I picked this set up today. It uses the 16GP4 metal tube, but I just tested it, and it hasn't leaked it's vacuum yet, at first it was barely moving the needle at all though, but after I put it up to 8v it started to come back, so I think it will be ok. This set has most of the often missing stuff, back, hv cage top, knobs, except for the tuner knob which I don't think is original. It uses a big 10" speaker, too.

Kewl score Adam !

Was that the TV that was on craigs list in another thread where the seller suggested turning it into a aquarium ?
Either way im glad to hear a nice old set has a good home .

That CRT sounds like a job for my beltron. It's worked miracles on two dead CRTs now and they're still going strong. The machine is in no way harsh to the gun like most rejuvenators.

Perhaps some weekend I can drop by with it and we can give it a shot.

First, you need to reverse the direction of your focus magnet assembly. It's upside down. The focus adjustment belongs on othe side. Picture tube is also in the wrong direction. The 5 main pins belong on the other side, and slightly downward. There are other issues as well. If you'd like help on this set I'm willing to lend a helping hand....I've had alot of experience with this series of sets...KCS47.
Bill Cahill

Here's how the back of it should look. Bill Cahill

http://i18.photobucket.com/albums/b122/55Bill51/RCAVictortv6T74rear.jpg

That CRT sounds like a job for my beltron. It's worked miracles on two dead CRTs now and they're still going strong. The machine is in no way harsh to the gun like most rejuvenators.

Perhaps some weekend I can drop by with it and we can give it a shot.

Might be worth a try, I find if the crt is weak beyond a certain point, even if a set is otherwise working, I never watch it, I have a '54 Westinghouse with the 21YP4 like that. Have you ever tried that beltron on any electrostatic b/w tubes, I've wondered if it was possible to rejuvinate those?

Kewl score Adam !

:thmbsp:

Was that the TV that was on craigs list in another thread where the seller suggested turning it into a aquarium ?
Either way im glad to hear a nice old set has a good home .

It's the same set.

Here's how the back of it should look. Bill Cahill


Thanks, I'll turn it around when I have the chassis out.

Have you ever tried that beltron on any electrostatic b/w tubes, I've wondered if it was possible to rejuvinate those?


I may try that next :D :yes:

I finished recapping the set, and tried it out, only to have first a dim raster with the horiz frequency way off, then an intermittent bright white raster with greatly reduced horiz width. The sound worked on a few channels. Then I heard some not-too-good sounding noise comming from the chassis, and I looked around back and saw it was comming from the damper tube which was glowing bright red. I unplugged the set, and as I didn't want to run it anymore under those conditions, I put the chassis back on the bench and poked around with the ohm meter. I found 3 problems.

1. The horiz hold pot itself, when I turn it (or sometimes even when I don't) with the ohm meter on it, it jumps erratically, and when I tap it with my finger, it reads completely open. I tried spraying some cleaner in there and turning the control a bit, and no difference, it needs to be replaced.

2. The flyback: it's supposed to read 250 ohms across it, it reads 600 ohms.

3. The HV filter capacitor 250pf 20kv, it's not even there:no:, I don't know how I didn't notice this one before.

At least the 16GP4 is good.

update: I got my new horiz hold pot, flyback, and doorknob cap, I'm about to start back in on this one, I'll let you all know how it goes after I get all that stuff installed...

I pulled the old flyback out, it turns out it wasn't bad, it just wasn't the right one for this set, according to the sticker on it, it's supposed to read 90ohms-480ohms across it, Stancor A-8131, I don't know what set it's supposed to go to, but I took a pic. I also took a pic of my new RAM X124 sitting in there not hooked up yet, you can see on each side of it where someone previously working on the set drilled two holes to mount the other flyback.

That flyback wasn't even close... Your second is alot closer.
Other correct replacement is a Fly-45.
Check your lin. coil.
Thoroughly clean dirt on both sides of that fibre board, or, you are inviting arcing.
HV cap should be 500pf 20KV, Correct hv is about 13KV.
Bill Cahill :yes:

Here's pics of the new flyback and doorknob cap installed.

On that cap, the sams gives the capacitance at 250pf, so that's what I got, this replacement unit is 30kv, so it was a bit larger than the original, I had to widen the hole it sits in a bit and bend back the clips it hooks on to to get it to fit.

