The beast arrived, courtesy of "aerials."

Tim and aerials did most of the grunting
http://farm7.static.flickr.com/6162/6178750398_1d6d9b1586_z.jpg (http://www.flickr.com/photos/42002845@N02/6178750398/)
P9240005 (http://www.flickr.com/photos/42002845@N02/6178750398/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

The tube has a cataract, but the filaments are open, so I don't have to fix the cataract :thumbsdn::thmbsp::pity:
http://farm7.static.flickr.com/6174/6178228023_132e8b1e8b_z.jpg (http://www.flickr.com/photos/42002845@N02/6178228023/)
P9240009 (http://www.flickr.com/photos/42002845@N02/6178228023/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

Fortunately I have an excellent tube in the console I got from miniman, along with a reasonable backup.
http://farm7.static.flickr.com/6153/6178748502_b3cd7af3fe_m.jpg (http://www.flickr.com/photos/42002845@N02/6178748502/)
P9240002 (http://www.flickr.com/photos/42002845@N02/6178748502/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickrhttp://farm7.static.flickr.com/6153/6178223111_965f13808a_m.jpg (http://www.flickr.com/photos/42002845@N02/6178223111/)
P9240001 (http://www.flickr.com/photos/42002845@N02/6178223111/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

Both of these are separate glass type, with the gasket that turns to ooze after all these years, so cleaning and retaping is all that's needed, as I understand it.

By now you should know that I go at these things slowly, so expect occasional progress reports.

now I have to look for some service info - and I have to back up and figure out the model numbers and chassis.

The coffin is Model 7500-3 (?) and the rest of the printing is smeared, but it looks like chassis 11L8T25Z (??)

The smaller console doesn't seem to have a visible model number and I haven't determined a chassis number either.

Is the chassis number stamped on the chassis somewhere?

Wayne:

The TV chassis should be something like 24MC23 or 25LC something. I believe that the 11L8... number is the radio or amplifier chassis. Unfortunately my Zenith service info for that set is in Wisconsin.

Steve

The number for the set you got from me is located near the HV cage, should be 25MC33 just like the other.

The number for the set you got from me is located near the HV cage, should be 25MC33 just like the other.

hmm - do you have to pull the chasis to see it?

Also, the chassis are not identical - the coffin has the power transormer at an angle and has what looks like a compactron in the section down under the CRT.

By the other, I was speaking about the one I got at that same estate sale. There were 2 sets and a spare chasiss, all the same. I can't speculate on what your huge combo has in it, pictures usually help and Mark would know best of all just by seeing it.

Does this one have UHF tuning? Sounds like the chassis sticker is missing, they are always on the HV cage facing the back of the set and they are pretty big so you can't miss them if they are still present.

Pictures of the combo:
http://farm7.static.flickr.com/6166/6187612854_66d75129bc_z.jpg (http://www.flickr.com/photos/42002845@N02/6187612854/)
P9260012 z combo (http://www.flickr.com/photos/42002845@N02/6187612854/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

http://farm7.static.flickr.com/6156/6187613522_166263e779_z.jpg (http://www.flickr.com/photos/42002845@N02/6187613522/)
P9260013 z combo (http://www.flickr.com/photos/42002845@N02/6187613522/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

http://farm7.static.flickr.com/6163/6187092909_da439595ee_z.jpg (http://www.flickr.com/photos/42002845@N02/6187092909/)
P9260014 z combo (http://www.flickr.com/photos/42002845@N02/6187092909/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

http://farm7.static.flickr.com/6170/6187614864_d744cf3f26_z.jpg (http://www.flickr.com/photos/42002845@N02/6187614864/)
P9260015 z combo (http://www.flickr.com/photos/42002845@N02/6187614864/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

pictures of the console for comparison:
http://farm7.static.flickr.com/6161/6187615444_4da3de0a30_z.jpg (http://www.flickr.com/photos/42002845@N02/6187615444/)
P9260016 z console (http://www.flickr.com/photos/42002845@N02/6187615444/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

http://farm7.static.flickr.com/6178/6187616044_612f4a2fea_z.jpg (http://www.flickr.com/photos/42002845@N02/6187616044/)
P9260018 z console (http://www.flickr.com/photos/42002845@N02/6187616044/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

