Rca 9-t-79 - Videokarma.org TV - Video

miniman82 · #1 09-24-2011, 12:42 AM

This is the chassis and 19AP4D from one of the prospective cabinets for the color prototype, I couldn't resist stuffing some caps in it just to see what it would do. Looks like it would be a very good performer if given some more parts, perhaps I should hang on to it? Vert linearity is very poor, probably some drifted resistors/lin pot or the degeneration cap from the cathode of the vert tube. Only bad tube I found was one section of the 12AU7 video amp, replaced it and it's good to go now. Took a total of 3 hours to get it this far, the original lytics formed up perfectly running cool as a cucumber for longer than 30 minutes.

Sandy G · #2 09-24-2011, 04:43 AM

Like the 2nd pic-"Squeal lahk a Peehg, Boy..." (grin)

*Bill Cahill* · #3 09-24-2011, 06:22 PM

Looks like set is worth saving. Needs re capping.
Bill Cahill

Phil Nelson · #4 09-25-2011, 02:14 PM

That looks mighty good after only minimal work. The linearity should not be hard to bring into line. I'd be tempted to fix & enjoy, and look elsewhere for a cabinet donor.

Phil Nelson

miniman82 · #5 09-25-2011, 03:06 PM

I'm cursed it seems, every time I find a set it's in such good condition I can't bring myself to hack it. lol

Most sets that use metal cone tubes seem to have very poor or no emission at all, whereas this one has a practically new tube in it. I'll try a few more lytics, then power it up again.

wa2ise · #6 09-25-2011, 04:22 PM

Quote:

Originally Posted by miniman82

I'm cursed it seems, every time I find a set it's in such good condition I can't bring myself to hack it. lol

You know the drill, replace only one at a time, and test the set after a few. The wax caps in the vertical section once replaced should get the linearity better.

Glenz75 · #7 09-25-2011, 04:34 PM

Amish is probably hoarding a house full of rare vintage TV's and prototype RCA's...Thats why he's grinning!

kvflyer · #8 09-26-2011, 09:21 AM

Well, that is an "unfortunate" situation to be in

. Now, what to do???

dieseljeep · #9 09-26-2011, 10:11 AM

Quote:

Originally Posted by Glenz75

Amish is probably hoarding a house full of rare vintage TV's and prototype RCA's...Thats why he's grinning!

The Amish don't believe in radio, TV's or electricity, or in dentists and barbers either.

Kevin Kuehn · #10 09-26-2011, 11:20 AM

Quote:

Originally Posted by dieseljeep

The Amish don't believe in radio, TV's or electricity, or in dentists and barbers either.

Ahh...I know an Amish family that keeps their meat in an electric freezer across the road in their neighbor’s garage. What "they" believe is that they are not allowed to have one on their property.

Electronic M · #11 09-26-2011, 12:17 PM

I hear that some Amish have built "phone shantys" on their property.

Electronic M · #12 09-26-2011, 12:24 PM

Quote:

Originally Posted by miniman82

I'm cursed it seems, every time I find a set it's in such good condition I can't bring myself to hack it. lol

Most sets that use metal cone tubes seem to have very poor or no emission at all, whereas this one has a practically new tube in it. I'll try a few more lytics, then power it up again.

Nothing to feel bad over when you want to save something you ain't into that is in excelent condition, but when you start wanting to save junk (as I've felt compelled to do from time to time) then you should step back and carefuly question your sanity....

Might make a nice set to watch monochrome stuff on.

Tom C.

Glenz75 · #13 09-26-2011, 09:51 PM

Whoops... I made an assumption there...Yeah now it clicks..sorry

Quote:

Originally Posted by dieseljeep

The Amish don't believe in radio, TV's or electricity, or in dentists and barbers either.

miniman82 · #14 11-21-2011, 02:21 AM

Decided to stuff the parts back in the cabinet, since I'm more or less done with the recapping. There's still a vert lin issue I haven't sorted out yet, I think the resistors in the vert output cathode circuit are douched up or something. When I first got everything installed, vert height was way too short. Turned out to be a resistor feeding the oscillator from B+ that had drifted 120k too high. No biggie, replaced the resistor now there's plenty of height. The slight tearing at the top turned out to be a sync issue, because I didn't have any .47uf caps in the inventory. One is at the sync amp cathode, the other goes to the sync sep. Gonna be real nice once finished, I really like this set.

miniman82 · #15 11-23-2011, 11:38 PM

Tried hooking it up to the cable box, and hmmm....no audio.

Speaker wasn't blown and the output tranformer seems fine, so the circuit must not be getting powered. Sure enough, 5 minutes of poking around revealed that a 470-ohm power resistor feeding the audio output tranformer had opened up. I don't have a replacement in this value, so I'll have to order one or something. I'm sure that once it's replaced, audio will come back to life.