Linearity coil checks out ok.

Well, the lin. coil checked ok with the ohm meter, but it smoked when I plugged the set in, I'll check tomarrow to see if any of the ones in any of the junk chassis I have around here are interchangeable.

I pulled the chassis, and that coil still tests good, but it must be bad, when I turned the set on I lost HV almost immediately and then the coil started to smoke. Now I have a 730TV parts chassis and according to sams both the 730TV and the 6T65 use part # 71449, but it lists the 6T65 coil as 30ohms, and the 730TV one at 36ohms, but I think I'm going to try swapping the coil from the 730TV parts chassis tomarrow anyway. If the 730TV one won't work I also have a T-100 I'm probably going to eventually part out although I didn't yet look to see if that uses the same coil.

You'd better check your new 630 volt capacitors. They can't handle the high pulse. The originals were 1,000 volt, and, it needs that in all critical areas. That is damper, horiz., and, vertical.
I suspect one of your new caps broke down.
Bill Cahill

Those caps even though they don't look it, actually are 1kv. I pulled that lin. coil out, and after looking at it more closely I could see that it was undone and then someone had tried to rewind it, I'm pretty sure there's problems with it. I swapped in the coil from my 730TV parts chassis. Then I checked all the horiz circuits to make sure they matched up with the schematic, after that wrong flyback and this coil I wanted to be sure no one messed anything else up. I didn't find anything, but I checked each resistor as I went, didn't find any that I think would be causing my problems, but am replacing any that were more than 10% off anyway.

When I tried it out, I very briefly got a vertical line down the center of the screen, then no picture at all, and an awful high pitched noise comming out of the speaker.

I checked the horiz osc, HO, damper, and HV rect. tubes again, all check out ok. I pulled the yoke, and after having the wrong fly in here I'm not sure if it's the right yoke either, resistance readings aren't too far off from where they should be, but there's that resistor in there in series with the vert. coils that doesn't appear on the schematic. Here's a pic.

What is the number on the yoke?
You have a failed horizontal section. Could be the yoke, but, it sounds more serious.
Bill

If someone put in a yoke that matched replacement flyback, then, it's the wrong one for the set.
Bill

The fuse between the +370v source and the lin coil blows whenever I plug the set in, and if I try it with the fuse bypassed I get what I described earlier (I didn't leave it on for more than a few seconds), and if I try it with the fuse blown, I get no HV as would be expected, but I also don't get that high pitched noise. I'm thinking something is drawing too much current and blowing that fuse, but I can't figure what. I can't find any shorts to ground, all tubes test good, new caps, new fly, the yoke is all I can think of that's left. Although I wouldn't think a mismatched yoke, unless there was actually something wrong with it would be doing this either. I couldn't find any numbers on the yoke. One cap I haven't replaced, but might try next is that 4.7pf cap hooked between the plate of the HO tube and the yoke, it's not shorted, but I don't have a capacitor tester on which I could check it any further. Becuse it keeps blowing that fuse, I don't really want to leave it on long enough to take any voltage readings, in case it damages my new flyback or other parts.

It seems like my TC-127 had a wire that came from the power transformer and led to the fuse in the HV cage. I wonder if a shorted section in the power trans. could cause some of these symptoms. If memory serves me right the power transformer supplys a separate voltage to the damper tube. I want to say it was heater voltage but most of the dampers were 6.3 volt 6W4 or 6AX4 I think back then, same as the rest of the string minus the LV rectifier, so I may be off on this.

Also my TC-127 has a different chassis but a lot of that period RCA chassis were similar in setup. I am fairly certain this threads set would have the supply from the transformer. Just trying to help.

After nearly a year passing on my RCA restoration I have found enough needed tweaks to warrant chassis removal again. The sound is very low, sometimes the picture has a bit of vertical jitter/jumping and the vertical size shrinks just enough to make you want to try to adjust the size and lin. controls which are cranked all the way. I'm thinking resistor issues on nearly all of this and a possible cold solder joint from the recap. Actually truth be known there are still two or three of the fake mica caps that are actually paper left in my set. They get overlooked a LOT as caps that have a low failure rate but are in fact unreliable paper caps with the same color dot code and look as the longer life micas.

In my stupidity I left a few fake mica's in my set knowing what I just told you all. Still in all I was more than pleased with the results I got with this set. These sets offer a SUPER crisp picture I think....

