My Motorola Project: "Television Impossible"

[Kamakiri]

Well, at least it is for me

I've got a pair of 1952 Motorolas, one 20" tabletop model 20T3, and one 21" beautiful blonde console. The tabletop was a $20 garage sale find with a trashed cabinet that I bought for parts. The chassis was intact, but the picture tube was toast. My console had a perfect picture tube, but the chassis had been cobbled together over years of part replacement, then as it seems, the replaced parts were removed, leaving an unholy mess underneath the chassis. My project: make one set out of the two. Both use a nearly identical chassis, same controls, same tube complement, so let's go to work!

After stripping the 20T3 chassis of tubes and dead picture tube, I set out to start recapping the set. After years of mounting the caps under the chassis and securing them with twist ties and black tape, I decided on this one to go top mount with the caps, using perforated circuit board. I removed the old caps, and drilled through the chassis to top mount the cap boards with pop rivets. Looks neat and clean



Here's a view from the underside. I ordered all the caps from Digikey, which has stickers with the value of every cap on the bag. As I desoldered each lead on the old multi-value caps, I placed the sticker on each wire so I'd be able to easily identify which wire went to which cap.....because as we all know, the leads going to the cap are pretty short. This enabled me to dismount the old cap without having to knot certain wires or make some kind of hieroglyphics to try to remember which wire went where

Turned out pretty good.....



Then I removed the lower chassis cover and saw this. Ugh......



What are the odds this flyback is still any good?

[Kamakiri]

Now, let me pick your brains on something else. The set had a 20CFP4 picture tube, and a 21FP4C is going in its place, using the chassis mounts from the other chassis. The chassis I'm building is a TS-307, and the parts chassis is a TS-292A.

I do know that the flyback in the parts chassis is good. Think I should swap them out anyway? Can anyone forsee any issues with the project as a whole, with the exception of just the usual worn out componentry?

[ctc17]

I have seen some realy melted flys that work fine. That almost looks like a home re wax job. Give it a try

[AndrewM]

The flyback looks ok. It has been given a very heavy layer of wax to seal all the connections to prevent arcing. I'd try it first before thinking about replacing it.

[init4fun]

I'll have to agree with the guys who say to try it first ...... In our human world , as we're all painfully aware , looks really DO matter , , but to electrons , a good path is just as good no matter HOW ugly the surroundings

Great job with the perfboard on those capacators , , I'll be borrowing that smart idea for my next recap ........

[Eric H]

I think the yellow wax is factory, first because the tire looks perfect, second it couldn't contain that much wax in the first place, last it would have dripped down onto the cabinet, not all over the board like that.

I've seen other NOS flys with wax like that covering the board, not quite so much but it was there.

[Kamakiri]

Hm. Interesting. Well, onward and upward then! Will post more updates as work progresses

[Username1]

I have seen that kind of wax job on a magnavox, but the wax was black, and if it melted from the transformer to the board it would have had to move horizontal so it was factory, and it was our family set so I know it was original.

[M3-SRT8]

Very clever with the perf boards. I used it on some of the 'lytics replaced on the very first TV resto I did, a 630TS. After that, I pretty much went the restuffing route. I like how neat yours looks. You did a nice job...

[Kamakiri]

If I was redoing something like a CT100, I probably would have went with an under-chassis mount somehow. This set, while being in very nice shape, isn't something rare or historically significant that I feel that I'd need to keep a dead stock factory look. My goal here is to build a set that will last until after the apocalypse, so that in hundreds of years when insects rule the Earth, they can tune in to some programs, provided they grow the proper opposable thumbs.

No, not really, but it sounded cool . I just want to build this set to last. I had thought of replacing every resistor under the chassis as well as long as I have the thing apart, but I think that I'll just replace those that look as if they've deteriorated, and get a baseline to see where I'm at once this is done.

[Kamakiri]

Decided to resume a little work on the set. Immediately something didn't make sense.....

I ordered the caps from Digikey off the schematic, and something looked immediately wrong. Hm, seems the set doesn't have this many. Am I missing something?

I sure was. I had the chassis model wrong. It's a TS-351. D'Oh!

So, it's back to fleabay for another sams. Meanwhile, I changed all the chassis brackets and the yoke over from the old chassis and test fit the picture tube.....




I did notice that underneath that just about all of the larger resistors are cracked in half. Wonder what kind of catastrophe caused that kind of cascade failure.....

[stereorob]

what a nightmare! maybe it got hit by lightning or something? hope you can get her glowing again. those are really neat sets.