Latest Score From 64 - Page 3 - Videokarma.org TV - Video

damen · #31 03-20-2010, 10:21 AM

Quote:

Originally Posted by zenithfan1

Check the Horizontal circuit really well, it looks like that is the problem. It can also be the reason the color won't lock.

I will do that and thanks for the tip.

Jeffhs · #32 03-20-2010, 10:44 AM

Quote:

Originally Posted by zenithfan1

Check the Horizontal circuit really well, it looks like that is the problem. It can also be the reason the color won't lock.

That is 100 percent correct. A color TV picture must be firmly locked in sync for the color to be stable. Poor horizontal sync, in particular, will cause color sync problems as well. I had a roundie color set years ago with very poor color sync, but I didn't know at the time (early 1970s) that the horizontal was tied in with the color. Had I known then what I know now about the link between solid horizontal sync and color sync, I could have enjoyed that set a little longer with a good picture. As it was, every time the color would go out of sync, I had to turn the tint control from one extreme to the other several times to get it to lock. That symptom alone should have told me right there something wasn't right with the horizontal, but I was a 17-year-old kid at the time puttering with the set at random and didn't know any better. Finally had to get rid of the set a year or so later, when the video output circuit board cracked while trying to replace the tube.

*zenithfan1* · #33 03-20-2010, 10:10 PM

Quote:

Originally Posted by damen

I will do that and thanks for the tip.

You're welcome, I hope you get this beauty runnin' soon

damen · #34 03-26-2010, 11:32 PM

Well I found that the horz det. Diode pack had one side open bought a new one and wow it works but it does still need more work it still goes out of synk sometimes when you change channels or adjust the horz hold and I see retrace lins when the screen goes blank like in between a show and a camershal. I will have to do some more serching for the problem. I also did find the date under the chassie and it is April 15 1963 The picture of it working is on the originanal post with the other pics.

Kalamazoo-DJ · #35 03-27-2010, 09:24 AM

That is a very nice looking set I have always liked the RCA roundie as a favorite.

marty59 · #36 03-27-2010, 11:39 AM

Sounds like some minor issues but you're about there!
As for the retrace lines, common with RCA's..Check resistor values around the pix tube bias switch, normal service switch and out towards the drive and screen controls as well as B+ and B+ boost. Those slide switches aren't the best, either. I'll bet there's some drifted resistors!!

And when you say the color is not locking in you're seeing "color bars"..My CTC-16 has that issue but if I move the fine tuning back and forth just once it locks so I've been kinda putting up with it. I've had this set since '76 and it's always been like that..doesn't make it right though and I would like to correct it...when I can get back to it!!

I know this problem has been discussed here by others, and I need to be reminded of the solutions too. Not uncommon...

marty59 · #37 03-28-2010, 02:25 AM

Ok, thought about your color sync issue. Horizontal is good and stable now? Even if it's drifting a little, color will go out. Make sure your horizontal hold control is set so you move it in either direction an equal amount to determine it's most stable point. (as a side note, is the pot somewhat centered in it's range?). All good here then there's some things to check on the chroma board.

For starters, make sure the 6GH8 for the 3.58 Mhz is ok, as mentioned elsewhere and I agree 6GH8's can test good but still not work too well in the circuit...try a couple and observe your results.

Is yout tint control centered or close to center? (easy fix).

Check the 6EW6 and the 6JU8 tubes too. Grounds and wire leads ok? RCA Chroma Boards have wires running on the component side that will get corroded where they run into the feedthroughs and possibly become poor connections. Solid grounds verify too.

After all this, check voltages on the 6EW6 and 6JU8..ok?

damen · #38 03-28-2010, 11:03 AM

Quote:

Originally Posted by marty59

Ok, thought about your color sync issue. Horizontal is good and stable now? Even if it's drifting a little, color will go out. Make sure your horizontal hold control is set so you move it in either direction an equal amount to determine it's most stable point. (as a side note, is the pot somewhat centered in it's range?). All good here then there's some things to check on the chroma board.

For starters, make sure the 6GH8 for the 3.58 Mhz is ok, as mentioned elsewhere and I agree 6GH8's can test good but still not work too well in the circuit...try a couple and observe your results.

Is yout tint control centered or close to center? (easy fix).

Check the 6EW6 and the 6JU8 tubes too. Grounds and wire leads ok? RCA Chroma Boards have wires running on the component side that will get corroded where they run into the feedthroughs and possibly become poor connections. Solid grounds verify too.

After all this, check voltages on the 6EW6 and 6JU8..ok?

Thanks for the the help on this but it is the horz. sync that still goes when when you change chanels on it and the the horz hold has to be reset I am sure its not a tube the horz output and sync tube is new and all the tubes
check very good I have checked all the resistors on the horz \ vertical board. I am going to do that on the crohma board and double check all the grounds.

marty59 · #39 03-28-2010, 01:13 PM

This may be a silly question, do you have a scope? You should be able to pin down where the horiz is losing itself. I'd make sure the takeoff point at the sync seperator is good/stable first as a point of reference.
Are you able to work with the chassis out of the set, attached? I've done this before with my '16, had to prop it up from the floor vertically and I made an extension lead for the HV. The tuner bracket assembly will mount by the A/C plug, fastened by two 1/4" hex screws.

damen · #40 03-28-2010, 02:07 PM

Quote:

Originally Posted by marty59

This may be a silly question, do you have a scope? You should be able to pin down where the horiz is losing itself. I'd make sure the takeoff point at the sync seperator is good/stable first as a point of reference.
Are you able to work with the chassis out of the set, attached? I've done this before with my '16, had to prop it up from the floor vertically and I made an extension lead for the HV. The tuner bracket assembly will mount by the A/C plug, fastened by two 1/4" hex screws.

I do have an old tube type scope a friend gave me but I have no cables for it and I have never used a scope before but I want to learn how. I think it would help make it a lot more easy to fix these things. I had a friend when I was a teenager in the 80's that helped me learn to work on tv's but I never worked in or had a shop or any schooling on it, but I have had good luck getting my sets going. I am sure I can set the chassie up vertically on the floor to the way you described.

damen · #41 03-28-2010, 05:43 PM

Checked the rest of the resistors to day and replaced about 5 that were out of tolerane and all systems are go its working like a champ

thanks for the good advice guys.

marty59 · #42 03-28-2010, 05:59 PM

With your misc. issues, which circuits got the resistor replacements?

damen · #43 03-28-2010, 08:12 PM

There was a couple in the Horz circuit by the effishincy coil and a couple more in the croma, and by the 12by7 I do still see some slight retrace lines on the blank screen if the brightness is cranked up but not as bad as before. even thow the fly does not seem to be getting hot I am going to check the cathode curent next.