[Amps] Any designs for 4CX1000A on 2m

[John Lyles]

That's impressive, I wonder how far they are derated the 4CX5000A at 220 MHz, in that amplifier. I tried using the 4CX5000A in a 5 kW FM broadcast amplifier in the early 1980s and found it difficult, switched to 4CX3000A and then Eimac introduced the 4CX3500A, which was a natural at 108 MHz. 
I got the first tube for eval. from George Badger, and our product was introduced at NAB. Later, tetrode transmitter competitor still using the 5000A switched to the 3500A after we proved it could handle the power and the cathode was enough. 
It had similar base but lower internal inductance than 5000A, I believe. I never touched a 4CX5000A again. 

73
John 
K5PRO


> That reminds me, I have a couple of 4CX5000A 
> 220 MHZ amplifiers in the garage.
>   They are large and the power supplys extremely heavy.
> 73
> Bill wa4lav