[Amps] Designing the Cleanest Linear with RF Negative Feedback

[Tom Cathey]

I called some ham friends looking for 4CX-350's drivers for the tetrode 
linear project.

One of the guys has some 8560A's, with sockets, heatsinks, etc. that I can 
swap some stuff for.  These are the conduction cooled version of the 4CX-250 
with 6.3VAC filaments.

I found the data sheets for it, but nothing is mentioned about the IMD 
figures.

Does anyone know what the IMD figures are for 8560A's or how this tube 
compares against the standard 4CX-350 for IMD?  These tubes were once 
popular in commercial quarter kilowatt FM rigs.

Thanks.
73,
Tom, K1JJ