Tube Swap Question

moonchilddave

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I thought I had seen on here a link where you could enter a model number of a TV and find out what model picture tube it had (or at least what socket) - but I can't find it again. The particular TV I'm looking at is a Zenith SMS1943S, and would be going into a 4900 chasis.

It's a little out of my way, and they want $30 for it - which I wouldn't mind if I knew for sure it would work (and I might be able to talk them down on the price). I asked if they could check the tube number for me but they didn't want to open it up.
 
I've seen that site before, but he only had like a dozen sets listed. Honestly, there are so many hundreds of different models of television out there, that it's going to be very hard to document all of them. The best way to find out is always to open the back and look for yourself. But, you can get a good idea just by looking at the outside. You need to be sure that:

- The set is a 19" (not 20", as some newer sets are).
- The tube has the usual amount of curvature, and isn't flat faced or closer to flat than usual.
- Sony Trinitron sets won't work.
- It's an inline gun set, not delta gun. Delta gun sets will be pretty old (early 70's), although I think RCA made a couple into the 80's. You can tell by looking closely at the tube, you want the individual phosphor groups to have their dots aligned in a horizontal line, not in a triangle. Delta gun sets also have large, complicated convergence assemblies inside, with at least six pots, possibly a dozen.
- Looking inside, you want to ensure that the neck connector looks the same as your arcade chassis.
- Some Zenith sets have the convergence rings in the same plastic assembly as the yoke. This is a bit of a pain because you have to replace that convergence assembly, thus requiring you do a full convergence setup. Most other sets you can just slide the rings off and then put them back on when you swap the yoke.
- If you have a tube tester, test the tube before doing the swap. I've found a couple sets that had weak/dying picture tubes. It's pretty rare, but good to check for if you can.

But, the short answer is that from my experience, most 80's era 19" sets have usable tubes , even some of the early 90's ones. In any case, you shouldn't have to pay $30 for an old TV set. You should be able to get them nearly for free.

-Ian
 
Some Zenith sets have the convergence rings in the same plastic assembly as the yoke. This is a bit of a pain because you have to replace that convergence assembly, thus requiring you do a full convergence setup. Most other sets you can just slide the rings off and then put them back on when you swap the yoke.

Zenith TVs seem to have a high rate of compatibility. When I get the yoke+rings assembly, I take a Demel and carefully cut the ring part of the assembly off.
 
Here's my site (that I hope you're talking about): http://www.junknet.net/donor-tvs

Zeniths are VERY compatible and prob the best ones to aim for. The fact that it has 19 in the model number is a good sign. I'd say jump on it.

If you do get it, please send me the tube # and readings off the yoke and I'll add them up. I think I have 2-3 others to add as well.
 
Zeniths are VERY compatible and prob the best ones to aim for. The fact that it has 19 in the model number is a good sign. I'd say jump on it.

If you do get it, please send me the tube # and readings off the yoke and I'll add them up. I think I have 2-3 others to add as well.

Yeah, I'm gonna go pick it up later this week, I'll let you know how it turns out and get you readings to add to your site if it's a keeper. BTW, talked them down to an even $20 for it. Not free, but still a deal if it turns out to be usable - which everything I've seen seems to lean that way.
 
Went and picked up the TV last night...

TV: Zenith SMS1943S
Tube: G-A48ACB02X

Yoke Readings:
Horizontal (Red/Blue): 2.1
Vertical (Grey/White): 8.6

Yoke Readings taken with a Fluke 87 DMM.

Looks like this has a good chance of being a drop in replacement for a k4600?

BTW, how can you tell the difference between the 4600 series? I have 2 different ones this tube could go into, but I don't know how to tell what the exact model of the chassis is. I noticed that the 4603 has a horizontal reading of 4.4 - so this tube might not work in that one without a yoke swap I'm guessing.
 

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