[Amps] Difference between 3cx800A7 and 3cx800U7

[Paul Decker]

Hello builders,

I've looked over the sheets for the 3cx800A7 and the 3cx800U7.   Besides the obvious mechanical differences, the data sheet for the U7 says the max plate voltage is 1800V with a 2250V rating with no signal while and the A7 is 2250.
I don't see any other major differences besides the maximum frequency rating.

Internally, is the tube the same with different mechanical packaging?  The reason  I am asking is because I have a U7 and a socket that I would like to use as a replacement for a bad A7 on 432 MHz.  My power supply (the one you all looked at yesterday) produces 2500V no load and ~2250V load.  

I suspect the 1800V limit applies because the intended service for the U7 is above 800MHz and it should work fine with 2250V plate at 400 MHz.

Is there any real differences?  What is the groups opinion?

Thanks,
Paul
kg7hf