[AMRadio] 3-500Z 's as a modulator?

Patrick Jankowiak recycler at swbell.net
Fri May 28 23:14:03 EDT 2004

After buying several 304TH's and 304TL's, and out of five, 
finding only one to be good, I'm pretty sick of it. I don't know 
why I seem to end up with all the duds, but it's pretty frustrating.

-one had half the filament out
-two had a filament to grid short
-one flashes over at 500V plate voltage

I am thinking about the 3-500Z as a modulator. Any comments from 
the wisdom here?

At least I can buy them new and they will have a warranty.

I suppose sockets, anode dissipators, chimneys, and chimney 
hardware can't go bad, so I can't really get ripped off there..

Does anyone have a couple sets of 3-500Z socket/chimney/hardware 
they'd be willing to sell?

Looking for:

-two SK410 / SK410S or equivalent air system sockets
-two HR-6 (0.6" tall) heat dissipating connectors
-two SK406 chimneys and clips for the chimneys
-Pamotor 2000 or 6500 or equivalent blower that will do 13CFM at 
0.1" pressure or better

I also have a commercial RF deck with six extremely good 4CX250B 
tubes and blower (it's actually a puse amp) I would trade, for 
the above and a -guaranteed very good pair- of 3-500Z's.


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