Hello-

I bought this TV from a local ad because it looked interesting, and I have not found much information about it yet. It is a Muntz 721CV 21" color TV that seems to be from 1957, and the chassis may be the same as an RCA CTC-5.

http://70.36.238.5/muntz/IMG_0386small.jpg

http://70.36.238.5/muntz/IMG_0381small.jpg

http://70.36.238.5/muntz/IMG_0380small.jpg

http://70.36.238.5/muntz/IMG_0387small.jpg


It is interesting, the controls have labels that replaced the original functions, as if Muntz used an existing control panel but relabeled it to include the color controls.

http://70.36.238.5/muntz/IMG_0392small.jpg

The controls are relabeled as follows:

(Old) New
(Contrast) Brilliance (brightness)
(Brilliance) Color
(Vertical) Hue
(Horiz.) Contrast

even cabinet looks like a RCA

John Folsom has one in blond--the only other one known til now! I think his is missing the repurposed plastic panel. It's a Muntz cabinet with an RCA CTC-5 DeLuxe chassis.

Great score, especially if the 21AXP22 is good! I bet muntz did not make or sell many of these....

Tom C.

That appears to be a B&W control panel based on the old functions, what a way to save a buck!

It doesn't look like there are any controls there though?

you roll the controls with your finger from the bottom

Wow.... That's way Kewl !

I love it when these rare oddball roundies appear :) and this set looks really cool and of course very much like a CTC-5 as stated by those who have responded so far. Hope you get this TV working good and soon be posting pics of it in working order :).

Since Muntz was shunned "Back In The Day", there may not be many of these around. Great that a collector found it and it is appreciated for what it is. Hope you get it going...

Here is the blonde version, with missing knob escutcheon panel. This cabinet was very cheaply made, and the chassis is a stock RCA CTC-5.

John, your side control-panel area is different from this one. Here is a picture of the control panel, and of the controls in the panel below the screen:

http://70.36.238.5/muntz/IMG_0390small.jpg

http://70.36.238.5/muntz/IMG_0397small.jpg

John's TV appears to have an RCA tuner, the same as a regular CTC-5, while mine is different:

http://70.36.238.5/muntz/IMG_0389small.jpg

John's TV appears to have an RCA tuner, the same as a regular CTC-5, while mine is different:

http://99.92.93.245/muntz/IMG_0389small.jpg
Looks like a Standard Coil Neutrode tuner. It was the tuner found in most Muntz sets of that era. Also looks like the " cheapie" color circuit with the 12AT7's

I think it's great another MUNTZ is saved from the scrap heap. Actually a clever control design well thought out with hue, br. and color controls receeded? the faux speaker grill flips down for easy access to vert. horiz. The more obvious user controls easier accessible . IS that an Omega symbol broken off after Muntz badge? Chris does really nice work restoring tvs and I'm excited he found such a rare set to one day bring back to life. I think RCA customers would of been happier if less used color controls were set aside from day to day user controls. DOES this have a modified ctc5 chassis? It seemed ctc5 has more controls on chassis, moved to tuner?

:tears::yes::thmbsp:

rgb, tears only used as I wish found set

Until I saw the chassis photo, I'd forgotten about the HV cage with the tediously long captive screw on its cover that you had to wind in and out to access the 3A3 & 6BK4. An annoying concept.

John Fosom suggested his Muntz color set uses an RCA CTC-5 Deluxe chassis. The consumer controls are totally in a different configuration than any RCA CTC-5 model, being located below the screen in a pencil box. Chris' Muntz has them on the side with that strange tuner? Jon's Muntz also has the controls on the side with the channel selector in a different location. Could Chris' Muntz be a prototype and John's a production model? Or perhaps Chris' set has a replacment tuner? I'm confused.
Couldn't find a SAMS listed for this model.

-Steve D.

From what I've observed and learned servicing early color sets beginning in the late 1950s, RCA worked hard to encourage and pave the way for other television manufacturers to offer color TVs to the public. For example, 15GP22s and deflection yokes were supplied to the engineering departments at most if not all TV makers. I also know first hand that RCA "lent" engineers to Admiral when the latter was developing their 21" color sets.
I speculate that RCA sold Muntz a semi-assembled basic CTC-5 chassis less tuner(s) and control panels.
I wonder where the static & dynamic convergence controls, screen & background controls, all of which were behind the front pencil box on the RCA built CTC-5 models, were re-located to on the Muntz?

Here is a picture of what remains of the tube layout diagram on the back panel. It appears to be a Super/Special rather than a Deluxe CTC-5. I have not yet checked to see which type I have, but now I am curious enough to go look.

http://70.36.238.5/muntz/IMG_0385small.jpg

IS that an Omega symbol broken off after Muntz badge? Chris does really nice work restoring tvs and I'm excited he found such a rare set to one day bring back to life.
I think that may have said "Muntz Color" at one time, or maybe "Muntz Color TV" since their regular logo reads "Muntz TV".

Thank you for the compliment!

On my set, the controls behind the front fold down door are as indicated in the rCA CTC-5 deluxe service data. However, the wooden escutcheon panel has fratory holes in the panel and decals for the horiz. and vert. hold controls. But the tone, tint, color and contrast controls have crudely cut holes and hand scrawled glued on paper labels. Thee hole in the side of the cabinet for the tuner shaft is crudely cut. So I am not sure how to interpret all this data.

John, your tube diagram matches mine, and appears to be for a Super/Special chassis. The tuner diagram (VHF) appears to physically match the tube locations in my tuner, and their numbers do not match those in an RCA CTC-5 tuner (KRK-35). Very interesting.

I confirmed-my chassis is a Super/Special. It has two 12AT7 tubes and five tubes total on the color board. I also noticed that the 3.58 MHz crystal is in a tube-style case-is that typical on a CTC-5?

http://70.36.238.5/muntz/IMG_0408small.jpg


I removed the cover over the chassis front controls and took the pictures below.

http://70.36.238.5/muntz/IMG_0402small.jpg

http://70.36.238.5/muntz/IMG_0403small.jpg

Very interesting sets-it's the little idiosyncrasies that I really like about these. I suspect this had to have been about the cheapest way to buy a color set in '57.

My CTC-9 had a glass envelope 3.58 crystal like that, though it was soldered in under the chassis.

My CTC-7 has the glass-envelope crystal under the chassis, too. Had to scratch my head for minute, until I figured out what it must be.

I love how those new legends (COLOR, etc.) look like they were just rubber-stamped over the originals. Be careful when cleaning -- you don't want to rub them off!

Phil Nelson

So the Muntz color set turns out to be the cheapie version of a 5 after all. I'm shocked, shocked I tell you. :arrow:

My CTC-9 had a glass envelope 3.58 crystal like that, though it was soldered in under the chassis.

Likewise my CTC-10 has the glass envelop.

OK, so the glass-encased crystal is not unusual, thank you all for the notes. I don't remember noticing what my CTC-5 has, and it is on loan to a museum right now.

I would have expected my CTC-7 to have one as well, but is has a metal case crystal with really long leads. It seems there's no rhyme or reason to what crystal made it into one chassis or another. 'Course, the one in my '7 could be a replacement...

that cabinet even looks a little like the ctc5 special, the lowest end of the ctc5's Anyway its a ctc5 chassis with a twist!

After viewing the various photos of both sets, each having a tube chart that is similar to the CTC-5 Special/Super chassis. Except for the tuner. I suspect Chris has the original Muntz chassis in his set. I see in Chris' post #22 the photo of the chassis front panel that has the convergence & screen controls ect. also shows the empty holes that RCA used for their user controls, which Muntz has grouped with the tuner. John's set may have had a Deluxe chassis installed to replace the Special/ Super chassis at one point. John's tuner also from a CTC-5 Deluxe side mounted model. Hence, the holes cut in the cabinet side for the channel selector. John's user controls are also under the screen and have the 6 controls as on the CTC-5 Deluxe chassis. Which would explain the holes drilled in the wood panel between the hortz. and vert. controls and the crude handwritten legends. There are other differences on both sets that would require a SAMS, if they had one, to futher verify what's original and what's not.

-Steve D.

Here is the bad news: The 21AXP22A CRT has open filaments. :tears:

The CRT appears to be the original, made in the 13th week of 1957 based on the label on the CRT connector. Well, I will at some point go looking for a usable CRT for this set. It is a gray-face type (as may be all AXP's?), but I remember seeing a discussion that some newer ones (early FBP's?) were also gray. I know conversions were done with glass CRTs, but I would not do that on this set unless it was a completely reversible (and ideally, invisible) process. Have any of you done such a task?