The power trans does have a seperate winding just for the filament voltage on the damper tube (6W4)

Yes, and that winding is not grounded. It is insulated at 2500 volts because RCA put the cathode on the filament to prevent arcing.Arcing was a big problem with those tubes. If the winding is leaking to the chassis it would cause a short in B+, which would blow that fuse, and make alot of other stuff un happy until it does. Bypassing fuse is very bad on the flyback. Not a good thing. You MUST stay with the original value .25A,250 slo blo fuse. Clips can be had to adapt the new fuse to the old pig tail fuse.

Looks like you are past the guess it could be this part point. Start tracing, do resistance measurements in circuits, etc.. You obviously have a short.
Bill Cahill Get a capacitor tester for those new caps you installed. My guess still would be that one, or, more of them has failed. It only takes one to cause a short.
Try unplugging the yoke, and, put a jumper wire over the two pins that connect the 5U4 the the rest of the set.. Power it up, with a proper fuse, and, see if it still blows. If so, the short is somewhere else.. Is it your vertical, or your horiz. that failed? If it was truly the entire horiz.then, you shouldn't get a vertical line..It has to work at least a small amount for the flyback to work.. Is flyback wired properly? Did you make any mistakes in your wiring? The cloth covered wires, and, I warn you, they have damper pulse on them, that go from the damper filament to the terminal strip below that has thw cloth wires from power transformer, and, those wires, tend to fail, and, rot.
Also, I doubt your problem is that coupling capacitor. That's a special capacitor rated at a very high voltage, by the way. I believe it's rated at something like 2500 volts.
There is an extremely high pulse on the plate of the horizontal output tube.
Bill Cahill

I pulled the yoke, and after having the wrong fly in here I'm not sure if it's the right yoke either, resistance readings aren't too far off from where they should be, but there's that resistor in there in series with the vert. coils that doesn't appear on the schematic. Here's a pic.

That's not a resistor, it's a small value cap. Probably something like 47pF.

Nice set!! I am into mostly early color but I can't help but love the B/Ws. I am trying to find some '40s sets for my collection.
Mark

Thanks, nice Zenith roundie, I have 2 early color sets a 1963 Philco combo, and a CTC-10 w/ remote, I have yet to start working on the 10. Southern CA seems to be completely lacking of Zenith roundies, in 6 years of collecting sets down here I haven't seen a single one.

That is a 47pf cap in the front of the yoke, but there's a resistor over on the left side, according to my schematic the yoke should have 2 caps in it and no resistors, I'll take a good look at it and see how it's wired then post up a schematic of it vs. the one that's supposed to be in there.

Any resistance tests I make show nothing wrong with the set. I ordered .02mfd 1.6kv replacements for those .018mfd 1kv caps, (I figured the .002 mfd difference wouldn't cause any problems) I guess something could have happened to them when I turned it on with the wrong fly in there.

I swapped those caps, but that yoke is definetly not what should be in there according to the schematic I have, so I think I'm going to wait to get a yoke before I try this set again.
Now I'm on to figure out what happened to the HV in my '54 Westinghouse...

I gotta say after seeing all the problems that Adam and Bill have had with this particular model chassis I hope I never have to fix one!

On my KCS-47A I haven't had much trouble getting it going. Just the normal stuff like no sync, horz freq stablbilly, and HV filter cap bad. Haven't worked on it since holidays it got moved to put the xmas tree up.

Terry

Made some progress on this set tonight. I put in the new correct yoke, and still had the same problems as before, but noted that the 5U4 was glowing excessively bright as well as the damper tube. It turns out the filament winding for the damper tube was arcing inside the power transformer, either to the 5U4 filament winding, or main secondary windings. I had dismissed the idea of a short in the power transformer being a problem when I tested it for shorts and found nothing, but even though it's not actually shorted it appears something is arcing in there when it's working. I powered the damper tube filament off a separate transformer, and pulled up this blank raster. I still have no picture or sound, but at least I got HV.

