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Electro-Matic Chuck Rectifier Help Needed

Brianison

Aluminum
Joined
Aug 28, 2015
Hi folks,
I've got an old Electro-Matic vacuum tube chuck power supply that just smoked a rectifier tube. I have a n.o.s. replacement tube on the way,( got lucky, and found a pair on fleebay). So I thought while I was at it I'd try to find a spare for the other tube in the circut.

Problem is, it's an RCA 8-pin tube, but the identifying number is no longer visible on the tube. I'm hoping perhaps somebody out there might still have one of these units, and be willing to peek inside, and tell me what number is on their tube. I know it's a long shot but stranger things have happened.

Electro-Matic is still in business, but when I called their service dept. I was told that they no longer offered support, or information for their older models, and replacement would be the only help they could (or would) give.

Here is the nameplate info on the unit: Electro-Matic Model M42T Serial #23937

DC 230V AC 460V

500 Watts 50-60 Cycle

I plan to engineer a solid-state replacement for the tubes eventually, but for the short term I need the machine running, so I can buy some time to do that.
 
yea, problem with electromatic is they do not support much......

your best bet may be to just find a newer/used unit on ebay. there are a ton of these out there.

Another item that goes bad is the dc motor that runs the cycles for on/off/demag.
 
After a dogged search of the internet, I was able to figure out that it's a # 2050 thyratron tube. Commonly used in the way an SCR is today, it was a common tube in it's day, and still widely available. One of it's more notable uses was in Seeburg juke boxes.

SO for the record, and to help anyone else with one of these units the tubes in mine are: 2 National Electronics #NL-617 rectifier tubes, and 1 #2050 thyratron tube.

Take that, Electro-Matic ! Your superior intellect is no match for my puny weapons!
 
For those not overly familiar with electronics...
Replacing with a full wave rectifier is pretty easy.
Rectifiers come with the leads labeled.
There are 2 AC leads and a DC+ and a DC-.
Just get one with enough amps (watts, whatever) capacity
and wire it in. The hardest part is reverse figuring out
what leads on your controller are what. Usually AC in is
pretty easy to identify, and that just leaves DC out.
Don't be too afraid of it. Hunting tubes is pretty old school.

-Doozer
 








 
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