View Full Version : 1972 Zenith Hybrid


davet753
03-24-2020, 03:35 PM
Note: I should have posted in the "rectangular screen color TV" thread, but now that the post is up I can't figure out how to move it or delete it and start over. Mea culpa.

My new 4 tube Zenith hybrid portable. Exactly like the one I grew up watching at my grandparents home. Thanks to a local tv collector and friend of mine, who generously offered to part with this set, my search for this model has ended.

It had never been serviced and had all the original tubes. I replaced the horizontal output, damper, and vertical output tube along with a few electrolytics and it came back to life good as new after a few adjustments and a good tuner cleaning. It's a 19CC19 chassis; made the same year and month I was born in.

Out of all the televisions I’ve serviced, I always thought these chassis were about the best ever built.

Electronic M
03-24-2020, 04:49 PM
Note: I should have posted in the "rectangular screen color TV" thread, but now that the post is up I can't figure out how to move it or delete it and start over. Mea culpa.

My new 4 tube Zenith hybrid portable. Exactly like the one I grew up watching at my grandparents home. Thanks to a local tv collector and friend of mine, who generously offered to part with this set, my search for this model has ended.

It had never been serviced and had all the original tubes. I replaced the horizontal output, damper, and vertical output tube along with a few electrolytics and it came back to life good as new after a few adjustments and a good tuner cleaning. It's a 19CC19 chassis; made the same year and month I was born in.

Out of all the televisions I’ve serviced, I always thought these chassis were about the best ever built.
Nice score.
I keep hoping I'll find one of these table model 4 tube hybrid Zeniths.... closest I've gotten so far is a rusty module-less parts chassis...

The red and white triangle in the top corner of your post allows you to report your post to a moderator and ask them to move it to the right section... I've already asked them on your behalf.
You can click on that triangle in other people's posts and report spammers or people who are harassing you. The more you know...the less GI Joe can cuss you out on the internet.:D

davet753
03-24-2020, 05:08 PM
Thank you, sir. I appreciate that.

I got out of the repair business in 1998, but I had been looking for this model hybrid Zenith for several years before that. I was willing to settle for anything close, so I was pretty excited when I found the exact one I wanted.

I was amazed at how well this performs after being shelved for an untold number of years. I had it on for several hours today, and the picture keeps on improving as the CRT wakes up from it’s nap.

JohnCT
03-24-2020, 06:21 PM
Note: I should have posted in the "rectangular screen color TV" thread, but now that the post is up I can't figure out how to move it or delete it and start over. Mea culpa.

My new 4 tube Zenith hybrid portable. Exactly like the one I grew up watching at my grandparents home. Thanks to a local tv collector and friend of mine, who generously offered to part with this set, my search for this model has ended.

It had never been serviced and had all the original tubes. I replaced the horizontal output, damper, and vertical output tube along with a few electrolytics and it came back to life good as new after a few adjustments and a good tuner cleaning. It's a 19CC19 chassis; made the same year and month I was born in.

Out of all the televisions I’ve serviced, I always thought these chassis were about the best ever built.


Worked on a lot of those bad boys over the years.

Resist the urge to do a dynamic convergence if you can help it. The convergence coils run hot by design and the blue plastic bobbins turn to cracker over time. One turn with a hexaligner and the coil is unspooling itself across the floor as you chase it swearing up a storm. The wirewound pots are also prone to disintegrate when turned.

John

davet753
03-24-2020, 07:17 PM
Worked on a lot of those bad boys over the years.

Resist the urge to do a dynamic convergence if you can help it. The convergence coils run hot by design and the blue plastic bobbins turn to cracker over time. One turn with a hexaligner and the coil is unspooling itself across the floor as you chase it swearing up a storm. The wirewound pots are also prone to disintegrate when turned.

John

I saw quite a few come thru the shop when I first started, but they were reaching the end of their useful life. When the price of 20LF6's shot sky-high about 1989, these models were tossed pretty fast.

The blue convergence was off, but a slight turn of the blue thumbwheel adjustment on the convergence yoke brought it back in line. You're right about the convergence coils; I wouldn't want to chance one disintegrating trying to turn it. I had to adjust the vertical linearity, size, and centering...and I held my breath when turning those pots. Fortunately, this looks to be a pretty low-hours set, so it all worked out fine.

It's been close to 30 years since I've had one of these sets on the bench, and it was fun to get it back up to snuff again. I even remembered how to adjust the APC on the colorburst module (flip the switch and adjust for minimum movement of the color bars). Odd I can remember stuff like that from years ago, and I couldn't tell you what I did last week.

bgadow
03-24-2020, 08:52 PM
If we made a list of the top 10 best televisions of all time the Zenith 4-tube would sure rank very near the top. Every one I ever stumbled upon worked as found, and worked well.

