As you all know I'm restoring my 1965 25MC33 Zenith TV. I thought I'd chronicle the restoration progress here for those interested. As of today, 18-May-2007 the set is in a state of disassembly. Scotty at Hawkeye called me to tell me that he is almost finished rebuilding my picture tube and that the process is going well. I should have the tube back sometime next week.

The cabinet is still at the refinisher's so no progress there yet.

I have repaired the broken tube cap since I could not find a replacement. I found an adhesive that is like J.B. Weld for plastic and fixed the cracks. I am going to repaint the tube cap so the repairs are not so obvious.

I have cleaned the bezels for the CRT and control panel. The paint is somewhat worn but I am just going to leave it as is. I fixed the magnetic closure on the control door so it no longer flops open.

I have got most of the vintage crud off of the chassis and cleaned the front panel controls. I have replaced all the power tubes in the horizontal and HV section. I still have to clean both tuners, the yoke, the convergence panel and the automatic degauser. I still have some capacitors to replace in the power supply. I have to replace the flat lead wires from the antenna connections as well as many other little things. I have to repair a small crack in the volume knob. This set appears to have suffered from years of neglect.

I'll post some pics as she comes together.

wow , thats a lot of time and money into that set . Hope you keep it . After all that work it should be around another 40 years .

I definitely plan to keep it. I do not have room to "collect" roundies so this is my one and only of this particular species. It is much easier to find places to use and store my collection of Bakelite tube radios than to accommodate a herd of console TVs. I have always wanted one of these sets so to me it is worth the effort. I just hope the end result is all I expect it to be.

Here is a "before" picture

Scotty at Hawkeye has finished my tube and has shipped it out. It will be at least two more weeks for the cabinet as the refinisher is busy. In the meantime I have been cleaning the yoke, legs, back cover, etc. When the cabinet is done, I want to have the rest of the set ready for assembly. Since I have to clean all the controls it will take a while to get all the adjustments back to where they should be. Fortunately I have the Sams so I have all the procedures for setup and adjustment. I really think this set is going to turn out well.

Yesterday was a busy day for the old Zenith. I disassembled, cleaned and reassembled both the VHF and UHF tuners. One really has to admire the way these tuners were built. I cleaned all the contacts, removed the turret and lubricated the moving parts. Everything went together well with no pieces left over:yes:

I had to reglue the convergence magnet assemblies as they were starting to come apart. The chassis is cleaned up, all controls sprayed with Deoxit and the tubes polished with Windex. This set must have been in a smoker's home because there was brown crud on practically everything.

Although I can't hook up the CRT and test it thoroughly because the cabinet is still not ready, I was able to hook up the tuners and speaker. The signal path seems to work (at least the audio portion) as I have sound reception on all channels. The vertical oscillator is running and its pitch varies with the vertical hold control. The high voltage section is operating and I was able to get almost 30 KV out of it. I did not run the HV for too long as I just had the probe hooked up. I know I need to adjust the efficiency coil. When the set is back together I will go through all the setup procedures in the Sams.

When I first powered it up I saw a little smoke rising from an opening in the chassis. There was no component burning smell, however, just the smell of tubes and burning dust. I think that is all it was since it has stopped and careful observation reveals nothing out of order. I can't check the video and color circuits as I don't have a scope. I'll just have to wait for the cabinet and really test it when I can install the tube.

The sound on this set is amazing. Even with just the small oval speaker, the set has more volume and richer tone than our 27" HDTV with stereo and BBE, etc.

I will post another update when I get the cabinet back.

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Are you sure you want to leave that black beauty I see on top of the chassis?

Thanks, I'll check into that. The black box you see in the photo below is a combination VCR, DVD Recorder and Digital ATSC Tuner unit. I hooked it up to my 8" RCA portable and it works great. When I had the RCA hooked up to an old VCR there were retrace lines on some channels. This unit gives no retrace on any channel or the DVD. Here is a screen shot of an Outer Limits DVD. This is the unit that is going to supply signal to my roundie.

The stereo receiver below is a 1974 Pioneer SX-626 for the audio enthusiasts among us.

I got the cabinet back and assembled the set. It works!:banana:

I do have a question regarding setup. I completed all the procedures and got it looking great. Later I moved the set to where it will reside so I could give it a good run-in before I put the back and bottom covers on. In the new location, I noticed the purity was off. I corrected it only to have the convergence settings change. I have never seen a set so location sensitive. Modern sets, especially portables don't have this problem. Can anyone tell me what it is about these early sets that makes them this way? Or what is it about newer sets that makes them more immune to location changes?

So far, I'm quite pleased with this set. It has turned out well. I suspect I still need a couple of tubes because when it is first turned on, the picture flashes and the brightness changes. Tapping the video output tube seems to aggravate the condition. Once it has been on for a while, it is steady. Occasionally the vertical will slightly shrink for a split second also.

Here are a few pictures. The cabinet restoration came out well. I added threaded inserts to the screw holes where the bottom plate attaches and where the front cross brace (not shown) attaches. It works great off the ATSC tuner as well as DVD except the copy protection put lines in the top of the picture. Any way to get rid of these?

I feel like I have finally joined the roundie club.

That's a nice looking set. It's always good to see more roundies working. I wonder how many working roundies there are now, it seems every couple of weeks another one of us gets one going. I would think that the number of working round color sets might actually be rising.

That's a nice looking set. It's always good to see more roundies working. I wonder how many working roundies there are now, it seems every couple of weeks another one of us gets one going. I would think that the number of working round color sets might actually be rising.

Thanks, I hope the number of working roundies is rising. These are really nice sets and so unique compared to today's black or silver look alike sets. Even though it displays a little less information, I stil prefer the round shape of the screen.

Great job Compucat. Considering the original condition, you brought it back right from "the brink". Hey, I see you found the correct VHF tuner knob! I don't recall hearing the story.

Where is the arc-shaped wooden brace that goes between the two front legs? It's in yout "before" shot. Don't leave it off, it's part of the charm (and maybe necessary for safety).

As I recall, the one we had from 1964 to 1976 would split-second shrink the vertical, every time the fridge kicked in.

There are filters that will remove the DVD lines. I have one that I built from a kit in 1986 or 87. Still works. Search this forum for macro or macrovision.

I haven't touched my '66 since driving to Cleveland to get it. It's working original, but probably needs a whole resto before trusting it. I couldn't be more envious of yours.

Excellent work!

Where is the arc-shaped wooden brace that goes between the two front legs? It's in yout "before" shot. Don't leave it off, it's part of the charm (and maybe necessary for safety).


I have the wooden cross brace, I just have not installed it yet. I'm not going to leave it off because I too believe it is part of the charm of this set. It is just a cosmetic piece however as it fastens to the cabinet with two screws in the center. I put brass threaded inserts into the screw holes where the brace fastens as one of the screws stripped out the wood and would not tighten. This way, if I want to convert it to table top use, I can remove the brace and reinstall it as needed without damaging the cabinet. The legs are the screw-in type so common on 1960s TVs. This set is going into daily service in my bedroom. With the ATSC tuner/dvd/vcr unit I can watch just about anything on it.

The round tube color Zenith has been the set I always wanted since I started messing with this stuff as a kid. My grandparents had one almost exactly like the one I have in 1974 and I fell in love with it. I only wish they had kept theirs but in the mid Seventies when it needed service, the TV repairman said they should just get rid of it.

The purity issue you ran into is not uncommon. Not sure if yours has automatic degaussing (I think that was about the time Zenith added it?) but without it you really need the set close to where it will sit when you do the setup. In particular it should be facing in the same direction-moving it front to back won't cause problems. I suspect all the metal in that set, and the relatively inprecise neck components, would make them more susceptible than later model sets. Some of the wildest purity issues I ever saw were on a late model tv installed on a ferryboat. At the dock they turned the set on and it looked great thanks to the autodegausser, but as the boat turned things went all kablooey.

Those sets don't have any kind of auto-degauss IIRC, so that's why they are so easily thrown off.

I transported my latest roundie home 100 miles in the back of a truck, purity was only slightly off when I put it in place. The degaussing coil made quick work of it though. On the other hand, a past Zenith roundie I owned had such bad purity that I junked it after I couldn't correct it.

