24 inch Muntz restoration has begun
 

Hi Gang,

Last Saturday I was able to pick the 24 in Muntz. I started tinkering with it on Monday. First order of business was to test the crt. The 24ap4 was still under vacuum. The crt is a rebuilt replacement. I put my B&K crt tester on it and all I could get was a crummy reading of 250 on a scale of 1000, where 200 is the cutoff between good and bad. After about an hour of warmup with no improvement I started to gently restore it. After working carefully I have achieved a solid 420 which I think will yield a watchable picture in a subdued lighting environment. With a brightener attached I get a solid 800. So if need be I can always go that route.

Next order of business was to fire up the chassis. I got sound but no picture and no high voltage either. So I shut it down and proceeded to carefully remove the chassis which has the 24 inch crt mounted on it. WHAT A MONSTER CRT. If you look at the rear view of the set with the chassis inside you can see that the crt occupys most of the cabinet interior. The crt is huge.

After I got the chassis out I carefully removed the crt from the chassis and put it aside.

Here is a tip I got from John Marinello on removing the crt. I have always had a bit of trouble with the crt socket hanging up on the focus or deflection yoke when sliding out the crt out. John said to tightly wrap a piece of paper around the end of the neck, covering the socket and the glass and tape it in place. That way when you slide the crt out, the lip of the socket can't get hung up on the inside of the focus and deflection yoke. thanks for the tip John, it works great.

So now I turned over the chassis. I was just appaled at the crapy repair work that had been performed on this chassis. All sorts of jury riged repairs including resistors that were just wraped around wires without even soldering. Several caps were completly drained of wax and you could see the foil bundle inside the cardboard tube. At some point the verticle output transformer and the deflection yoke had been replaced.

So Tuesday night I started recaping the old beast. I finished tonight. Then I installed my 5 inch test crt for the big test. The big question....will it work?...will there be high voltage?....will there be a raster?.....will there be video and audio?.....

YES!!!!!!! TO ALL OF THE ABOVE.

After a few adjustments and replacing a few weak tubes, I got a half way decent picture. I will leave further tweeking until after I have the 24 incrt installed and the chassis is put back into the cabinet.

A couple of oddities about this set....there is no HV cage, what you see in the photo below is what you get. You can't operate the chassis without the speaker because they have a power supply choke mounted on the speaker, and the audio output transformer is mounted on the chassis. Very wierd. In the photo of the set with the doors open, you will see what looks like a pencile box door that you would expect to find operator controls behind. But the door is not hinged, it clips on with some clips and comes completely off to access the controls. And the controls behind that panel dont have any knobs, just bare control shafts. Muntz was truely the king of cheap. The tuner dosent even have any fine tuning control. Talk about no frills, this set never heard of frills. The only controls on the front are on/off/volume, and contrarast, on the left, and the chanel selector on the right. No agc adjustment on the chassis either. I does however have horizontal linearity, (which some of my Zenith portholes do not have)

I will post additional pictures of this monster after it is completed. Until then these photos below will have to serve to wet your appetite.

Enjoy!

http://www.audiokarma.org/forums/att...1&d=1189662677

http://www.audiokarma.org/forums/att...1&d=1189662677

http://www.audiokarma.org/forums/att...1&d=1189662677

http://www.audiokarma.org/forums/att...1&d=1189662677

http://www.audiokarma.org/forums/att...1&d=1189662677

http://www.audiokarma.org/forums/att...1&d=1189662677

Good grief, that chassis is bare bones!
The little 8" RCA's have more parts than that!
Kinda surprising the Madman used a transformer instead of a voltage doubler power supply.

That set really lives up to the madman's cost cutting reputation.

Well, I can see why I thought it was their equally rare 19" set. It's the same chassis! And, that was also a bear!
Yep. Nice, and cheap. Nice, and cheap. Great job bringing this monster back to life. How does the picture look with it's original CRT?

Did you also put new electrolytics in? You were truly lucky to find this set. I wanted it, but, just couldn't go pick it up. At least it's been saved. Great job...
Bill Cahill

Thanks Bill,

I have not installed the 24 inch crt yet. When I do I will post photos of the finished project.

I have not restuffed the cans yet. I will be doing that shortly, when the new electrolytics arrive. I also wanted to see if the other major components were functional before expending the effort. No sense in puting a lot of work into a chassis if some unobtanium component is defective.

I wouldn't worry too much about the crt. Even ones I've seen that are at the '?' work good enough. It seems to be when that needle only moved 1/4" or so that you really have a problem.

One thing about a Muntz chassis like that...there really isn't much that can go wrong!

You can bet he got a good deal on the trannies from somewhere! ;)

Wow! I thought my electrostatic Motorola 9VT1 was a simple chassis. I see there are very few setup controls also. I would expect this set to have imperfect linearity, retrace lines, yoke ringing and other performace anomalies associated with inexpensive sets. The only bragging feature is that it has a 24" screen. Any idea what that set sold for new? Please post a picture of it set up with the original CRT. I'd love to see what one of these looks like when operating according to factory specs.

If Muntz was alive today he would probably make an LCD set where the entire chassis consists of one surface mount IC embedded into the back of the display.

I think there are more caps in a Motorola VT-71 than in the Muntz. I counted around 27 looking at the underside photo. Can't wait to see a shot of the 24" crt.
kevin

Hey Bob:

That set is looking good! I suspect that it will produce a pretty nice picture. That chassis is not all that bad. It still has three stages of IF which is more than some sets had. The really stipped down Muntz's came out a few years later. I think that big chassis helps to make it look so bare. I'm currently working on an unusual Motorola VK-101 and I'd much rather work on the Muntz!

Steve

Bob,

Great work on the Muntz! How much HV does the set produce? Looking forward to pictures of it operating.

Hi John,

According to my Pamona HV probe which has a 0 to 40KV scale, I am getting 16KV at the socket on my 5" test crt.

It will be at least 2 more weeks before I have the set completed. I have ordered caps to restuff the cans and will be going on vacation for a week before the caps get here. After the cans are restuffed, I will re-install the 24inch crt and post another photo of the BIG tube operating.

Bob

Hi Kevin,

Actually there were 23 caps if I countd the dead ones correctly. Stay tuned...photo of the big tube will be about 2 weeks from now.

bob

Hi Steve,

So when are we going to see a photo of that VK-101 Steve? Saw a photo of one in the net. Cool looking set. You sure have good luck in getting some cool sets.

I think the Muntz will probably get a pretty fair picture from what I see on my test crt. also need to do a little touch up work on the cabinet. It has a few scratches and is rather dirty. The chassis had a lot of soot on it from being in a dirty basement for many years. Need to take the safety glass off and clean that area real good too. Need to patch some tears on the speaker cone too. But most of the hard work is already done except for re-stuffing the cans.

Bob

Aw shucks guys, you make me want to restore my 1954 RCA Victor Model 21-T-373 instead of getting rid of it...

Nice job on the Muntz TV.

Sal Brisindi