I finally got sucked into another black hole. The house is already full of audio gear...100+ sets of speakers, receivers, amps etc. All vintage. I have read a few posts about the vintage TV's and came across one today that followed me home. I'm not sure how I did, you guys tell me.

It is a Zenith, chassis 20CC50 , Z. the pic tube has a tag that says AG23VBAP22. It is a color unit, for it's age in excellent cosmetic condition. The thrift store just picked it up today from what is probably the original owner. The lady moved to a nursing home and sold her home in an old part of town for over a half million $. My guess is it's been a daily user for many years. Picture seems good.

What can you guys tell me about this unit, what should I need to know. I plan to use a VCR to get the rest of the cable channels, should work right?

Pics to come once I get it in the house.

ken

Roundie or rectangular? Ahh, hell, it don't matter. You're hooked, or will be shortly. There's something about an old one-eyed monster from the Forties or early fifties..or a roundie... that says"I wanna come home w/you, mister...Please?" and you know you can't resist...-Sandy G.

The unit had one of those little cylinders attached with the cable end on one end and two spade termainals on the other. The UHF strips were attached to the VHF antenna. There is also a UHF tuner terminal. I've got the cable running into my VHS. What now??

I also have a high pitched squeal that is just audible enough to be annoying. It seems to come and go.

It looks like the side panels are plastic so I guess the unit isn't that old.

Here are some pics.

with the back off. Lots of tubes all appear to be Zenith brand.

Can't quite tell from that angle, but it could be the EXACT model I remember from my first years. May have been from 1972, from what family said.

The VCR is working hooked up the the UHF strips. I had to connect them directly to the coaxial cable, the little adaptor doesn't seem to work.

I did some searches and it seems to date to the late 60's , early 70's.

Seems to be a bit of distortion in the pic in the top inch of the screen

Like many of us first saw him??

The high pitch squeal seems to have gone away after a while

All the controls for VH, red , blue , green etc are on the back. I also found a thread that mentioned the 20CC50 chassis is hard to find. :yes:

:banana: switched the tape off and cable is now running through the VCR :banana:

The distortion at the top of the screen also goes away on the cable so it must be the VCR or it's interaction with the TV.

Nice set, Ken !! Now you need a GE "Locomotive", a bakelite Admiral, or a T-54 Hallicrafters to sit on top of it. A porthole Zenith would be nice, too-kinda a son/father thing.<grin>..-Sandy G.

A good set, glad you saved it. The cabinet might be half plastic but the chassis is solid, one of the last of the "real" tv chassis'. Many old sets have trouble with the output from a vcr. And the noise was a Zenith trait. Hmm... told you about all I know, enjoy!

Oh, I do know one other thing. The Sams photofact is #1238, dating this to 1972. Well, I'm a '72 model, too, so I'm partial when I say its a good tv!

If you would like a photocopy of the SAMS, send me a PM with your address. Ya never will never know if you will need it.

Nice Set!!

polaraman

The distortion at the top of the screen also goes away on the cable so it must be the VCR or it's interaction with the TV.

It is. That's a problem with all old TVs & VCRs, but not with DVDs.

As to the noise, it tends to be a tube-trait, but might be more of a Zenith problem. I think it's the horizontal oscilator, oscilating. Also could be a virbration in the HV cage.

As to the term "UHF STRIPS", it seems like Zenith kept using the same antenna connections LONG after UHF became standard. So ignore the term, doesn't apply to your set.

That set looks like 1970 to me... Might be a Chromacolor I?

We in the old TV word salute you sir for saving it. :thmbsp:

It depends on the DVD...some dvd's work ok on the old sets, but some have Macrovision and you get the old bending syndrome or you get lines appearing and disappearing at the top of the picture.

Nice Zenith! I recognize that model... two of my mother's sisters used to have one like it. I recall watching Forbidden Planet for the first time on one of those sets when I was a kid. There is also one of these sets in the local tv shop here. It will take me a lot of work to get to it because of all the crap that must be moved.

Looks like your set makes a pretty decent picture. Congrats! And, by the way... you'll be hooked now! :yes:

I CAN'T be hooked. I have no room for TVs. My garage is full of audio gear, I've got my closet packed with 6 pair of speakers, the kids rooms have a couple sets each, 3 in the LR, a couple in the Dr and a set in the MBR. My GF says NO to any more TVs'

Yes the pic on this one is good. Good enough that I've put it in the LR as a daily user.

Great find! The 20CC50 is from 1972 and is an excellent chassis. That chassis uses an IC for the color demodulator. Its always a good idea to check tubes even if the set appears to be ok. The 6Z10 audio output is normally a weak tube when found on a zenith, replace it and you will have a better sounding set.
Im glad another set like this was saved! Im sure you will take care of it, they deserve good homes. Those sets were the best in the world! (and still are!)

The unit had one of those little cylinders attached with the cable end on one end and two spade termainals on the other. The UHF strips were attached to the VHF antenna. There is also a UHF tuner terminal. I've got the cable running into my VHS. What now??

I also have a high pitched squeal that is just audible enough to be annoying. It seems to come and go.