This was back when I was young & dumb, and thought I was the only person in the world who liked old TVs. :no:

This set does have automatic degaussing. If I display a red raster and rotate the set, I can watch the purity change. I read elsewhere in this forum that round tubes are more sensitive to magnetic fields. Is this true? This is my first color roundie. I always thought convergence was a one-time setup procedure but someone posted that every time a roundie is moved to a new location, purity and convergence may need to be redone. Is this just a characteristic of early color tv? If it is, I don't have a problem with it. I'll redo the setup in its final location and I expect everything will be fine with it. As long as I don't move it, the picture stays great.

If these sets have to be setup whenever they are moved, I expect most people did not have them adjusted whenever they moved the set to another room or another house, etc. After the initial setup by the service technician, these sets probably never looked their best again. No wonder some people remember these as having a lousy picture.

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If these sets have to be setup whenever they are moved, I expect most people did not have them adjusted whenever they moved the set to another room or another house, etc. After the initial setup by the service technician, these sets probably never looked their best again. No wonder some people remember these as having a lousy picture.

Exactly. They are extremely sensitive to magnetic fields, including the one of the earth. If a roundie is going to look it's best, it should be degaussed and set up in the position it is going to sit.

Automatic degaussing is a good first step toward a "permanent setup", but II would bet the convergence will also change slightly if the orientation of the set to the magnetic field of the earth changes, even on a set with automatic degauss. I haven't tried anything like that lately. If you're curious, try it and see.

In any event, the the static convergence and purity magnets are pretty loose on most roundies. The adjustments probably move themselves if you haul the set. They always did when I moved my RCA.

Anothr reason they looked bad "back in the day" is that people either wouldn't or didn't adjust the front panel controls right. In general, you had to re-adjust if you changed channels, and sometimes even when the program changed. Most people turned the brightness up until it was blooming, and the chroma up until everybody's face was pumpkin orange, and left it that way. I had no idea roundies could produce an outstanding picture until I got my first one.

John

To get a really good picture on mine I had to go through the Sams and follow all the setup procedures, not just for convergence but for brightness range, CRT bias, AGC and so forth. It took quite a bit of tweaking but now I have good range on all the controls. The brightness will bloom a little and go out of focus if turned up too high but I have noticed this on all tube TVs. I have the front panel controls on very conservative settings and overall performance is excellent. I am especially careful not to have the brightness and contrast up too high as it is harder on the tube. I want this set to last a long time.

One thing I learned from the guys that worked on these sets in the day, at the shop they always set them up with the set facing north and south. They told me it was the only way to correctly adjust the CRT. I still do it this way today on our current monitors it does seem to help.

One thing I learned from the guys that worked on these sets in the day, at the shop they always set them up with the set facing north and south. They told me it was the only way to correctly adjust the CRT. I still do it this way today on our current monitors it does seem to help.

If you set it up with a North/South orientation will it adversely affect the picture if the install orientation is East/West? I went through the setup again last night in the set's final location in which the screen faces Northwest. The setup went well but I still have a little bit of impurity in one area of the screen. It is not too bad and I may just live with it since the convergence is really good now. It is not that noticeable during a color program. These sets really are sensitive with regard to their setup. I have noticed that the fleshtones on this set are great, very natural. This set has that warm color that I have always loved in Zeniths.

I have a 25MC30 (same basic set, mine in a cheap metal cabinet) and I could not get perfect purity in a couple spots no matter what. The trick that worked was stacking "refrigerator" magnets along the inside of the cabinet near the face of the crt. I ended up with about 6 stacked near the speaker and about 4 on the other side. A good place to get them is in the bottom of an old shower curtain, which has them sewn in so it will stick to a cast iron tub. Anyway, for me it worked. Later when I moved the set I was able to do away with some of the magnets.

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I changed the video output tube last night which seemed to eliminate the flashing in the picture. I touched up the AGC, buzz control and greyscale drive adjustments. The set is really looking good. I think I am at the point where I need to bolt the chassis down, install the back and bottom covers and declare victory. If I don't, I'll never stop messing with this thing. I get like this when I finish TV restorations. I keep checking and rechecking to make sure everything is right. After a while though, I relax and enjoy the results. I put on a DVD of classic commercials and it was like time travel watching 1960s and '70s commercials on a mid-Sixties TV.