Zenith 19EC22 4-tube hybrid

[radiotvnut]

I just got a 19" Zenith 4-tube hybrid 19EC22 from the same man that I got the RCA combo and CTC38 metal table set from. The set needs a major cleaning, the channel knobs are missing, and the back was not screwed on. Nothing appears missing off the chassis. This looks like an entry level model as it does not have a chromatic or afc switch. This looks like it could be one of the later 4 tube sets. I'll post pictures when the camera battery charges.

[radiotvnut]

Here's the 19EC22 Hybrid. Does anyone have a picture of the correct channel knobs for this set? I've got a box of knobs; but, don't remember what the ones looked like for this model.

[drh4683]

You have the very last 4 tube hybrid. Im pretty sure all 19EC22's had the detented UHF tuner. Take a look tward the end of "estate sale finds in 2007". I picked up a 19EC22 last december, you can get an idea what the knobs look like. They are basically chormacolor II knobs.

[Carmine]

Not the greatest picture of the knobs, but I think they look like this...

[radiotvnut]

It's an F4001W1 and I found a date of '74 on the delay line. I fired it up and was greeted by no vertical deflection caused by a busted service switch. I jumped the switch and got a nice, bright picture. The sound is also very weak and distorted, probably due to a bad audio IC and there is HV leaking from around the tripler. It's already been patched with RTV. I'll probably replace the tripler and focus bleeder with an ecg526 or 523. I think that should work. This is like the other Zenith's I used to bring home: never totally dead!

[radiotvnut]

Here's some more pictures of the knob area & chassis. The UHF fine tuning knob was all that was left. The top knob was one I borrowed off of a '76 CCII. The UHF tuner in this set is not the click stop type. And, I can't find my box of knobs. That's the way it always works. Something's there until I need it!

[radiotvnut]

I found the Sams (1413-3) and the knob part numbers are:

UHF channel selector - 46-8884
VHF channel selector - 46-9223
VHF fine tuning - 46-4982
volume - 46-9413

[jpdylon]

GIve me a day or two to look through my spare box of knobs. I think I may have at least the VHF knob...

[radiotvnut]

After connecting the cable and paying better attention to the picture, I noticed it was smeared and the contrast was poor. The problem turned out to be C213, a 25 uF non-polarized electrolytic cap. I thought I'd pass it along in case someone else encounters this problem.

Now, I've got to repair the convergence board. The blue convergence is way off and won't adjust. This board does not use the usual Zenith rectifier assembly. There are four glass diodes on the convergence board. That's on my agenda for tomorrow.

The audio problem turned out to be a very dirty volume control.

This set is well on the way to "daily watcher" status.

[radiotvnut]

Jpdylon, thank you for looking for those knobs for me. I still have not found my stash. I guess I hid them from myself!

[drh4683]

Id be surprized if one of those diodes were bad, but it has happened. How is the blue left side convergence control? Lots of times those overheat and burn up. The blue shaft would be brown nearest the pot from overheating. I think those overheat though from leaky x6d diode. You'll probably have to pull each diode from the circuit to test. Lots of them have very low resistance shunted over them.
Be prepaired for loosing color from the left side of the screen. It happens on many 4 tube hybrids. Its a bad (high esr) 100uf@35v lytic from the 24VDC supply to the chroma duramodule under the chassis. You might want to check that one before going any further. Its usually a foreign made cheap cap, either gray or orange in color.

[radiotvnut]

I went ahead and changed that 100 uFcap for good measure. I would like to ask a question concerning the tripler. This uses an ECG500A (6 step tripler). An ECG523 is a 6 step with the focus bleeder built in. I think I should be able to use the 523 and do away with the seperate focus divider; but, wanted to ask here just to be sure. The one in there has been RTV'ed to death and it's still got a leak somewhere. I'd feel better if a fresh tripler were used.

[radiotvnut]

I'm not done yet; but, here's some pictures of the set in operation. I still have to play with the convergence & purity some more. The vertical height & linearity need to be adjusted. Even though I'm not done, it looks better than most modern imported 19" sets.

[freakaftr8]

I'd say nice job! That is turning out to be a great little set you got there!

[jpdylon]

Couldn't find the appropriate knobs for that set. I must have used them somewhere else. I had a set similar to that I picked up for about 5 bucks a little more than 6 years ago. It served me well and had a glorious color picture until the vertical output tranny died.

Great sets.