you know years ago I read an article about picture tubes with open filaments. I know some of you are going to poo poo the idea, and you know what you can do, but in I believe it was popular electronics, or radio electronics back in the late 70's when I was rich enough to get magazines. I remember a project for attempting to repair picture tubes with open filaments. If you had a tube with this condition and it was known to be good and worth it, what you would do was hook up yer VOM to the filaments and wack the neck of the tube, and if the needle moved, then it was thought that the filament wire was close to touching, and could possibly be "welded" back together. Now this only worked on B&W or other series filament color tubes. The project included testing the tube for the needle movement, and then if it were moving, the filament pins were then replaced with a charged capacitor, and then the tube was to be wacked again in a way known to always cause the meter needle to move when it was attached. The key was to get a pattern identified where the meter needle was guaranteed to move, that way you knew you could reproduce it and get a weld when the cap discharged when it was across the filament pins. Since I don't have the magazine, you would have to do some thinking, experimenting, praying, or other magic to figure out what cap and voltage charge might produce a good weld, and not burn off the wires inside the tube and make a second attempt pointless. Anyway since the person in this post has an otherwise useless tube, I thought this might be worth a try. Since I am older now, and many of you are smart enough to know about harmonics, here are some additional things to try to make this successful. If you can't get the meter to move with a simple whack, you may want to try adding harmonics to the parts inside the tube to ensure movement. Use a speaker and audio generator, mount the speaker to the tube, and have the sound vibrate the stuff in the tube. Put yer beeper, or cell phone on vibrate and let it vibrate against the tube. etc, etc on any things that can set up harmonics inside the tube's elements. it might also be a cool idea to try and see if you can see the open spot inside the tube before you begin... you know use a flashlight, magnifying glass, clean the neck see what might be available to see. Who knows you might even have to warm up the tube in the sun, whack it to see if you get a momentary continuity, maybe cool it, whatever might be needed to try and get a possible connection. And I'll tell you one more thing I did as a kid. We has clear light bulbs, and on a few occasions when I was less than 20 and with lots of time to learn and do weird stuff, a few times I took those bulbs when they went bad and could see the broken spot, shook the bulb moved it around and got the wire to slide out of the little round filament holders till I got the filament flappin in the unbreeze, and got it to lay across what was left of the other end of the filament still attached to the other post, and wa-la I had a bulb working again.... I carefully screwed them into a socket where I typically got another month or two out of them. Since they were brighter, I assume if I dimmed them a little I bet they would have lasted longer... Not really a concern welding a picture tube filament.

I've never been bored or desperate enough to think of trying to wiggle the filament out of the loop, but have on occasion wiggled the filament in the clear decorative bulbs in the bathroom to get a weld and a little more life out of the bulbs when enough are burntout to make the place dim and spooky.

BTW what is that box above the HV cage only present in the combo?

I've tried the light bulb trick with some success, myself, and have attempted the charged capacitor trick. While it didn't work in my case, I think under the right conditions it could do well.

The crt in my CTC-15 had one open filament. I tapped lightly on the neck with a screwdriver while it was connected to the tester and the dead gun came to life. I may have had to do it once more, shortly after. Knock wood, no more trouble.

The box above the HV cage is the remote chassis.

Consider this: what are the chances that all three internal-to-the-tube filaments opened simultaneously? I would reckon the chances are pretty small. That is to say I have never come across an instance where the three filaments open simultaneously unless the tube is down to air.

Typically, I would expect a single filament to open at the weld or in the middle. Because the filaments are parallel connected in the tube, a single open filament would mean the other two filaments remain lighted and the picture would shift in hue. Unless the viewer is color blind, the picture would be unwatchable.

I would venture to guess that if the tube filaments test open, the problem could be the solder connection to the pin at the socket.

Wayne: Have you tried running a soldering iron on the filament pins and run a bit of fresh solder?

Incidently that set is a nice find. That was a great chassis and was my first color TV nearly 40 years ago.

Terry

In the event of missing chassis number stickers, you can always use the tube location diagram found on the inside of the cabinet as those will also indicate the chassis number. Im guessing your combo to be something around a 25LC20Q

Thanks for all the hints - had no time tonight, but will get back at it tomorrow.

Is the combo the one you are calling the coffin?

Ya mind if I ask where you dug it up?

"The box above the HV cage is the remote chassis"
Remote chassis for what?
Phil

Take a wild guess, there's a radio and a TV in it...

Never seen a Space Command chassis in a black cage before and got confused.

I'm smart enough to know what it controls.

Is the combo the one you are calling the coffin?

Ya mind if I ask where you dug it up?

Yes, long combo is often called a coffin model.