It looks like the side panels are plastic so I guess the unit isn't that old.

Here are some pics.
You use a simple antenna distribution box, like RS used to carry under the Archer name. It has a center pair for input 300 ohm twinlead and 4 outputs the same. It is unpowered and usually had a piece of adhesive tape on it to attach it anywhere. All you need now is a 75 to 300 ohm balun to go in and you can run wires from two of the outputs for U and VHF or spend a few dollars more for a splitter instead with 300 ohm outputs. Depends on what you have lying around.

It seems to come and go and can be irritating if the volume isn't turned up loud. I have no TV repair skills(unless they are well hidden) and NO test gear other than a Realistic Multi meter.

If I decided to part with this unit , I know it would be preferable to keep it complete. What are these things worth? Whole or parts??

Ahh, but my dear Ken, You CAN get hooked on TeeVees ! You still got PLENTY o' room! Specialise in the "teeny-tiny" sets, such as Symphonic, Sinclair, the Panasonic 1.5" sets from the early '80s & the slighty larger 2" "Emerson"-style sets of slightly later. Whole bunch of those little guys don't take up hardly any room, & women generally find 'em CUU-UUUTE ! The "Lollipop" Sonys of the same era are collectable. Best things about these guys is lotsa times they work, & they're still relatively cheap,except the 1984 1.5 color Panasonic CT-101. Yes, I think the boffins at Matshushita must have known about the "CT-100" designation.Then there's the teeniest Trintron, the 1982 KV-4000s. Anyhow, you can still get into the wonderful world of One-Eyed-Monster collecting if you want... But be careful-one little guy gets lonely, so you gotta get a second, then you really want a micro color..just GOTTA have it...<grin>-Sandy G.

It seems to come and go and can be irritating if the volume isn't turned up loud. I have no TV repair skills(unless they are well hidden) and NO test gear other than a Realistic Multi meter.

If I decided to part with this unit , I know it would be preferable to keep it complete. What are these things worth? Whole or parts??

It's something not being properly filtered from the video stage, that's my guess. Old capacitors and an out-of-spec tube are probably the culprit, but I'm not a TV repairman either. Use the VCR and one of those godawful integrateds (like the one you had on top of it :D ) with some of those troublesome speakers you pile up :lmao: until you can figure it out.

If you ever want a SMALL TV (A REAL ONE) I have a National Panasonic AN609D 7" you can figure out. Robust CRT but needs caps and a diode or two in the PS (overvoltage to the heaters). It's an Instant On set so I could NOT let it run warm all the time like that, but it had a great picture and it's bright blue, as Matsushita was so famous for never making a dull set.

Send money, guns and lawyers and we'll smuggle it into Diefendorfer's garage without a further charge. (SP sorry I wish Bush was the other half of Anheuser some daze)..

PS somebody tell me if ~~~THIS~~~ National has anything go to with the Panasonic namesake?

making the squeal. It is there even when the volume is turned all the way down. The high pitched squel is emminating(sp) from within the TV, not from the speaker. The sound from the TV speaker is fine.

Steve....It's not an Integrated, it is a very nice Optonica receiver that is MINT with original manual AND Schematics. Only problem is it sometimes jumps in/out of stereo. Nice sound and a solid 85wpc. :D

Sandy....I've seen a few 4-6 inch tv's around lately in thrift stores etc. Some look like they also have a radio built in. may have been B+W. I am seeing a fair number of Sony Trinitrons around too, apparently a very good TV. If fixing TVs were easier than fixing audio components I may be inclined to look more for TVs. I think that's whay I've got so many speakers...they are relatively easy to repair or to just repalce a bad component. All I need is a multimeter and I'm good to go. :thmbsp:

Take it to the repairman then! It's not supposed to do that, but it doesn't sound fatal to the life of the set. STILL...it's not a good thing to operate it like that. Do that and ENJOY it!

making the squeal. It is there even when the volume is turned all the way down. The high pitched squel is emminating(sp) from within the TV, not from the speaker. The sound from the TV speaker is fine.

Steve....It's not an Integrated, it is a very nice Optonica receiver that is MINT with original manual AND Schematics. Only problem is it sometimes jumps in/out of stereo. Nice sound and a solid 85wpc. :D

Can you turn the muting off, and what are you using for an antenna? Does it only cut out on one or two signals? How is your antenna oriented in relation to the tall buildings in downtown Calgary?

Do you have a TV amplifier such as a CHANNEL MASTER, JERROLD or I even saw a nice Thomson made RCA once! A nice one with a rating of -22 or better and "90 mi+ urban fringe" VHF antenna should do the trick in your part of Alberta, and you can put it on an A/B swtich or an variable pot if you'd wish. I have 6 sets TV/FM/UHF scanners running at times and right now I wouldn't need cable to get 23 signals on TV alone (7 are digital), including two new in the last three months (!!!KKJB 39 is testing as of this week!!!)

I wish I could go to your place and build you a decent antenna system that doesn't rely on cable TV :yes:

I wonder if the squealing you're speaking of is the flyback transformer? Aren't they sometimes known for making a squeally-ringing sound... some more than others? I have '72 Zenith black & white set that makes an more than obvious high-pitch noise... moreso than others. It's done that ever since I got the set several years ago. It does, however, remain constant. I think you mentioned that yours comes and goes.

