1957 RCA 14" model 14-S-7070 TV set

[electra225]

This set is still working on the power transformer workaround. I had never heard of that kind of a "fix" in my life, never read about it. The B+ seems stable, though. If I were to use this set heavily, like in daily use, several hours a day, surely the other half of the secondary would fail, carrying all the load. Time will tell, I reckon.....

I'd like to hotrod the paint on the cabinet. I'd have Tres make a set of decals for the cabinet, and have a saddle maker in AJ make a leather handle for it. I didn't get a commitment from Don about doing the painting, so I may tape it off and spray bomb it myself.

[Motorola minion]

This thread may encourage someone to tackle a quality project like this one. I recommend any 1949-1969 set with a power transformer like this one!

Basket cases and color TVs are best left with long-time sufferers of service (like Shang0) that are relentless until they have found all the issues. Ive been messing with curb and dump electronic finds since I was 10, when there was still value in ANY working TV for video games, forts, treehouses, etc.

Better yet, any basket case has some value when other projects need tubes, CRT, transformers and cabinet parts.

[electra225]

The main reason I tackled this project at all was two-fold. First, I wanted to actually dig into a known "broken" set, troubleshoot it without throwing parts at it, and fix it. Second, it was an RCA and so I figured parts would grow on trees for it. That was a fool's errand. This PARTICULAR RCA chassis has a wonky vertical circuit that I'm not sure if it ever did, or ever will again, work right. Getting TV parts vendors off their duffs and to encourage them to perform their self-selected duties is a struggle. I called Moyers three times, they promised to get back to me, never did. They are a joke and if that is the "go to" place for TV parts, this will be my last TV restoration. And, I learned that the advice you are given is only as good as what you paid for it. You need to have at least a basic idea of how a TV set is supposed to work before you dig in. And having the RCA service literature would have been a plus, along with a working scope and knowing how to use and how to read a scope. This could have been a disastrous project for a total electronics rookie.

[electra225]

I put the chassis back into the cabinet. I got tired of it laying on my bench. I have tubes ordered for its vertical circuit and sync circuit. I tried a different vendor for these tubes. I wanted Sylvania tubes and most of the other tube vendors wanted to charge extra for specific brand tubes. Since I am cheap, that was not gonna fly. I haven't used this vendor before. His communication is good, his service is on the slow side, typical of one-man operations. I also ordered a manual for my TV Analyzer and some other stuff he had. I thought his prices were more than fair. If I actually get what I ordered, I may recommend him here on this forum.

[William]

It is always good to have a new vendor, and hopefully he will be someone we can trust.

Bill

[electra225]

Good news and bad news.......

The good news is that I received my order. I populated both 6CH8's and the 6AW8 with Sylvania tubes and got a tad more vertical deflection. The bad news is that this set has a wonky/bad/partially, intermittently shorted vertical height control, probably unobtanium. The picture has full deflection, then it gets a black line at the top about 3/8 of an inch wide, then it gets a little wider, then it disappears. A couple of times, I completely lost vertical deflection, only had a white horizontal line. I banged on the cabinet, vertical deflection returned. I have put maybe 50 hours on this set, watching DVD's of all kinds. Beverly Hillbillies, Andy Griffith, Dick Van Dyke, a couple old movies. I tested and cleaned the height and linearity controls when I restored the chassis, and they checked good. The height control has boost voltage on it, and is obviously breaking down under operating voltage.

And, BTW, just in case anybody is interested.....Originally, this set had Raytheon tubes in the three sockets I put Sylvania tubes in, listed above. They were RCA sourced. The three Sylvanias I put in are also RCA sourced. It must be that RCA made all the 6CH8's and 6AW8's. The other tube suppliers bought from RCA then rebranded them.

I need to see if a height control for this set can even be had anymore. It has to come back apart to replace it, but I have so much time and work in this silly set that I hate to give up now. I don't know what I could have done differently to head this issue off at the pass. Suggestions? Other than the worthless Moyer's, does anyone have a suggestion where I might obtain a replacement vertical height control for this set?

[TC Chris]

Is it just a linear taper pot?

Chris Campbell

[DuckSocker]

Hey guys, sorry to interrupt.

I just bought this exact model (but mine is red) and I wanted to restore it.
I plan to replace all the electrolytic and paper capacitors, so I was wondering if you had a list?

