I went through the chroma alignment. Only one adjustment needed tweaking. The set came without chassis hold-down bolts so I bought some that seem to do the job ok. I bolted the chassis and tuner in. About half of the plastic knobs snapped in half when I originally tried to pull them off. I used some epoxy for plastics and with some fiddling got them back on. I had to substitute an old knob for the color level control as it was missing. The UHF numbered dial indicator knob is missing. I only plan on using channels 3 or 4 but I'll keep an eye out for one if I can find a picture of what it looks like. I went through purity and convergence again. I still need to come up with a way to hold convergence pole pieces in alignment over the guns. Next I'm going to make mounting plate for a fan to get cool air into the HV cage. I plan to remove the rivet the access cover pivots on, remove it, and screw the fan plate in its place.

The first two pictures are of the fan I added to exhaust hot air from the top of the HV cage. The 12VDC fan is powered from the 6.3V filaments through a voltage doubler rectifier. I put the fan where it would exhaust the hot air generated by the HV regulator tube. There is a slot in the plastic plate that the fan mounts to. The slot is where the air enters. I epoxied a smaller piece of plastic to direct the cool intake air to the flyback first. So the flyback gets the cool intake air, then it goes by the HV rectifier, then the regulator heats it, the hot air rises and the exhaust fan pulls it out the top. I watched a 2 hour movie on the set last night and then felt the flyback right afterwards. The flyback was barely warm. :yes:

The last two pictures are of a ring of plastic with Velcro to hold the convergence pole pieces in alignment over the guns and to keep them from flopping over. The springs keep the pole pieces against the CRT neck but also made them want to flop over. Not the greatest solution, but it works ok.

Dave

This is a 3/4" wide Velcro wrap that I use for holding battery packs in my planes. I forget exactly what it's called, but it comes several feet on a roll. Seems to be self stabilizing, and you can tension it up a little.

http://i452.photobucket.com/albums/q...g?t=1424559278

http://i452.photobucket.com/albums/q...g?t=1424559276

Hey- that velcro wrap looks wide enough to be pretty stable.... Good thinking ! !
Simple fix too ! Always best.

.

Well it seems simple, but I'm not sure how critical the magnet spacing around the neck circumference will be? My cloverleaf is only broken in the one location, so it's throwing the magnet spacing off a little. I guess I'll find out when it's time to do a convergence. In the mean time it's doing a decent job of holding everything in place.

That does look like a better option than my fix. I was concerned about the spacing but now I'm not sure it makes that much difference as long as the two pole pieces of each convergence coil is over their respective gun pole pieces just inside the CRT.

Dave

Dave, that's good to know. One could take this one step further and put a piece of adhesive Velcro on top of each magnet assembly(similar to what you have) and then wrapping the strap around the outside. That should help stabilize the spacing.

Here are some pictures of the results of the restoration. The convergence is certainly a compromise. The multiburst shows video response through 3 MHz with 3.58 filtered out and maybe just a little at 4 MHz. I added a 22 uH choke in the screen circuit of the video output pentode patterned after a later Zenith set with a peaking adjustment.

Dave

Looks very nice from here. :thmbsp: Is the Ovation software by chance a free download?

Actually its an old DVD titled "Avia Guide to Home Theater" 1998-1999 by Ovation Software Inc.

Here are three pictures of the Zenith 29JC20 playing the Wizard of Oz. For comparison, here are two pictures (not quite of the same DVD frames) taken on my 21CT55 from a couple years ago with my same cheap camera. The Zenith has the 21FJP22A while the RCA has the 21AXP22A. I guess I would have to do a better job of getting the black and white tracking and the color tracking make a real comparison.

Many thanks for all the restoration suggestions and especially to Findm-Keepm for the ferrite cores. Two are now in the Zenith replacing broken IF and convergence cores.

Dave

beautiful pictures. a great job you done on the zenith.

that set looks great!takes me back to the old days and watching the new
zenith color sets at lazarus in columbus.

Wideband vs Narrowband Chroma
 

I have been sensitive to narrow band R-Y, B-y chroma verses wide band I,Q chroma since I got my 21CT55 up and running. This was my observation of picture quality based on a side by side comparison with a CTC 4.


When I bought my 21CT55 for $50 in '64, I brought it into the house after I got it working and ran it along side my Dad's old CTC4 he left me. Both had 21FBP22s so it was a good comparison of narrow bw color R-Y B-Y vs. full bw color I Q. The extension of full color into fine detail on the CTC2B was startling! Color persisted in fireworks until extinction which I never saw before. The CTC4 fireworks turned into white long before extinction. The CTC2B carried full color way into the shadows, the CTC4 went gray to black. I kept the CTC4 in the house for the kids but brought the CTC2B back to the garage workshop for further study. Ease of working on the chassis and CRT "forced" me to destroy the cabinet and configure the remains into the vertical chassis configuration I am blessed with today. That’s alright with me. I respect the original CT restores but that’s not my thing.

Thanks for the kind words guys. Your assistance to overcome difficulties with these old sets really helps.

Dave

I can only hope that my efforts give the results that your skills brought with your Zenith!

Looks great, good job!

Your set looks great and the picture looks great to. Good Job!!

That Velcro strap is called One-Wrap. It has hooks on one side and loop on the other. It work great for reusable cable straps instead of zip ties. I've used it for all sorts of things and once it's stuck to itself it's fairly strong.

That came out sweet. I always thought roundies had
the best pix especially with the older movies & anything period
from NBC. Bonanza will look even better than the Wiz.


73 Zeno:smoke:

The more I watch this set, the more I like it. The picture does not have the detail I see in my 21CT55, but it does have the full range of colors and a nice range of saturations. Its a pleasure to watch.

Dave

Looks great ! ! Good Job !

.

I'm impressed with the picture quality no matter what - Wizard of Oz, shows well! A pleasure to view, thanks.

If it is not too much trouble I'd be interested to see pictures of the tuners from inside the cabinet particularly the UHF tuner.

Here are the two pictures I took of them when I first started on the set. The first picture shows the VHF tuner from its right side (picture tube side when mounted in the set). The second picture shows the UHF tuner whose shaft is at the same level as the VHF tuner when mounted in the set. When I got the set the tuners were not mounted and it was missing its UHF tuning dial. I only use the VHF, which works quite well, so I'm happy. I can take more pictures of it mounted in the set if that's what you are looking for.

Dave

Nice tuner pkg. Even in the day we saw few U tuners
with a tube.
If you havnt swap out the 1st video amp tube even if it
tests good. It can make a huge difference in detail. They
tend to roll off at the higher freqs especially on Admirals.
They go from seeing no hair on a head to lots of hairs !

73 Zeno:smoke:

Thanks.
I have a UHF scale knob (not the knob you'd grab) from a later chassis. I don't know if it would fit your set, but I might be willing to let it go.

Cool, PM sent.