who hoo got it, I just kept adj the bottom slug, keeping an eye on the freq counter, as I approached 15khz if finally popped in. It just required a LOT of adj several turns out. Its not easy to get to so I doubt it suffered from screwdriver drift....

finally some pics

Dave, nice work.

I'd like to find an 1948-49 RCA, but all I find locally are later 50's RCA's. Some day one will show. I'm not familiar with Slick Plate?

got it at graingers, 10$ for a 12oz can, you can buy online as well. Just mask off around the anode, tape the face off, put a big roll of tap on the neck (easier than trying to mask off the compound curve of the neck/bell, and spray away after a good cleaning of course.

For best results, you should align the horiz osc slugs following the directions in RCA service data. Use a scope and make one very slight modification to the procedure. They tell you to make the highest part of the hump and the point even with each other. In reality all the old timers figured out it has much better stability and noise immunity if the hump is just slightly lower than the point, and I mean just enough lower that when you put a straight line across the scope you can barely see the difference in them.

I don't have the service data, but have a way to get it so will look into it.

I put the 12LP4, video is nice and clean but the audio is terrible, very weak and bad buzz when graphics come on. Plus you have to be tuned the the extreme end on the fine tuning to get it at all, The amp it self seem weak, got a hum when touching the center of the pot but not as loud as I would expect. The contrast was weak as well, I suspect my output from the video detector is just low keeping the contrast weak and the limiter in the audio from working properly (not a ratio detector). also real bad on the vert retrace lines, again prob due to the relatively weak contrast, plus the circuit has no vertical blanking (I may add via a RC off the vert out) which I presume is just due to the old age of the set.

It's rough to get the sound acceptable on the old RCA's, although they work much better than you describe after a proper alignment. Sync buzz on high white level like lettering is pretty much impossible to completely eliminate. Using a 6AV6 instead of a 6AT6 which some sets had originally gives a little more gain, but not a lot. They are marginal in the sound department when everything is right.

I don't even bother, just run a shielded cable directly to the high side of the volume control and run the audio output from a DTV box or DVD player directly to the audio amplifier, pull the 6AL5 and it is good to go. Works 100% better than it is possible to get even when aligned right. Some RCA's already have a phono jack on them that serves the same purpose just need to change one wire so it is tied to the volume control when using TV function.

Very easy to add blanking to the early sets. A worthwhile improvement. With blanking and direct feed for the audio, you can actually stand to watch these sets.

I had the volume on the box turned down

here is the new dag I put on with the slip plate brand graphite paint

Picture looks great, so does that dag.

yea its getting better as I play it. the RF tube (6j6) is pretty flakey, I will need to do some more pin cleaning there, if you touch it the pic will go out, very sensitive. The tuner looks like it was designed to with stand a EMP weapon, it has a LEAD shield on that 6J6. Over all a pretty well built set, but for the wafer sockets, man I hate those things. I still will need to adj the horz properly as it needs to be about 3/4 to the right for solid sync between channel changes on the tuner. I assume when properly adjusted the phase will just shift side to side and pretty much hold sync through out the control range, at least that is how it was on another old set I just finished up on (capehart with a 21FP4)

ACtually, 6J6 is oscilator.
Nice picture, and, good job on dag.
You may run into more failures on that B+ resistor.
ONce one fails, it's only a matter of time. Hope you didn't put new one accross old one.That could cause you trouble.
I'm gathering parts for my radio-tv comb. set. May get back on that before too long.
Bill Cahill

yea, I spoke too soon on it being an RF amp, just seemed like one based on size.

the power resistor section that I replaced was taken out of the circuit. there were two unused term on a nearby strip. I will need to install a strip for the remaining 650's but so far they are holding up, but I know they will fail, I saw a brief arc on one of them already.

I am really impressed with the fine details the set is producing, MUCH better than my motorola of the same era. I can see using this set as a daily watcher.

The cabinet is bakelite, no crack but the finish is very ruff, not sure how that happens, but its like 60 grit sand paper in lot of spots.I assume the blankets inside are asbetos so I need to steer clear of them.

Maybe take a look at the horizontal adjustments on one of older RCA schematics posted over on the ETF site. I'm guessing RCA used a very similar horizontal circuit in all those early sets.

I didn't know that model came in a Bakelite cabinet.

Can you actually get a resistance reading across that dag coating, or is it way up there in the mega ohms?

Actually, I think it's wood grained metal.
Could be wrong, though..
I have to get my T-100 playing again, as well as my 9T246.
Still pondering my 630. It's a mess, but, repairable....
Once, I had audio on it, but, low hv.
Then, things started failing. Like resistors in power supply. It's been downhill from there.
I'll get back on it, someday......
I am still looking for resistors to finnish vertical problem in my 6T74.
Just coming around the bend on my 16" Admiral.
Sorry for messing up your thread.
Bill Cahill

Nope. Dag coating is for added capacity to filter hv.
Bill Cahill

Correct, but I assume it needs to have fairly low resistance in order to do it's job. I know on some sets the only connection is a spring wire pressing against the dag. I'm just curious if the stuff from Grainger conducts like the original. The original coatings have only a few hundred ohms resistance across several inches of the dag coating.

To the best of my knowledge, it would check more like a capacitor.
If you ground one end of a mylar cap. that doesn't make it low resistance.
Might be different on coating, but, I've never tried to find out.
Bill Cahill

Partly depending on size of tube, it's equivalent to 250 pf, approx.
May be low resistance, though. Never tried to find out......

surface coat of dag is in the hundreds of ohms, depending on how far apart you space the meter probes. that was one of the 1st things checked, I too was curious about the conductivity of the coating, will need to compare that to orig dag.

the cabinet is NOT painted metal. it is Not wood. I am guessing bakelite since that is about the only thing left.

for fun I checked the capacitance of the CRT, used both a hand held DMM and a old school cap tester. DMM 1.2nf or .0012uf
old school was odd I got a def null reading on the eye at .001 in the .001-.5uf range, but could not get a clean open eye in the .00001-.005uf. I do have another 12LP4 that IIRC has intact orig dag so I will check it out later for comparison.