Seems I recall reading somewhere that shoving a piece of sturdy paper in the middle of the flyback can dampen the squeal. Anyone else hear of this? Am I on the right track here?

I think the golden cheroot goes to Charlie......flybacks seem to be pretty notorious on both Zeniths and RCAs.....at least in my experience. My hearing had big chunks of missing frequencies but I do hear some that are outside of the normal higher range due to a fused bone structure (or sumpthin like that).....anywho, I can actually hear some ultrasonic motion detectors in alarm systems. Because of this I drove RCA crazy with a new set I bought in the early 80's as it wouldn't stop squealing no matter how many flybacks they changed under warranty.

One repair shop thought they would put ME to the test and see if I was just a crack pot.....with the set on the bench and me just outside of the door so that I couldn't see it they'd ask me when I could hear it as they turned it on and off......of course they tried to fool me a couple of times but I nailed it 100% Shut them the hell up! And then there was the time I almost passed out from all the motion detectors in the Gold room at the old San Francisco Mint. Walked thru the doorway and nearly hit the floor from the instant dizziness that overwhelmed me. Shoulda sued da bums.

Anthony

I vote for flyback vibration. My hearing doesn't really extend very well up to 15,750 hz (horizontal sweep frequency) so I can't hear it usually unless it is REALLY loud (like on a few RCA's.)

I see on the portacolor I'm working on (replacing the flyback) it has a two piece affair with just a little layer of (rotten) foam between. No wonder those things ring! We have a 13" Samsung in the bedroom that works great but has a rather loud (but intermittent) flyback squeal. I would think there would be some way to calm it down, either with paper like was mentioned or something similiar. Just need to remember, very high voltage there, steer clear when the set is on & use some material which is not conductive in the least.

Wood shim.

Where do I find it, and do I just need to jam somehting beside it to reduce the movement of it? Remember, this is my first TV so about all I can ID inside it is the picture tube :worried:

I'll be sure to unplu it before I dig into it though...but doesn't something inside hold a charge for a long time even after it's unplugged?

I'll second Anthony- I used to hear the damn things, too. Never made me "sick", but some of 'em would cause me to exit whatever room they were in. High-pitched whine, kinda like a mosquito. Annoying as all get-out. I got told it was all in my head, too, mainly by older folks who really COULDN'T hear it.-Sandy G.

I called a Zenith TV shop around in town since the 60s. Asked if anyone still repaired a 30 year old model. He says he hasn't in some time but his fix to the flybak squeel would be some 5 minute epoxy to secure whatever is vibrating, his estimate....about 40 bucks. How can I find the flybak and verify that it is what is making thw noise. Would the epoxy cause any long term problems in repairing down the road?

I don't know if I would suspect mechanical flyback vibration just yet. Does the picture seem stable? Do you see jittering in the picture when you hear the noise? If so, then yes, you do have a vibrating flyback or you have HV leakage somewhere within the HV cage (the metal compartment on the right side of the chassis). Id be willing to bet you have a microphonic horizontal output tube. Some sets will make an unusual loud ringing noise when the elements in the horizontal output tube are loose. That set uses a 6LB6 horizontal output tube. Loose elements will vibrate at the horizontal sweep frequency and cause some weirdo sounds that are quite loud. Ive experience it before on my 20X1C38 console. The sound will change pitch and sometimes go away for a moment. This symptom will not cause picture jittering or distortion. While the set is on, take the eraser end of a pencil and tap the 6LB6 and see if you have any change in pitch. You can also take the tube out of the set and tap it and listen for loose elements. You will hear alot of ringing and jittering if the tube is bad (all tubes have this to a certian extent but some are alot worse than others) I have found RCA horizontal outputs to be worse than any other brand for this problem. I mainly only use GE, Sylvania or Zenith replacement tubes in all my sets.
But like I say, first check to make sure you don't have any picture jittering accompanying the sound, as mechanical vibration will almost always be noted on the screen. (picture jittering on the screen caused by flyback or HV leakage is called "piecrust effect" as a round shape will look like a pie crust if the problem exists)

I don't notice any change in the picture when I hear the noise. The noise doesn't really come and go. It is usually there but sometimes fades a bit and then intensifies a bit. As there is a tube layout attached inside the unit I'll try to check the tube. Maybe I'll look for a replacement tube.

thanks

Ken

Definitly sounds like the horiz. output tube causing the sounds from your last description. Check ebay for a 6LB6.
Doug

Or at least I think it was the 6lb6. I took the tube out and it does have a rattle when I shake it near my ear. Sounds like a burnt out light bulb. I can't see anything inside though. I do notice that not all the pins are connected. I can't verify which tube is which though as there are only zenith #s on them and the schematics is new to me. I put it bak in and it seems ok....for now. :thmbsp:

From earlier threads it would seem that the flyback would have some affect on the picture. The picture seems fine whenever the noise is there or not. In fact the pic is as good as any of the "new" TVs I have.