly sticky, so I don't know how much cleaning it will help. I wonder why some sets never got HV suction cup's like this one. Then you'd rarely have to worry about shit like this.
I know that the set wouldn't have been designed around failing caps, but I didn't know if some crafty repairman could've modified it. Anyways I think I'll check into more after I get the arcing/corona/video disturbance fixed first.

Hey JR, yup, I replaced the filter caps. Some arn't the exact value as before, but I made sure to get as close as possible. I even combined a few to get close the exact specs.

Hey Eric, I cleaned it (other than the glass) and powered it up and the damn thing threw a spark out the back at a capacitor lead. I can't really move the tube out any farther. I must have had the wrap (cover) pushed to close to the anode connector.

Later today I may go back out there. Clean some more on the glass around the anode, and bend that spring piece of metal to sit on the crt. Then try it out again. Thank's guys for the help and advise so far!

[Electronic M]

Dave makes a good point. Definitely make sure the aquadag is properly grounded to the chassis. Have you cleaned the area around and including the HV connector on the CRT? And if not are you familiar with the proper procedure to discharge the HV? If the answer to the first is no then discharge the HV and use windex and or rubbing alcohol to clean the bare glass between the edge of the aquadag and HV connector...Also disconnect the HV lead and clean the CRT HV connector, HV connector on the lead and a few inches of the lead it's self. That and grounding the dag should kill the arcing and reduce interference. If the HV connector has developed sharp edges that promote arcing/corona no matter how clean you make it then one option is to find a junk ~90's era CRT set and pirate the HV lead and suction cup HV connector out of it to use as a replacement for the HV lead and connector in your set.

If your set has AGC then you may want to adjust it for best synch stability. Your set was not designed to work better with bad caps, but if resistors drifted outside of rated tolerance (ie. went bad) in a way that compensated for the bad caps then installing good caps could throw that balance off...The solution is to look for out of tolerance resistors and replace them to restore vertical synch stability.

[jr_tech]

I would not be surprised if the vertical stability improves once the arcing is stopped. Did you replace the filter caps? The slowly rolling disturbance observed could be 60 Hz hum.

jr

[Eric H]

The 2nd anode can arc to the chassis or component if the CRT is too far back, if it's arcing to the tube itself then it must be dirty around the anode connector.

Cleaning it with a little alcohol should fix that (make sure it's discharged first of course).

[Electronic M]

In case you are curious the reason the outer dag coating needs to be grounded is to filter the HV...You see the inner conductive dag connected to the HV separated by the glass dielectric from the outer grounded dag forms a capacitor that filters the HV. The outer dag can float up to HV potentials when not grounded.

[Jeffhs]

I can't see the video of the 1958 RCA TV. Looked on the Photobucket page; couldn't find it there. Has the video been deleted, is the link broken or obsolete, or...?

[ZackN920]

Originally Posted by Electronic M

In case you are curious the reason the outer dag coating needs to be grounded is to filter the HV...You see the inner conductive dag connected to the HV separated by the glass dielectric from the outer grounded dag forms a capacitor that filters the HV. The outer dag can float up to HV potentials when not grounded.

Huh, I didn't know or even figure of it. Learned something new about these! I didn't know that HV filters threw the glass and to that surface, but it makes scence. If it helps the HV to pull threw that anode.

Hey Jeff, the video is there last time I noticed but photobucket keeps getting worse and worse and I can't even view it on the PC that I used to put the video on with. Works on this iPod though. I don't know what to say.

Well I got a new video of it. That spring being on theaquadag did really help with the sizzling and what not, but I still have those dots on the screen.
http://s467.photobucket.com/user/ZN0...2b85b.mp4.html
Hey username1, I'll get back to ya on the status of my tuck project later, I gotta go to work!!

[Username1]

Hey Zack; I like yer Dakota, I got an '88 V6 HD 2WD. Did you fit that 318 in there....?

I know the V6 was 80% 318, but I don't remember if that style actually had an
original design 318 in it as an option.....

.

[ZackN920]

Well, I changed out my little cable to 2 wire transformer(can't remember actual name) and found operation did not change and that the one I was using was fine. I did notice that when no signal is applied to the set, channels 2-7 had some odd lines and stuff on the screen while 8+ had regular snow on the picture. I'm thinking some of this could be tuner issues. I don't know how they have developed since I haven't touched it durring recap but something's f'd up. Suggestions welcomed and appreciated....

[ZackN920]

Any Idea's/help?!

Anyway's for now, since I needed to get a radio on the bench, I put the TV back in it's case. Some of its issues in the mean time cleaned up a little bit. Still has a snowy pic, but not as bad. Fine tuning has to be advanced all the way or it will have nothing but shush for sound. For some reason the screen now will go dark soon after shut down. Now I don't have to worry about the CRT getting an ion burn...
I have found, that the set is stable. I ran it for an hour and a half yesterday, when I was working out. Only things I noticed was that the image moved slightly to the right (which is corrected with horz. hold) and a verticle snow bar appeared on the left side of the screen, which wouldn't move. Not very wide, probably about 1/2" wide. It does run pretty hot, but it wasn't too bad for the leangth of time.
I'm still not done yet. It still has snow/interference. It didn't have it before the recap. I'm unsure as to where to go from here. Mabey test the tubes on that tuner??? IDK...

[Electronic M]

If you have yet to do so clean the tuner contacts. If your set has AGC adjusting it can help. Given the fine tuning issue your set may be out of proper alignment.