Has any body replaced the selenium rectifier in the
CT100 with diodes?Info appreciated.

What's the name of the parts house in Pennsylvania
That carries a great deal of old stuff. I think it
Starts with an M

Why, have they gone bad?

You're thinking of http://www.surplussales.com/

What's the name of the parts house in Pennsylvania
That carries a great deal of old stuff. I think it
Starts with an M

Moyers -----> http://www.moyerelectronics.com/Departments/Products/Vintage-TV-Parts.aspx

This previous thread (http://videokarma.org/showthread.php?t=86876&highlight=selenium) discusses the selenium issue.

Looks like the votes are about evenly split between replace vs. leave alone. FWIW, the previous owner of my CT-100 did replace the seleniums. If you replace 'em, disconnect the old unit completely (that is, don't wire the diode in parallel).

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

If you replace 'em, disconnect the old unit completely (that is, don't wire the diode in parallel).

Why not? The seleniums when they go, don't they simply open (go high resistance)?

Some times they short and relese toxic selenium gas.

Believe it. I've experienced shorted selenium(s) clearing out a shop.:tears:

Why not? The seleniums when they go, don't they simply open (go high resistance)?
They develop reverse leakage also.

I had once case where a selenium smoked real bad, and the only thing that went open was the windows, and they stayed open for about a week

If you use them, fuse them.

I've had good luck with old test equipment and radios that use them, but not in TV's where they see higher loads.

John