JohnCT
03-25-2020, 05:00 AM
The blue convergence was off, but a slight turn of the blue thumbwheel adjustment on the convergence yoke brought it back in line. You're right about the convergence coils; I wouldn't want to chance one disintegrating trying to turn it. I had to adjust the vertical linearity, size, and centering...and I held my breath when turning those pots.

Don't worry about the chassis controls, they're fine. The "DC" adjustments on the convergence yoke won't give you any trouble either. It's just those parts contained on thy dynamic convergence board that are problematic because the heat is contained in a small area.

There was one series that had a bagged kit from Zenith to rebuild the convergence board. Came with coils, pots, and a 5 watt resistor IIRC.

John

zenith2134
03-25-2020, 01:05 PM
The 19CC19 4 tube hybrid is my favorite Zenith color chassis. I watched one daily for years; and still have it somewhere but am using my 19" K-line Zenith with the upright Chromacolor II chassis from '78 as my daily set now. Both produce an incredible color picture, as long as the CRT has strong emission and the demodulator is functioning properly. Yes, that '72 is the "zenith" of chassis construction in many ways. They always turn up still working on the original tubes.

davet753
03-25-2020, 05:03 PM
Mine worked somewhat with the original tubes. The vertical sync was shaky and the size control had to be maxed out, plus it took a minute for the horizontal to fill out, but it did function. Three tubes checked out near the bottom of the good emission scale, so I went ahead replaced them. The 6U10 checked pretty good, so I left it in.

Since this is one that I never intend of letting get away from me, I wanted to make sure it was performing darn near perfect.

zeno
03-25-2020, 07:43 PM
The 4 tuber was what I cut my teeth on. It was a great teacher. Learn it &
you know how to fix flat chassis & upright CC2 sets. They were all the same
with tubes switching over to transistors. Theory of ops the same otherwise
with almost the same parts & design. Evolution at its best.
I also remember part #'s like 63-9115 vert size control, 9-27 color module,
78-1888-01 damper tube socket & 883-13 double sided sticky tape to mount
the yoke ring. At the time I probably knew 20 pn's for small parts. If you
look at the damper socket at one time I knew the pn's for the grommets,
plastic rivets, big cap under it & the spook coils, good to know when one
really burned up. Now I can only remember what what I ate for breakfast
because I never eat breakfast !

73 Zeno:smoke:
LFOD !

davet753
03-26-2020, 08:41 AM
I know what you mean, Zeno. Once I took this one apart, I slowly started remembering problems I had fixed in the past, plus a childhood memory.

My grandparents had this model Zenith for years. When I was a kid, I was always interested in electronics and one day when my grandmother was out, I told my grandpa I wondered what was inside the tv. He promptly fetched a screwdriver and we took the Zenith apart to explore it’s innards. Of course, me being about 7 years old, I didn’t know a tube from a transistor.....I just knew I wanted to learn how it worked. It was a good time until granny walked in and found us in the floor with the tv apart. She put an end to our little project in a hurry.

My grandpa done more to encourage my curiosity about how things worked than anyone else. It didn’t matter if it was the tv, the iron, or the mixer, he was always ready to go along with me when I wanted to take something apart and see what was inside.

JohnCT
03-26-2020, 12:52 PM
One more thing I recall about the hybrid Zeniths: the horizontal output tube often had a blob of black RTV low on the glass and on to the chassis to keep the tube in the socket during shipping.

John

DavGoodlin
03-27-2020, 10:00 AM
Dave- That is a very worthy keeper!

I had one of the first versions, chassis 4B25C19 with same knob set and rocker switches for power and afc. I was thoroughly enjoyed in my first apartment away from home at tech school. The apartments location was so awful and 55 miles from Phl, you HAD to get cable and this TV with its SS IF brick module lent itself to some creative trap tuning that allowed mid-band sine-wave scrambled cable pay channels to be locked in.

I had to sell it for rent money when I got laid off at the Sylvania dealer, winter 1982 when times were tight. I got $125 for it, with stand and trap settings restored. A fine model from which others we made.

I currently have a 19DC20, a model year later but with the 1970 Chromacolor knob set. This one was from my neighbors hunting cabin, after analog shutdown. Up till then it was on one channel they got in the hunting grounds, WBNG-12. The CRT looks like it was not used hard but the vertical was maxed out and still short as most are while plugging away.

sampson159
04-01-2020, 11:59 AM
those sets were built like tanks.when they were 5 to 10 years old,they were our best selling model back in the shop days.if we wanted to sale some of the other more newer sets,we had to move them across the room.didnt want them anywhere near those zeniths.