Decided to split this thread off, because it's going to end up taking a life of its own :)

Here's another set at an upcoming estate sale. I have absolutely no clue what it is. Center tuning knob makes me think Crosley?

Wow, that's a nice looking blonde! :-) I think maybe you are right, Crosley?

Wow, that's a nice looking blonde! :-) I think maybe you are right, Crosley?

Nope! Raytheon Vu-Matic.
They had the craziest clutch arrangement to select between the VHF and the UHF tuner.
I don't know of anyone that was able to repair them. :sigh:

Welp, I came home with it. It was marked at a ridiculous $195 at the estate sale. I figured hey, no harm in asking, so I asked if it worked. The lady said that the screen lit up, but they couldn't obviously get any stations.

I said, if I plug it in and the screen lights up, I'll give you $40 for it. It did, and I bought it. Full raster, but dim, with some bottom vertical foldover. Figured at least I'd have something to work with though. Cabinet's about as perfect as they come.

Got it home and powered it up. Raster came up, and I figured I'd see if I could tweak anything out of it. Raster started to shrink on the left slightly and it smelled as if something was heating up, so I shut it down.

Opened the back and saw a brightener. Wonderful. Removed the brightener and went to test the picture tube. The tube lit up WAY too bright on the tester and showed a dead short...so something either happened when I removed the socket on the picture tube or something's really amiss....but I shut it down fast. Not even sure what picture tube is in the stupid thing.....it's an original Raytheon tube but all the decals are missing on the inside.

Someone on the FB TV group mentioned that it should have a 21FP4, so I tested it as that, standard 6.3V filament and socket. It's a Raytheon model C2113A.

And yep, some rearranging down here is needed. Getting a little crowded lately.....

The later models used a 21YP4. The screen curvature looks like a Y.

Still the same heater voltage, and I'm all sorts of confused. I'll pull the 5U4 and power it up again and see what I see.

Still the same heater voltage, and I'm all sorts of confused. I'll pull the 5U4 and power it up again and see what I see.

I don't think, that model uses a 5U4. Selenium rectifier, voltage doubler. It uses a small heater transformer for most of the tubes. The sweep tubes and a few others are in series across the line. :D

Aw frig. I didn't look at the chassis too closely. I kind of figured I'd run into seleniums the size of toasters in this damn thing. After all, Raytheon wasn't exactly known for a quality product in the TV realm.

One of those things that I knew would be a PITA to restore, but figured that if I didn't do it nobody else would, and what the heck, at least I had a starting point.

This is the screen shot I had from last power up. Potential is there, anyway....but this one might wait for a while.

Well, it does have a 5U4, so nyah :D

This picture tube issue is weird. With a "remove shorts" procedure, the tube tests into the good range, but the H-K leakage pegs the needle. Not sure what type of picture that'll end up giving.....?

Now here's a thought.

The 21FP4 uses electrostatic focus. I believe I can use a 21EP4 which uses magnetic focus. I have a good 21EP4. Just have to rig up a focus magnet assembly.

Could also grab an isolation 'booster' and skip the modification.

Well, it does have a 5U4, so nyah :D

This picture tube issue is weird. With a "remove shorts" procedure, the tube tests into the good range, but the H-K leakage pegs the needle. Not sure what type of picture that'll end up giving.....?

Now here's a thought.

The 21FP4 uses electrostatic focus. I believe I can use a 21EP4 which uses magnetic focus. I have a good 21EP4. Just have to rig up a focus magnet assembly.
I can't believe I'm wrong again! Third time this year and it's only March 14th.
I've never ran across a Raytheon with that control panel, that had a full transformer and 5U4 chassis. :sigh:

Yup! Here's a shot of the nasty dirty chassis.....

Yup! Here's a shot of the nasty dirty chassis.....

I didn't think they built that chassis in a 21" model. It looks like there's mounting holes, for a PM focus unit.

Nope! Raytheon Vu-Matic.
They had the craziest clutch arrangement to select between the VHF and the UHF tuner.
I don't know of anyone that was able to repair them. :sigh:

YOU'RE NOT KIDDING!!!!

Check this out: https://www.youtube.com/watch?v=Z-smItbgbU8&feature=youtu.be

WTF were they THINKING ?!? Talk about Re-engineering the Wheel.... Sheesh !

Could also grab an isolation 'booster' ....
A 6.3V filament transformer would also work.

Opened the back and saw a brightener. Wonderful. Removed the brightener and went to test the picture tube. The tube lit up WAY too bright on the tester and showed a dead short...so something either happened when I removed the socket on the picture tube or something's really amiss.


This picture tube issue is weird. With a "remove shorts" procedure, the tube tests into the good range, but the H-K leakage pegs the needle. Not sure what type of picture that'll end up giving.....?


Could also grab an isolation 'booster' and skip the modification.

I wonder if the "brightener" that you removed was *actually* providing isolation of the heater cathode short :scratch2:

jr

Well, I still have it. I always keep a couple around just in case I need to squeeze some life out of a dying tube. But that's a very very interesting question.....WOULD it isolate the short?

Hm.

Some "brighteners" were not (just) brighteners. Some only isolated the heater to fix H-K shorts, some only increased the heater voltage, and some did both isolation and heater voltage boosting.

When you see a "brightener" on a CRT it pays to read the label before removal so that you know if it is on there for a good reason....

I Think the companies thast made boosters also sold isolation models. I recall seeing ads in old tv repair magazines that advertise models that provide an isolation function, and arnt actually boosters at all.

Cool tuner....

.

I Think the companies thast made boosters also sold isolation models. I recall seeing ads in old tv repair magazines that advertise models that provide an isolation function, and arnt actually boosters at all.
The more expensive Perma-Power brighteners were designed to be both isolation and boost, series or parallel. IIRC, it had four different configurations. It was twice as long as the cheaper units and had a five pin selector plug, to select boost or no boost, series or parallel. All the instructions were on the unit, to suit the application.
I might have one somewhere in my stash. :boring:

This one is an Anchor model SP43 Series & Parallel TV picture brightener. It's set up for a parallel setup.

This one is an Anchor model SP43 Series & Parallel TV picture brightener. It's set up for a parallel setup.
Antronic made them as well. If it's an isolation brightener, it would say on the unit.
I would try the separate transformer trick, as suggested by others. :scratch2:

It looks like the tuner with the high/low frequency slug tuned system. I have a TrueTone the mice loved (atop the tuner). Strange tuner if it does have it.

Antronic made them as well. If it's an isolation brightener, it would say on the unit.
I would try the separate transformer trick, as suggested by others. :scratch2:

Vid-Aire made one with a plug that selected between series or parallel filament strings, I dont think it isolated.

I had a 1958 Motorola series-heater set with an intermittent H-K short in its 21CBP4. The short made it go washed-out negative with retrace lines.
After I isolated the CRT filament with a perma-power brightner, video just got a bit smeary when it shorted.

Vid-Aire made one with a plug that selected between series or parallel filament strings, I dont think it isolated.

I had a 1958 Motorola series-heater set with an intermittent H-K short in its 21CBP4. The short made it go washed-out negative with retrace lines.
After I isolated the CRT filament with a perma-power brightner, video just got a bit smeary when it shorted.

Several companies made various types of brighteners. IIRC, Workman made a brightener for the early Sony Trinitrons. They also made one called the Super-brightener that boosted the heater voltage to 9 volts. It was used on the RCA 23EP4, that had a different pin-out. The picture looked good, for how long, was anyone's guess. :scratch2: