Another new find! jeez. RCA Victor
 

I got another new curbside find. Its a nice immaculate shape RCA vitctor floor model.

Its in a nice blonde cabinet, not a scratch or scuff on it. It has safty glass, with a 21 inch screen. Ill try to get pictures soon.

Im wondering if anyone has any sams? Gawd, I need to make money soon, I still have that one I never got a chance to work on. No funds. oh well.

The dude that found it, "just plugged it in", but he said it has sound, but no pic. So, that is about normal anyway. There is everything with it. Its got the back, and everything. It even has writing on the back that it was purchased and installed in 1956.

It even has the original rabbit ears!! (modular device).

Model: 21-d-7470, kind of hard to read. It has a delux logo on the front.

Do you mean 21D7479? The set is from about 1956 or 1957. Good find for being out onthe curb. I am certain that I have the SAMS. I will have to get the folder out to see if it is complete.


polaraman

Wanna freshen up a couple of my sets? I'll pay you, and they're shippable....

talking to me or polarman?

preliminary look over turns up this:

the damper tube is wasted. no filiment. there is no HV, no oscillator whine. (bad caps or something). It does have a metal chassis, but also has a circuit board with tubes.


The thing that worries me. The yoke i think is shot. I pulled the focus/centering magnet(no wires to it), and all kinds of black crumbly stuff came out. The yoke is falling apart. It is intact, but the end where the wires go, is falling apart. its crumbling. Its either toasted, or the adheisive has gone over the years. Maybe this is stopping HV.

Anyway, I cant test it without sams, can someone scan and post? I tried another simliar damper, and nothing. so, either the yoke is holding it, or the caps are. But again, I cant do voltage tests without the sams.

The flyback stage gets its DC through the damper so no damper operation=no HV. Checking resistance on the flyback can give you a clue as to its condition, just be sure set is unplugged/all caps are discharged.
You really will need to replace all caps to be able to troubleshoot well...its a wild goose chase with old caps in there as they cause so many problems.

The yoke has probably disintegrated due to heat on the plastic...I would just leave it alone, it should be OK unless some of the coils have shorted.

What is the KCS chassis number...we have all sams through the 70s so we should be able to scan.

This isn't a metal crt model is it? If it is watch out! as the HV connects right to the metal shell with no insulation.

no idea, how do I find this?

Also, i changed the damper, nothing, but it wasnt quite the same tube.

I still have all the original tags to it. Service tags, and the store advertising tags
LOL. they were inside.



no metal CRT, and I already pulled the yoke. The two peices (yoke and PM magnet for focus/center) have already seperated.

Well, im reading 20 volts on the plate of the h output tube. That has to have something to do with it. I used the chassis as a ground on the meter.

Also, there is no volts anywhere on the CRT socket except the filiment and about another 20 volts on the red wire.


hmm, sounds like bad ballast resistors. It has excellent sound fedelity, and im picking up channels with the internal antenna in the basement! So, its got great IF and tuner stages, so it has to have B+ somewhere.

its loosing the supply for the deflection circuits. There is no vertical out either. There definatly is no horizontal out, with a 20 volt B+, I think hardly.

The only thing I can figure, there is a shorted electro, so when someone plugged it in, it burnt the ballast resistors. (wherever they are, dunno without sams).

Gonna have to change caps, no other way around it. Back to raising funds. :scratch2:

I do not have SAMS 346. Can anybody else help out.


polaraman

Mike:

What is the chassis number of your set? The yoke is probably fine, that plastic housing often goes bad but the yoke will still work. I doubt if that chassis has ballast resistors. Some of the RCA had those long resistors that mounted to the inside of the chassis and had several taps. Perhaps one of those opened. BTW, I wouldn't measure the plate voltage on the horizontal output tube but rather the grid voltages.

Steve

yea, well, on my emerson from along time ago, I had one go bad, and it dropped my plate voltage.

When its normal, it overloads my meter.

there aint even any voltages on the CRT gun. only filiment. So, somethings up.

kcs104H
rvb274

those are stamped on the metal chassis.

RCA tv
 

Caution: DO NOT check Voltages on damper, horiz. out plate, or vert. out. plate. The hv current when those circuits are working will instantly fry your meter!!!! Yoke won't do you any good with-out the centering magnets, and rings. Replace. Also, it could be shorted. The plastic deteriates, and changes chemical values. I've actually seen this cause shorts between vert. and horizontal windings. NOT godd...... Your boost filter may be shorted. If damper was burned out, sounds suspiciously like something caused it. What was original no., and what did you use? If you e-mail me, I can help. [email protected] :)

the damper actually looks ok, its the filiment thats burned out.

I cant figure out where any of these parts are, or how they are used in the circuit till I get sams.

ok, I pulled the chassis, they made damn good use of circuit boards :(

Anyway, I found one resistor 100ohms by the color bands, it reads 4.3k ohms on the h out tube.

I found another stage, it has some unknown resistor connecting from a board off to the left, up to the deflection stage, I don tknow without sams, it is charred so bad, I cant see the color bands, as soon as I touched it, it fell apart. So, its bad. No idea what value, or where its used, no sams.


Anyone?

Well, if you need some dough, I need some repairs :)

yea, but im not very good with cabnet work. Im excelent with electronics. not so good with cabinet.

mbates can you get the kcs chassis number, it will help me find the sams.

its in the post. KCS104H

I found the bad resistor, I replaced it, it jumped from 20 volts to about 235volts, but as soon as the tubes warmed, it dropped all the way down again, and burned the resistor. Bad cap syndrom most likely.

I borrowed a DV cam with a picture ability. One is kind of hard to see, low light conditions, so I took most in nightshot. (infrared LEDs, b&W)...