View Full Version : RCA Chassis KCS88K , anyone have any info on this?


kramden66
06-18-2013, 02:27 AM
I just thought i'd ask since some of the guys here know a lot about chassis and could shed some light on it , i checked the crt and it is real good.

mike

dieseljeep
06-18-2013, 10:22 AM
I just thought i'd ask since some of the guys here know a lot about chassis and could shed some light on it , i checked the crt and it is real good.

mike

The set was RCA's first, re-design models. IIRC, it was the first RCA, to use an audio output tube voltage divider. That model was a lot simpler, than the previous models. As a result, they're easier to restore.
Yours is a UHF model, that had a cascode tuner and a better AGC circuit. They work well, when restored.

kramden66
06-18-2013, 11:51 AM
audio output tube as a voltage divider - why ?

mike

old_coot88
06-18-2013, 12:42 PM
audio output tube as a voltage divider - why ?

mike
Output stage does double duty as a B+ dropping resistor. Saves cost of a large power resistor, reduces parts count.

Electronic M
06-18-2013, 02:35 PM
Reminds me of one that is rotting about half a mile from the family cabin.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Down%20in%20the%20dumps/DSCN1020.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/Down%20in%20the%20dumps/DSCN1020.jpg.html)

Phil Nelson
06-18-2013, 03:03 PM
Similar to my family's first TV. That set logged a lot of hours over the years!

http://antiqueradio.org/MyFirstTV.htm

Phil Nelson


http://antiqueradio.org/art/RCAOriginalTV.jpg

compucat
06-18-2013, 03:10 PM
Those RCAs from the Fifties really seem to be built for long service life.

dieseljeep
06-18-2013, 07:12 PM
Output stage does double duty as a B+ dropping resistor. Saves cost of a large power resistor, reduces parts count.

Also slightly less power consumption.
All manufacturers seemed to use it alot. Just about any set that used a 6AS5, 6W6, 6Y6, 6BF5, 25L6, 12L6, as an audio output.
Also reffered to as stacked B+. :thmbsp:

wa2ise
06-18-2013, 09:24 PM
Reminds me of one that is rotting about half a mile from the family cabin.


Hell, someone over in one of the color TV forums is restoring a set almost as beat up as that one... http://www.videokarma.org/showthread.php?t=258006

truetone36
06-18-2013, 10:48 PM
That model's from 1954, IIRC. I have two of them. One's in fair shape, and the other looks like the one Electronic M posted the pic of. Both are missing the channel selector knobs, however.

Electronic M
06-19-2013, 02:31 AM
Hell, someone over in one of the color TV forums is restoring a set almost as beat up as that one... http://www.videokarma.org/showthread.php?t=258006

I wonder who that nut is? LOL.

If I had not had the misguided idea when I was around 10 years old to smash the CRT neck to discharge that lethal high voltage that was sitting there all those years:screwy:, I'd have dragged it home and started messing with it years ago..... I did take most of it's tubes though.

kramden66
06-19-2013, 03:03 AM
the one that is rotting away has a chanel selector knob , theres your chance of getting one

mike

Jon A.
06-19-2013, 03:24 AM
Hell, someone over in one of the color TV forums is restoring a set almost as beat up as that one... http://www.videokarma.org/showthread.php?t=258006
And doing a "bang up" job of it too.

dieseljeep
06-19-2013, 09:31 AM
I wonder who that nut is? LOL.

If I had not had the misguided idea when I was around 10 years old to smash the CRT neck to discharge that lethal high voltage that was sitting there all those years:screwy:, I'd have dragged it home and started messing with it years ago..... I did take most of it's tubes though.

The rusty model shown, is the slightly newer model.
It might be a KCS92, which was simular, but had 90 degree sweep and a few changes in the tube lineup.
Both models were the first RCA's to use PC boards in the IF and audio circuits. :yes:

Electronic M
06-19-2013, 12:05 PM
Funny, I don't recall seeing any PC boards in that RCA, though it is so full of leaves I could imagine not seeing it under all that.

dieseljeep
06-19-2013, 01:05 PM
Funny, I don't recall seeing any PC boards in that RCA, though it is so full of leaves I could imagine not seeing it under all that.

The audio board is in the right front, viewing the set from the rear. It's rather small containing the 6AU6, audio IF
and the 6AL5 ratio detector.
I have a KCS87, which was simular, but a cheaper 17" model. IIRC, the IF in that model is hand wired. :scratch2: