[AMRadio] ceramic tube tester


H.L. hl at sfsu.edu
Thu Oct 9 19:30:26 EDT 2008


I finally got my 1966 TMC linear amplifier operating, but with a 
modulated AM (MCW) input, my Wattmeter indicates an anemic 25 Watts 
into a dummy load with a total PA plate current of 200mA (nominal 
current reading according to the manual) for the two parallel 
4CX250b's. The manual claims 200 Watts CW! Perhaps one or both tubes 
are weak. Perhaps a resistor or capacitor has changed value. I just 
don't know yet and may have to put it on the bench again.

If anyone knows of specific tube testers that will test ceramic 
transmitter tubes, such as the 4CX250b or the 4CX350a, please share 
them with this list.  Many amplifiers and transmitters use these 
tubes.

73 Hal KK6HY

P.S. I am still interested in TMC transmitter and amplifier original 
prices to share with the group.  So far, no one has responded.  TMC 
certainly seems to have kept their prices well hidden.


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