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 Post subject: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 3:31 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Hi,
I just picked up an RCA 8-PT-7010 on ebay. The seller said all he coould get out of it was some static sound. It was shipped out today, and I only live 1 state from the seller. I hope to have it by Thurs, and I can't wait to get started on it.
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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 5:54 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 4294
Location: Woodinville, WA USA
This article has some restoration notes on that model:

http://antiqueradio.org/rca16.htm

Enjoy!

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


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 6:32 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Phil, Thanks for the article. I just skimmed over it and really enjoyed it. When my set comes in, I'm going to thoroughly read it again detail by detail, so I hopefully won't make any mistakes. I'm glad you put in disassembly instructions too as well as the issue about the 6CM7 and 6CG7 tube. When my set comes in, I'll see what tube my set has. I just ordered a Sams for mine.
Doug


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 7:20 pm 
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Joined: Jun Sat 04, 2011 6:09 pm
Posts: 70
Location: shasta lake ca.
thi is a real nice tv, I have two of them, I restored one and one for parts. it is a compact tv with a power transformer and kind of a bear to work on but they work well. I used phils info from his web site to restore mine and a few others that he has restored on his site. good luck. Bill.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 11:46 pm 
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Joined: Mar Thu 12, 2009 2:20 am
Posts: 1072
Location: Dayton, OH
http://www.mediafire.com/dholland

And the service manual for your reading pleasure....

Cheers....

David


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Tue 02, 2011 11:54 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Hey, thanks for the advice and manual. I am not the most meticulous person in the world with a soldering gun, so I'll have to be extra careful on this set since it is so compact. I'd rather work on a much larger chasis, but I'll just take my time. About 20 yrs ago I bought a Sony 8-301W at an antique shop which worked a little but needed a good restoration. I've never attempted it due to the compact size. Plus, everything I've ever tried to work on solid state, I've blown up!


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 2:40 am 
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Joined: Aug Thu 07, 2008 1:36 pm
Posts: 2299
Location: Orlando
they are really not that bad, very well engineered, and have a very good sound as well.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 3:02 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Hi, the set arrived about an hr ago. Since the seller said all he could get was some static sound, I went ahead and plugged it in. I got nothing. I had already printed out the servicer manual (Thanks David) and just printed out Phil's link (thanks Phil) which I followed to a T about disassembly. Actually, it doesn't look as hard as I first assumed. I'm getting ready to start replacing the electrolytics, then I will go from there.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 3:07 pm 
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Joined: Mar Thu 12, 2009 2:20 am
Posts: 1072
Location: Dayton, OH
Let us know how it goes.....

I've got one sitting on the shelf that (allegedly) loses HV/picture after it warms up. Haven't gotten around to looking at it....

David


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 5:14 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Well I got into the set today. I replaced one electrolytic and several paper caps. My tube checker said the 1V2 was bad, so I replaced it. Still nothing. Then I happened to turn the ser over on it's side and noticed one of the tuner 6U8 tubes was missing. Imagine that! Putting in a 6U8 gave me very weak & distorted audio with the volume control about 1/3-1/2 way up. Turning it up further makes the sound disappear alltogether. Still no raster yet.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 6:18 pm 
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Joined: Aug Thu 07, 2008 1:36 pm
Posts: 2299
Location: Orlando
I restuffed the old can (very little space) mutisection cap.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Wed 03, 2011 11:16 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
I did learn one lesson already on this set. Markings on paper electrolytics do rub off with age. I one I replaced looked like it said 5mfd @ 50V. The voltage marking was wearing off. I was all set to put in a 4.7 @50v when something said "power up the set and check the voltage across the old unit." I did and got about 290V. Obviously the old unit had said 450V instead of 50V.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 12:03 am 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Some success: I have replaced about 3/4 of the paper caps. That gave me perfect audio but still no raster. I then replaced the 2nd tubular electrolytic, a 60mfd @ 160V. That brought it back to life. I now have a sharp, almost perfect pic. The only problem is the vertical hold is somewhat unstable. I only left it on for about a min because I haven't replaced the main electrolytic can yet. That's coming next as well as the rest of the paper caps. From what I've see so far, this set impresses me. Good sound and pic in such a small set, and it's been relatively easy to work on too.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 1:30 am 
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Joined: Apr Fri 21, 2006 12:49 am
Posts: 9232
:? Are we talking about the same set here??
I've had bad luck with these sets. Not great reception, poor contrast, and, fair volume at best...
May I see a picture of it playing?
Thanks.
Bill Cahill

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PLEASE visit Tube Radio Forums-The best forum in the World!


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 1:26 pm 
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Joined: Aug Thu 07, 2008 1:36 pm
Posts: 2299
Location: Orlando
they are great little sets, the one I worked on was easy, GREAT sound, perhaps the use of a ratio detector rather than a gated beam detector. Does the vert want to roll one way (like you are out of adj) or can you roll it both ways just not a solid lock? if its not a solid lock but you can roll it both ways I would look a the integrater network which I think is R153/C151 and C154. if it want to roll one way R151. C156 looks like a stressed cap as well. if you have a scope wave form 7 should tell you if you are getting a good vert sync output. V102 and V103 would be suspect.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 6:43 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Update: I've gotten 3 of the 4 sections replaced in the main electrolytic can as well as almost all of the paper caps. Vertical hold now impossible to lock in pic. The .022 of plate of 6CG7, .033 off grid has been replaced at 1 time with orange drops. i guess they're still good. I replaced 2 paper capacitors (.0056, .022) and 2 resistors 39K and 100K in the vertical hold circut but didn't help. I also tried another 6CG7 as well. Voltages on the tube are ok. I'll keep digging

Bill, I took a pic of the set out of the cabinet playing, but I think my cell phone is dying as it won't let my upload it to my computer. I'll keep trying and eventually get you a pic.
Doug


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 7:02 pm 
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Joined: Aug Thu 07, 2008 1:36 pm
Posts: 2299
Location: Orlando
I dont think those caps are the ones in the intgrater check C151,154 and R153. does it roll both ways with the vert hold?


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Fri 05, 2011 11:19 pm 
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Joined: Mar Wed 30, 2011 5:37 am
Posts: 875
Location: GA
Yes, it does roll both ways. Just can't get it to lock in.


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Sat 06, 2011 12:36 am 
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Joined: Apr Fri 21, 2006 12:49 am
Posts: 9232
Sync circuit problem. Not vertical.
Bill Cahill

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http://www.tuberadioforum.com/
PLEASE visit Tube Radio Forums-The best forum in the World!


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 Post subject: Re: RCA 8-PT-7010 Coming
PostPosted: Aug Sat 06, 2011 1:04 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 21715
Location: Detroit, MI USA
Yes, possibly a weak/missing sync pulse. If it rolls both directions but won't lock that is usually proof that the oscillator and output stages are working properly, but the sync pulse either isn't getting there or isn't strong enough to lock the oscillator.

The next step would be to look at the vertical sync pulse with a scope and see what is going on. That will narrow down where the problem is.

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Dennis

Experience is what you gain when the results aren't what you were expecting.


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