[Amps] 3-500Z uses [TSPA]

[John T. M. Lyles]

My coworkers and I maintain some five 'sockets' for 3-400Z at work, 
each used as an inverter/driver for a 4CX3000A which screen modulates 
a pair of 4CW250,000B which are plate modulators for a Burle 7835 
grounded grid triode. So, we haven't even modernized up to 3-500Z, 
but hope that at least Amperex/Covimag continues to make their 
version.

At home in the shack I have a Continental 314R1 BC transmitter under 
conversion to amateur AM serivce. It uses three 3-500Z triodes. In 
talking to the service folks at CEC, they believe about 800 of these 
rigs are still operating world wide in AM stations. They are 1980 
vintage PDM design.

For me it would be hard to believe that the source of 3-500Z would 
vanish entirely, as there are many industrial uses, such as LF 
induction heating, and wierd modulators and gadgets such as mentioned 
above.

73
John
K5PRO