Chris,

My CTC-5 has been converted to a 21FB tube. This was done before I bought the set many years ago. The conversion kit supplied by RCA replaces the insulating boot and most 21AX mounting hardware with a metal disc that surrounds the 21FB bell and has latches welded to it with struts that extend to the existing mounting hardware behind the mask. I have never seen these RCA conversion kits available on e-bay or anywhere else. Certainly finding a good 21AX would be the best solution.

Best,
-Steve D.

Chris,

My CTC-5 has been converted to a 21FB tube. .

Would you have a picture of this mount as I need to do similar (install all glass roundie)
for my Whitby Deluxe. I know it won't be easy.

New Vista,

sending you an e-mail via VK.

-Steve D.

Here is the bad news: The 21AXP22A CRT has open filaments. :tears:

The CRT appears to be the original, made in the 13th week of 1957 based on the label on the CRT connector. Well, I will at some point go looking for a usable CRT for this set. It is a gray-face type (as may be all AXP's?), but I remember seeing a discussion that some newer ones (early FBP's?) were also gray. I know conversions were done with glass CRTs, but I would not do that on this set unless it was a completely reversible (and ideally, invisible) process. Have any of you done such a task?

You can do a reversible glass CRT replacement by removing and saving all the metal tube hardware and jury-rigging whatever is needed to mount the glass tube, screwing it to the existing bezel. From the front, it fits perfectly.

I'm not sure and a basing diagram was useless in confirming or denying how the filaments of the three guns are internally connected in a 21AXP22 and later roundies. My memory says that they are in parallel, not series. If that's true therefore, it's very improbable that the filaments in all three guns are open.
Hence, if all three filaments are dark, that would seem to indicate that the two solder connection on the base pins need to be re-soldered.
The tube might not be beyond hope.

Hence, if all three filaments are dark, that would seem to indicate that the two solder connection on the base pins need to be re-soldered.
The tube might not be beyond hope.

Or more probable for a 21AXP, the tube has gone to air and they burned up. :sigh:

It just crossed my feeble mind that this 21AXP22 could also have gone to air, frying the filaments. However, it would certainly pay to be sure. I guess Eric and I wrote our posts at nearly the same time.

here are photos of how I used a CTC-7 mounting ring and some hardware store parts:

http://www.flickr.com/photos/42002845@N02/sets/72157627018247265/

here are photos of how I used a CTC-7 mounting ring and some hardware store parts

Got the job done neatly! Gives me some ideas.

It just crossed my feeble mind that this 21AXP22 could also have gone to air, frying the filaments. However, it would certainly pay to be sure. I guess Eric and I wrote our posts at nearly the same time.
This is my main fear, yes. I will have to remove the neck accessories and clean the neck to see the getters as the next step. The CRT base is tight, and I was pretty sure I could see the wires at the end of each pin, so I doubt it is something nice and repairable like a loose wire.

here are photos of how I used a CTC-7 mounting ring and some hardware store parts:

http://www.flickr.com/photos/42002845@N02/sets/72157627018247265/
That is a nice mount for the CRT. Did you use the CTC-5's original yoke, and if so, how did you anchor it since it normally is held by the plastic shroud? I once worked on an early color set that had had its 'AXP replaced by a 21FBP22, and the (original) yoke was basically loose on the neck. I made a bracket that was suspended from under the top of the cabinet to hold it in place and allowed its position to be adjusted.

The RCA conversion kit supplied a later style back yoke cover to go on the CTC-5's yoke. It seems that I remember that it was a bit ill-fitting or a little hokey in some way, but it did the job.

That is a nice mount for the CRT. Did you use the CTC-5's original yoke, and if so, how did you anchor it since it normally is held by the plastic shroud? I once worked on an early color set that had had its 'AXP replaced by a 21FBP22, and the (original) yoke was basically loose on the neck. I made a bracket that was suspended from under the top of the cabinet to hold it in place and allowed its position to be adjusted.

The yoke is loose on the neck - I will take it off in case of any big moves, to avoid possibility of breaking the tube. But convergence/centering/purity wise it's working fine. I can't remember now if the internal plastic sleeve has some expanders stuffed in it (probably at the top) to keep it from tilting backwards, and I can't see past the convergence coils to see what's there at the moment. I do know it slides pretty easily.