Aerials, who has been much more than kind and generous, found it and eventually gave it to me based on the expectation that I will restore it, as I did the family CTC-5 that he gave me a few years ago.

In the event of missing chassis number stickers, you can always use the tube location diagram found on the inside of the cabinet as those will also indicate the chassis number. Im guessing your combo to be something around a 25LC20Q

d'oh (slaps forehead) -- I did the imitation of a pretzel required to focus my bifocals on the inside of the cabinet, and found the info last night (will post when I get home tonight). I'm going to try snapping a pic of the labels so I don't have to do the human origami trick again.

I think one chassis was a K and the other a L, will post the full numbers.

Here's the coffin diagram, 25LC30. The console is 25KC20U.
http://farm7.static.flickr.com/6135/6193710214_f478f750ac_b.jpg (http://www.flickr.com/photos/42002845@N02/6193710214/)
coffin tube diag P9280023cr (http://www.flickr.com/photos/42002845@N02/6193710214/) by old_tv_nut (http://www.flickr.com/people/42002845@N02/), on Flickr

took the back off the stereo side - it is "11L8T25Z chassis", stamped in ink

I am thinking 1962 or 1963? Im sure Wayne you will get facts on this monster set. I am still trying to get that ctc-5 up in Auburn, In. I will try to drive up this weekend and beg as best I can. he has vintage B/W sets from the 1950's I have no desire for. You Guy's spoiled me with Color round tube sets. I look everyday to find and rescue another roundie. I thank everyone of you talented technicians to breathing life into historical sets.

Even though your set has chassis 25LC30 it sure looks different from mine. Check out the differences with the convergence assy and the power transformer! What date codes do you see? Mine is a very early 64 before the UHF mandate and no space command.

Even though your set has chassis 25LC30 it sure looks different from mine. Check out the differences with the convergence assy and the power transformer! What date codes do you see? Mine is a very early 64 before the UHF mandate and no space command.

I've seen the finned power transformers before, never paid attention to what sets they were in. Regarding the convergence coils, is it possible yours were replaced at some time? (I'm guessing mine weren't, since there seems to be the same layer of dust on the tube neck as on everything.)

I've seen the finned power transformers before, never paid attention to what sets they were in. Regarding the convergence coils, is it possible yours were replaced at some time? (I'm guessing mine weren't, since there seems to be the same layer of dust on the tube neck as on everything.)

The 25LC30 is covered in sams 722-4 and my convergence assy looks like the one they show on the rear view pix. Variations are always possible....

Silly me. When I saw "remote chassis" my mind switched to "remote (tuner) chassis", but I knew that wasn't right. About as bad as when I read "General Cement" and my mind switched to "General Concrete". Miniman82, I'd really rather have a Wild Turkey right now than a wild guess.

WOrks for me, take a shot and down some A&W. Sounds odd, but the caramel aftertaste mixed with the Turnkey is glorious.

Mine is a very early 64 before the UHF mandate and no space command.

Put a DTV converter box or cable box on that set and you won't need Space Command, as these boxes come with their own remotes that will operate the set's basic functions -- including on-off in most cases (see my note below). The Zenith DTT-900 and DT-901 are two very good DTV converters from what I've read here (never had any experience with one because my flat-panel set already has an ATSC tuner and remote, though I am presently using a GE universal remote with the TV, my VCR and DVD). Unfortunately, however, the on-off button on the DTT-900/901 boxes won't work if your TV doesn't have remote control, but the other basic functions (channel +/-, volume +/- and probably mute) should work just fine. VK member Electroking in Montreal has one of these boxes on one of his older TVs without remote; the power button on the DTT-900/901 remote won't work on that set either. In these cases, you must switch the TV on and off manually, or else get a switch on a long cord that plugs in between the AC outlet and the TV. I don't know if this type of "wired remote" is still available (I had one back in the '70s), but if you can find one, it will more than compensate for the lack of on/off switching at the converter box remote, although you will need to be wary of the cord. Zenith's first TV remote control system, the "Lazy Bones", was introduced in 1950 and had the control unit on the end of a very long cord; that cord was unsightly and also created a tripping hazard, as it often ran across the room in which the television was located. The Lazy Bones system was replaced with the Flash-Matic remote, Zenith's first wireless TV remote control, in 1955; the Flash-Matic, after only one year (!) and many customer complaints, was replaced by the Space Command ultrasonic remote system . . . and the rest, as they say, is history.

I've got a newer "wired remote" for 120VAC outlets that was bought for use with christmas lights a few years back (the thing is green).

