New Roundie sets scored

[Glenz75]

If I ever plan to travel to the US some day you guys will be the first to know.... I expect a 'full demonstration' of a colour roundie, a Zenith porthole and one of those cool RCA Projection Sets and more plus a road trip to an old TV shop thats been locked up for 30 years...Am I asking too much??....

Originally Posted by mstaton

If you are ever in the US, I'm sure anyone here would be happy to show you one. Working condition no doubt.

[miniman82]

If you can cover shipping, I have a cheap Philco roundie with a good tube looking for a home...

[Glenz75]

I'd hate to think what it would cost to ship a set to New Zealand....Hmm tempting though...

Originally Posted by miniman82

If you can cover shipping, I have a cheap Philco roundie with a good tube looking for a home...

[Electronic M]

I'll make the prediction that by the end of this century that any CRTs with their original cateracts will have completely lost the CRT to safety glass bond, and likely have the PVA turn to dust ,fall off on it's own, or be in a state where it can be removed by hand(or finger nails). That is my take.

damen
I pulled the CRT I thought it was going to be the non bonded glass front that needed to be cleaned between it but it was a cataract all the way threw the lens fell off when I removed the tape so I cleaned it up and reinstalled the lens with black foam weather striping and tape and the set looks much nicer

Shoot! My prediction came true faster than I thought possible.
Hmmm, now what other nice nice things can I predict..... mmmbuhahaha



Nick, if he passes on that Philco, and the price is right I could probably give it a home.

Glenz, here is a couple photos of my roundy running.




We now return you to your regularly scheduled programing....

Tom C.

[Glenz75]

Thanks for those photos EM From what I've seen of your early sets the picture quality looks really good and such natural colour, those colour bars pretty much say it.

Originally Posted by Electronic M

Shoot! My prediction came true faster than I thought possible.
Hmmm, now what other nice nice things can I predict..... mmmbuhahaha



Nick, if he passes on that Philco, and the price is right I could probably give it a home.

Glenz, here is a couple photos of my roundy running.




We now return you to your regularly scheduled programing....

Tom C.

[sampson159]

love the pics!that roundy looks as good as it did when new.

[Electronic M]

Those pics are before I had and fixed a vertical failure. The gray scale is slightly off now but still good. I also have always had what I think are drive bars that I have to get around to trying to fix. The focus tends to vary with scene content (which also reaks havok with convergence). Most of these problems don't show in photos, but are just bad enough to bug me in person so I still have work left on this set.

Glad you liked the pictures.

Tom C.

[ctc17]

Do some research, you will find a flyback you can sub in there if you are willing to spend the time. It will most likely require changing the bracket and maybe changing some of the wiring around but it can be done. Zenith is one of the tougher ones to sub so look at other Zenith sets for something similar.

[mstaton]

This is the first set out of the ones we picked up in Seattle. It is a CTC-16XL from 1966. I removed the cataracts and reinstalled the CRT and cleaned out the cabinet. Not too dirty. The chassis was very clean. It needed several tubes. All the caps check good. There was some bad solder so I went over all the boards carefully and re-soldered anything that looked flaky plus all the grounds. I cleaned all the controls and tuner. I was rewarded with a raster and a very decent picture. It will need a convergence touch up. I checked the cathode current and its about 208ma, I made a permanent jumper for convenience on a small terminal strip. I made some minor adjustments to the vertical height, horizontal centering and grayscale. I set the HV to 24KV as per Sams. The electrolytics stay cool even after several hours of running. This is a very easy chassis to work on. Much easier than the CTC-9. here are some pics

[DaveWM]

I like the CTC-16, very easy to work on. I routinely replace the HOT coupling caps (think there are two a .01 and a .0068 IIRC), the 1kv caps on vert and audio out transformers (white ceramic tube caps). The .0082 1kv vert out plate cap. I do the 1kv just cause I cant really test them with my cap tester.

Then there are the 3 .01 coupling caps in the 6GU7 grids on the chroma board. the one that is right next to the tube and a power resistor ALWAYS test weak, the other two generally test ok, but I replace them anyway.

I also like to replace the .1 video coupliing cap to the 12xxx video out tube, and the .1 in the AGC (just because AGC is a pain if its not right). All the hi value lower volt brown drops are suspect, but if they sit right next to a heat source I like to check them.

[mstaton]

I will order all new caps sometime in the future. right now it works very well.

[DaveWM]

Yea no hurry, I have replaced those and had no visable change. the only one that I really matters is that HOT coupling cap, if its leaky at all it will cause the HOT current to be high. I like to use a VTVM to check the neg voltage at the grid, and a scope to check the PP.

[ctc17]

Just checked the cathode current on my 16xl today. 180ma, lower your line voltage a little. I wish there was an easy way to run these with the fly cage open because the thing just cooks in there. Im tempted to bend the lid 180 so its pointing up when closed. Some people cut holes and put fans. I dont like the idea of fans because thats forced dust injection, I do however try and run all my sets with the can open. Lowers the flyback temperature by about 80 degrees

[mstaton]

I have no easy way to lower line voltage. Line voltage is 120V. I suppose you can add a filter to the fan to keep dust down. It's almost hard to believe how good of a picture these can produce when working correctly. I'll check the current again tomorrow and readjust if necessary.

[ChrisW6ATV]

Originally Posted by mstaton

I have no easy way to lower line voltage. Line voltage is 120V.

Look up "line buck" and autotransformers. You can rig something like a 6-volt, 4-amp power transformer to cut the line voltage down by 6 volts for up to a 480-watt TV. Essentially, you connect the transformer's primary and secondary to cancel itself out and put the TV in series with the result. There was a discussion of this either here on VK or on the antique radio forum recently.