Greetings and Salutations
 

My name is Joe and I'm a 29 year old tech support operator from Georgia. I'm an electronics hobbyist and a history buff. I'm hoping to get help with my first TV project.

I recently acquired an RCA Victor Model 17-H-1, chassis KCS78C, from my late grandmother's estate. It's dated April 1953 and seems similar to the "Brent" I've seen in ads from Life magazine.

My mother says it was the first TV the family ever owned, so I'm hopeful I can get it working, though I am concerned about the condition of the CRT. The black material on the back of the tube is peeling off, and I can't find any information online that says one way or another if that is vital to its operation.

Regardless of the tube condition, I plan to recap the whole thing (the replacements are winding their way here from Canada as I write this), and then see how things go on the regular vacuum tube front, and I'll tackle the pesky CRT last. I've got a B&K CRT Analyzer/Rejuvenator 420 coming to me as well, but I'm not really sure how much help it's going to be for this tube.

It looks like you guys have a friendly community here. I look forward to learning from all of your combined experience. Thanks for your time.

Welcome aboard!

Neat old set ! The "black stuff" flaking off the CRT is Aquadaq.

Welcome
 

Nice set and even better that it has family history.A little bit of aquadaq peeling off souldn't cause any problems. I have seen this suff in pint cans in a Stewart & Macdonald catalog for guitar builders.Aquadaq is a conductive paint and in short the application to the crt's exterior creates a capacitor that will store a charge and one that can bite!. On the subject of crts i have often found that they need usage to wake them up after years of sitting idol.Crt rejuvenation can be ticky and risky,caution must be used.

Welcome to VK.
That flaking aquadag coating is conductive and grounded. That combined with the CRT glass and inner HV conductive coating forms a filter capacitor for the HV.

A little flaking is no big deal, but if big chucks come off it might be a good idea to recoat it. You can use SlipPlate of Aerodag aerosol conductive coatings.

Perhaps it can be stabilized with a clear coat of lacquer or enamel ? Just make sure not to coat the portion that makes contact with the chassis. That's the ground connection.

Thanks for all the quick and detailed responses. I had seen the term "dag ground" mentioned elsewhere, and the bit about the outer and inner coatings forming a capacitor, but strangely couldn't find any explanations as clear as what you've given me.

The most important thing is that you've confirmed that it's possible to restore it. Since some fairly big pieces have come off, I think I'll go with the recoating option. You guys have given me a couple of things to look for and that's going to be a big help.

Does anyone happen to know where I can get the schematics for the KCS78C? I have seen places selling them for the KCS78F and KCS78H, but not C. I contacted Justradios.com (which felt ironic), and they said they didn't have the schematic for that particular TV. Any help with that would be much appreciated.

Also, the volume control knob and the RCA Victor logo panel from the front of the TV are missing and I'd love to find replacements for those. This seems like a good place to ask for directions to finding those items. Any ideas?

Joe, welcome! Regarding that Sams, I see in the index that it jumps from the "B" to the "D". My guess is that one of the two versions will be close enough. I do have a spare copy of both. I can dig them out and see what some of the key differences are, maybe we can figure it out with a few questions?

1953...Lessee...What all went on that I can remember that year ? Korean "war" ended...Queen Elisabeth ascended the throne in England...They executed the Rosenbergs...Last year for the flathead Ford V-8...Automatics were becoming more & more popular...Perry Como & Eddie Fisher were popular...Ike was inaugurated...my parents were married for 3 years, I came along 4 years later, in '57...

Thanks bgadow. My own copy of Sam's Photofacts for KCS78B, after being lost in the mail for a week, showed up yesterday evening. Superficially, just looking at the picture of the underside of the chassis and the real thing, it doesn't look like much has changed. There are definitely a few extra components, I'll need to sit down and study on it a bit to see just what's different, then I'll take some pictures and come back here for help.

The topside looks identical, except that one of the tubes from the high voltage cage is oriented differently on the older chassis design. It sticks out of the cage on the old one, where as the one on the KCS78C is fully inside it.

One thing that surprised me on the schematic is that a couple of little gumball sized things I thought were oddly shaped high voltage resistors (they're color coded, they have a resistance, etc.) are actually inductors. When I think of an inductor I think of air coils, so that was definitely something new.

I got the CRT Analyzer/Rejuvenator last week and the 17QP4 tested bad. I let it warm up for about four hours, and it didn't climb out of the red. I ran it at 8V instead of 6.3 for about an hour, then did the remove shorts option a few times and got it up to the line between red and green. I figured what the heck and did the dynamic rejuvenate and got it up to a couple bars into the green. It's still not very good, and no amount of additional warming up or short removing seems to be able to get it any higher, but I am hopeful that I'll at least have something to look at after (if) I get everything else working.

While I wait for the capacitors to come (the next time I order parts from Canada, I'm going to pay the 2 extra dollars for air mail), I'm reading "Television and Radio Repairing" by John Markus. It makes me feel a little sad to read how optimistic the author is about the future of TV and radio repair, after seeing the thread on here about the death of the TV service business. Even though he highly recommends it and even gives examples, I don't believe I'll be rushing to produce business cards for my budding TV business anytime soon.

Based on the lack of response to my want post in the classifieds section for a volume knob and RCA Victor logo panel, I'm guessing these are unobtanium?

The panel (what they call a "pencil box" door) You'll need to keep asking around. You could also ask on the TV forum section over on Antique Radio Forum. Somebody's got one somewhere. Ditto on the knob. Find a good picture of the door and knob and post it. You could also send the knob picture to Mike Koste of Gobs of Knobs and he might have one. His handle here is ekimetsok.

There is a fairly good chance that I have a knob, but I would need a good picture of what you need to compare it to. It's always a pain going through the stash of knobs-I've got hundreds of them, and always have to dump them out on the floor to really find most of what I'm looking for. Those pencil boxes do turn up; probably a few different styles that would fit. Got to be somebody out there parting one out.

Thanks guys, I appreciate all the help. I'll try to find a good picture of the knob and get back to you.

This just turned up on the 'bay might be what you need?

http://cgi.ebay.com/VINTAGE-RCA-VICT...item35ae916c98

not affiliated,
jr

Thanks, that just might do the trick. I've written the seller to ask for the dimensions to make sure it would fit.

Another member PMed me last night about a possible replacement knob. Things are coming together.

UPDATE: I got the new volume control knob from Tim here on the forums. It's a perfect fit. So that's one piece down. The pencil box cover on eBay proved to be too big for my set. I'm keeping an eye out for another. For the moment, the TV is on hold because I'm fixing up a Capehart-Farnsworth CK-93 radio/record changer. I've got the radio back in good order and now I'm working on the changer. As soon as I finish with that, I'll tackle the TV. I've finished Television and Radio Repairing, and now I'll read Advanced Television Repairing and hopefully will be better prepared by the time I'm ready to get to work.