RE: Welding open filaments. I did that years ago back in the 80’s. I have had a few junkers with open filaments that whacking the tube would make it work for a while. I charged a 10mfd cap to 250 volts (no math here I had a 250 vdc regulated power supply and a 10mfd pigtail cap). Wired it up and whacked it! The tubes lasted for years after that. I do recall some color tube filaments being wired in series. I don’t remember what types…

Getting back on track (finally) - I started to look at the set after a long time of ignoring it, and I find none of the tubes are listed on my old Realistic tube tester.

Anyway, my planned order of business:
Test all tubes and order replacements if needed
Pull TV chassis on both sets (coffin and CRT donor console) and stereo chassis on coffin
Pull dead CRT and get rid of it
Pull donor CRT, remove glass and clean/replace gasket
Install donor CRT
Cap census - purchase caps
Recap coffin TV and stereo chassis

Estimated time of completion August??

Besides finding a tube tester, I think I need someone to help put the coffin on its face for CRT replacement.

:banana:Yes, the tube chart in a Zenith would definitely have the chassis model.

That will be a really nice set when you get it going. I just wonder what killed the filament? I've rarely seen dead CRT filaments.

Well, I started to look at this set again, and immediately got stuck. The manuals have nice diagrams of what on the control panel connects where on the chassis, but no instructions on what to disconnect or unscrew from the cabinet to remove the chassis - that is, what has to go with the chassis and what stays in the cabinet, and what do you remove first. Some things have obvious plugs, but others, like the color controls, SEEM to be hardwired to the chassis. So now what?

My planned first step was to pull the chassis so I can swap CRTs and also begin work on caps, but I'm still scratching my head.

Anybody know how this set is supposed to come apart? Am I thinking of it backwards and the bezel should come off somehow first?

look in the compartment up front where the controls are. There SHOULD be 2 phillips screws. Remove the knobs, remove those two screws. The box unhooks in back from the bezel! The power/volume knob is (2) 1/4 inch screws. The speaker unplugs from the chassis. as does the convergence and tuner. Watch the HV suction cup! :) Unplug the yoke wires, and the chassis should ease out.

If it's like my 25LC20, the controls box can be hooked onto the front of the chassis and secured with a screw to hold it in there so it doesn't flop around.

Just look it over carefully, and it's pretty obvious once you do it the first time.

look in the compartment up front where the controls are. There SHOULD be 2 phillips screws. Remove the knobs, remove those two screws. The box unhooks in back from the bezel! The power/volume knob is (2) 1/4 inch screws. The speaker unplugs from the chassis. as does the convergence and tuner. Watch the HV suction cup! :) Unplug the yoke wires, and the chassis should ease out.

If it's like my 25LC20, the controls box can be hooked onto the front of the chassis and secured with a screw to hold it in there so it doesn't flop around.

Just look it over carefully, and it's pretty obvious once you do it the first time.
It must be 30 years ago, since I pulled the chassis from one of those. I'd probably remember the proceedure. :yes:
BTW, looking over the entries on this thread, we haven't heard from Electronic Memory in a long time. He must be taking his College education seriously.
For a young man, he seemed to be well versed. :thmbsp:

Glad you are working on the coffin again.

I am still curious about the tube and how all three filaments would simultaneously open. Perhaps a bad internal weld? My thought was perhaps a bad solder joint at the socket. Did you further investigate this?

I assume you must have ascertained the tube to be bad?

Glad you are working on the coffin again.

I am still curious about the tube and how all three filaments would simultaneously open. Perhaps a bad internal weld? My thought was perhaps a bad solder joint at the socket. Did you further investigate this?

I assume you must have ascertained the tube to be bad?

I remember your question about the filaments and will retest to see if I can find out what's what.

I tried resoldering the filament pins, and they still test open. At some point (probably after swapping in the known good tube) I may completely remove the socket and test directly to the wires. For now, it's just no go. The socket is a bit loose, and I tried wiggling it, but no success.

Both this 21FJ and the replacement 21FB are marked Zenith, but have RCA EIA codes (274)

I got back to trying to clean the donor faceplate, and nothing seemed to work - there was always a residue, until:

I got some nail polish remover (acetone) and that seemed to be loosening the hazy stuff and moving it around (but still leaving something). So then I tried full concentration dish soap, and voila! It removed everything this time, I guess because the acetone left stuff that was now removable.

Since the donor faceplate rubber gasket seems in decent shape, I intend to use it.

