[GreenKeys] Western Union Rectifier 69-B

[Derek Cohn/WB0TUA]

Hi Everyone,

Last week, I picked up this power supply from a local eBayer.  It says Western Union Telegraph on it but it may be a TTY supply (not sure).  Either way, I think it should work fine with my morse circuits as long as I keep the current down at 60 ma where it belongs.

Here are some photos:

http://www.mindspring.com/~vibroplex/tty/WUPSLABEL.JPG

http://www.mindspring.com/~vibroplex/tty/WUPSFRONT.JPG

http://www.mindspring.com/~vibroplex/tty/WUPSSIDE.JPG

http://www.mindspring.com/~vibroplex/tty/WUPSTOP.JPG

http://www.mindspring.com/~vibroplex/tty/WUPSOSIDE.JPG

http://www.mindspring.com/~vibroplex/tty/WUPSBACK.JPG

I have a few questions....I have not traced the wiring yet my thinking is that the cardboard tube rectifier is probably not original.  If anyone has one of these, I'd appreciate your thoughts on that rectifier (which probably is dried out and needs to be replaced).  I see a crummy solder joint on the oil bath capacitor behind the choke.  My guess is that someone removed a lead to test it, found it bad, and then added the one in the cardboard tube behind the transformer.  the one in the cardboard tube is 75 uf.  Does that sound about right if I replace it?  

Also, there is an adjustable wire wound resister tacked onto the terminal board at the top of the power supply.  My guess is that the current was too high and this was added to get it down lower.  The label says .6 amps which sounds to me to be too high for a typical Morse or teletype circuit (unless there were a lot of instruments or teletypes on it).  Looks like the wire wound resistor is almost shorting against the input terminals so that needs to be repositioned (and possibly replaced for sure.  

The 83 mercury vapor rectifier in it looks pretty shabby.  There is some material flaking off the plates and scattered all over the tube.  A friend of mine who sells tubes for a living says this is pretty common with 83s and that they generally still work as long as the material is not conductive/shorting some part of the tube internally.

Anyway, if anyone is familiar with this power supply or can give me any more information, I'd be interested in hearing from you.

Thanks and 73,

Derek Cohn
Amateur Radio Station - WBØTUA
Morse Telegraph Club - Office UD, Sine DJ
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