I've found the "Photofact Folder", but they've mixed all the paper, mica and ceramic capacitor in one list and doesn't mention which is which.
And sure I could open it and list them myself, but mine is definitely in worst shape than yours and with the time the dust have mixed with the wax on the capacitors making them unreadable for the most part.
So I would have to follow the schematic to locate each caps one by one which seems very time consuming...

So if you had a list of all the paper caps so I could order them before starting my restoration, I'd be very grateful : )

[William]

Welcome to the forum, DuckSocker and you are not interrupting we are glad you found us. As far as your questions go, I will turn that over to the guys that have TV repair experience on the forum. Good luck with your project and I am glad you joined us.

Bill

[electra225]

I don't know where to start. Best thing I can recommend is to get the Sams diagram for your set and follow it. I just tossed the old caps for my set, so I can't really provide you a list. I will warn you ahead of time that this is not the easiest set in the world to recap then sort. VERY finicky vertical deflection circuit. No AGC control. The yoke is soldered in, very easy to damage working with the chassis and picture tube. I STRONGLY recommend removing the yoke rather than trying to wrestle it when separating chassis from picture tube. I don't know what your skill level is, but if you are a novice at TV repair, this is not the best set to start with. You should also have a good, working scope and a supply of tubes for substitution. Use Sylvania tubes in the sweep circuits. Every paper cap in that chassis is junk. I started working on mine with the chassis and picture tube still together, a fool's errand.

The reason I recommend you to get the Sams and follow it is that they made running changes go these sets, probably to fix the finicky vertical circuits. Yours may not have the same values as mine has. You might also use some Windex on a rag to see if you can remove the dirt and be able to read the values. The values are under wax, so getting the dirt off, gently, should not remove the values on the caps. If you can't read the value, refer to the schematic, the best way in any case. Check every resistor in the set, particularly in the vertical deflection circuits. Sorry I can't be more help. Good luck with your project and be sure to share it with us on the forum. Welcome to the forum!

[DuckSocker]

Ah!
Thanks anyway!

Actually that's my very first "tube CRT", but I've worked with CRT from the 80s, 90s and 2000s (even one of those gigantic widescreen CRT).
I've also already restored tube radio, multimeter, amp, etc.

So I'm very aware that every paper caps is junk and probably most of the resistors too.

I've also already removed the yoke and picture tube (had to find out by myself haha)

And yeah... I was hoping that I wouldn't have to find every cap one by one but I guess I'll have to do it...
I took a couple of picture to better illustrate my problem:
https://i.postimg.cc/qr1pJMgg/Caps-01.jpg
https://i.postimg.cc/NYVYXJ6c/Caps-02.jpg

And here's a screenshot of the "Photofact Folder" list I've found:
https://i.postimg.cc/Fst2B6pk/Caps-03.jpg

Sure I understand that logically C3 must be 0.001Uf and therefore either a Mica or Ceramic cap, but why not just mention it?
The fact that I have to "guess" each value is kinda ridiculous...
Also what about the voltage?

Anyway, wish me luck!
I'll make sure to update you guys, but that'll be a very long project, haha.
Actually I also bought an "Admiral T-103" at the same time and it's in MUCH better condition so I'll probably start with this one.

Oh and btw, the plastic "yoke cover" on both my 14-S-7070 and the T-103 is broken just like yours was, so I'm pretty sure those cover are broken in every single 50s TV.

[electra225]

I made it easy on voltage values on caps. With the exception of the high voltage caps, such as the boost filter and that, I used all 630 volt caps. I think the boost filter on that chassis is 1000 volts and the vertical has a .001uf @ 1600, and the audio has a 1600 volt cap as well. Tiny value caps are either mica or ceramic. You won't need to mess with them. There are several paper caps in that chassis. I left the HOT, damper and HV rectifier out then ran the chassis without yoke and CRT like a radio to test the front end and audio. I did this so I could check the operation of the horizontal multivibrator before I stuck the chassis back in. After you get the chassis and picture tube separated, the chassis is not bad to work on. Be careful working under the shield for the IF strip. You can do more harm than good messing around in there......

I made my yoke cover out of stuff I dug out of the trash at the store. The plastic is the lid from an expensive brand of ice cream. The cardboard came from rolls of industrial toilet paper. I can be more specific if that will help you.

And just as an aside, passing along good advice I was given....

Use orange drops in the sweep circuits. The "little yellow caps" that we all use for radios will be fine in the front end. But for the boost and sweep circuits, these don't hold up as well as the orange drops. For what it's worth.....