I am wondering if (with the set on its face) I can drop the faceplate in first, then set the regunned tube in on it, rather than trying to fasten the faceplate to the tube first?

I also have all the restored chassis back (TV, radio, audio amp, remote), along with the turntable, which I am told is working only in manual mode as of now, and needs a new stylus. (It's a long saga, the guy who was working on everything got a full-time job, also had some health problems, and scaled back time on this.)

Now waiting to make contact with the person who is supposed to help with the CRT install and re-assembly. It's just too heavy for me to be flipping over by myself.

Doug Harland, a great guy, came over today and spent 8 hours putting all the chassis back in place and connecting everything while I acted as gofer. I'm so glad he did, because this set seems to never have used identical screws for nearly identical functions. I would have spent a week just trying to figure out which screw held what to the cabinet.

First thing, though, was to replace the picture tube with the rebuilt from Scotty and a faceplate from a donor tube. I thought the original faceplate gasket would be Ok, but it had continued oozing gunk and had to be discarded. So, there was a detour to Home Depot to look for some gasket material. We bought several kinds. Here is the stuff that worked out best:

https://farm6.staticflickr.com/5725/20836774031_951dc8258e_z.jpg (https://flic.kr/p/xKgUYF)CAM01072 (https://flic.kr/p/xKgUYF) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

https://farm6.staticflickr.com/5820/20836773001_eff81172c0_z.jpg (https://flic.kr/p/xKgUEV)CAM01073 (https://flic.kr/p/xKgUEV) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

You stick the gasket to the tube, then lay on the faceplate, and finally seal it against dust with clear packing tape.

https://farm1.staticflickr.com/755/20820169762_5f8134538b_z.jpg (https://flic.kr/p/xHNP7b)CAM01068 (https://flic.kr/p/xHNP7b) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

https://farm1.staticflickr.com/773/20803381686_3491266e9e_z.jpg (https://flic.kr/p/xGjLAA)CAM01077 (https://flic.kr/p/xGjLAA) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

In this set, the CRT mounts from the rear. It mounts to a plate behind the bezel, and the plate and CRT have to be removed and dropped in as a unit. The bezel itself is cast zinc.

https://farm1.staticflickr.com/617/20803391086_87c8c4eb02_z.jpg (https://flic.kr/p/xGjPoE)CAM01082 (https://flic.kr/p/xGjPoE) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

https://farm1.staticflickr.com/637/20207076164_3bb417d55f_z.jpg (https://flic.kr/p/wMCxJU)CAM01084 (https://flic.kr/p/wMCxJU) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

https://farm6.staticflickr.com/5789/20207085454_c98984204b_z.jpg (https://flic.kr/p/wMCAv5)CAM01090 (https://flic.kr/p/wMCAv5) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

https://farm6.staticflickr.com/5740/20820203662_3325cf602c_z.jpg (https://flic.kr/p/xHNZbE)CAM01093 (https://flic.kr/p/xHNZbE) by Wayne Bretl (https://www.flickr.com/photos/42002845@N02/), on Flickr

Did I mention Doug is a great guy? He stayed 8 hours until everything was connected and could be fired up. Unfortunately, the result was not simple plug and play - some tube sockets appear intermittent; and Doug also suggested testing tubes with a better tube tester to weed out any with grid emission.

The audio amp and tuner do work, if the source switch does.

Currently needing debugging:
Audio selector push buttons switch in the stereo did not want to turn off when "off" was pushed. This is a problem because it also kills the TV sound.Finally got it to turn off after a dozen tries, but probably ready to fail any moment.
Remote control is balky - probably needs retuning, and looks like some old caps are present and may be a problem.
Cannot make cutoff - extinguishing the lines in setup mode leaves a medium bright raster even at minimum brightness setting.
No RF snow; can get audio noise intermittently by playing with tube seating.Tried Deoxit on IF tube sockets, which helped a bit, but still intermittent.
Phono works in manual mode, but won't complete automatic cycle (probably loose belt).
Convergence cloverleaf is broken in two places, currently held together with electrical tape and a tie-wrap. Need to find a replacement if possible.

So, will be investigating tubes and sockets and looking for what's wrong with cutoff.

To thank Doug, I gave him the old CRT (with the hope that the open filaments are a lead wire issue and not actually open) and an interesting Zenith portable (OOF! you call this portable?) from 1980 with continuous VHF and UHF tuners.

Question about moving a set like this:

Do you think regular home movers are suitable (worry about necking it!) or should special movers/shippers be used?