This set sure needed a lot of new parts. The power trans must have been the original cause of this set's problems, but it burnt out the lin coil, and caused someone long ago to replace both the yoke and the fly (with the wrong ones!) and then loose the hv filter cap. At least the 16GP4 is still good (the brightness isn't up all the way in the pic)

Keep up the great work!
Dan

Thanks. Messing with the tuner does nothing, no static out of the speaker, or on the screen when I change the channels. Turning the volume control does produce some static. With both no picture or sound and the tuner doing nothing, I'm thinking the problem has to lie in the IF sections common to both. In this set the sound comes off after the 2nd IF tube, so that narrows it down a bit. It could be the local oscillator coils in the tuner need adjustment like they did on my 721ts, but with the tuner having no effect at all on the picture, I'm thinking there's something else wrong here. I'll pull the chassis later and check it out after I see if I can get ahold of a new power transformer. With 4 video IF sections this set must have been quite a performer in it's day.

There are two common problems that happen on this set of chassis' KCS 47.
1 Open resistor on 2nd video I F
2 Bad tuner.
If while changing channel selector you hear a slight scraping sound , and, or, it's acting unusually tight, the switches are badly worn, and, bent. Best to keep looking for another chassis with a better tuner.
Have you tested your tubes?
Sound does get its' take off from 2nd video I F, but, tuner uses two seperate frequencies. One carrier is for the picture, and, other is for the sound carrier.
Bill Cahill

Made some progress on this set tonight. I put in the new correct yoke, and still had the same problems as before, but noted that the 5U4 was glowing excessively bright as well as the damper tube. It turns out the filament winding for the damper tube was arcing inside the power transformer, either to the 5U4 filament winding, or main secondary windings. I had dismissed the idea of a short in the power transformer being a problem when I tested it for shorts and found nothing, but even though it's not actually shorted it appears something is arcing in there when it's working. I powered the damper tube filament off a separate transformer, and pulled up this blank raster. I still have no picture or sound, but at least I got HV.

This set sure needed a lot of new parts. The power trans must have been the original cause of this set's problems, but it burnt out the lin coil, and caused someone long ago to replace both the yoke and the fly (with the wrong ones!) and then loose the hv filter cap. At least the 16GP4 is still good (the brightness isn't up all the way in the pic)

You can easily remedy this problem of arcing.
Remove the jumper wire from the cathode of the damper to the filament pin. This removes the boost from filament winding. Then, replace the 6W4 with a 6AX4, which should stop the tendency of the tube to arc internally.
The 6W4 had a tendency to arc, so several companies, including RCA put a special hv isolation winding on power transformer, and, tied the cathode to the filament. My 6AX4 doesn't arc, and, it works fine.
You are on your way....
Yes, this seems to be a troublesome chassis.
Bill Cahill

If it makes anyone feel any better I had exellent results in restoring my RCA which again is a TC-127, but should be basically the same chassis. Really I was surprised at the good luck that I had even after frying the power transformer by being dumb enough to throw 110V.A.C. to it after only a few hours of the trick with the 100w light bulb. I lucked out on a replacement transformer to the tune of $40.

I also hace an 8T-243 which also is the same chassis design and it had power supply issues as well, although I didn't lose the transformer. Adam, make sure that when you power this thing up that the transformer stays cool. If it is getting hot than do not plug it in until you find out for sure what is going on. That bright glowing 5U4 worries me.

Also, I remember that the negative sides of the filter capacitors in the power supply do not go to chassis ground. I almost made the mistake of assuming that they would and I would be scared to think of what would have come of it had I made this mistake. It would be an easy one to make. It was a good lesson learned (the easy way) for me to realize that I need to be 100% aware of where each component connects before I assume ANYTHING.

You may want to check this yourself....

Well, actually, no. The chassis in the 6T65, etc., is nothing like the others at all..
It was a more cheaply made chassis, and, B- WAS on the chassis.
No similarity, whatsoever.
Bill Cahill

Rule of thumb:

If the electrolytic cap cans are covered in cardboard, they're very probably not at chassis ground. If they're bare metal, they probably are at chassis ground. Obvious reason, risk of shock touching the "hot"-neg cans if not insulated with cardboard.

Maybe not universal, but true in every case I've run across.

Adam's photo in post#1 shows bare metal cans. So reasonably assume their B- is at chassis ground.

Just a note of information:
RCA's KCS 47, 49 series of tv's had all B- on Chassis.
Some of the early sets don't have cardboard on one of the main filters, but, B- is above the chassis.
Bill Cahill