[Amps] Bandwidth tests

[Tom W8JI]

> White noise is definitely worst-case, and with max allowed 
> ALC it makes an ugly spectral plot.

That's not true at all!

Steady white noise is NOT a good test of dynamics of bias or 
ALC systems. As a matter of fact, it is the poorest test 
available for determining bandwidth problems related to poor 
power supply dynamics, poor ALC dynamics, and other similar 
problems.

ALC testing requires a three-tone or pulsed two-tone or 
noise test at various pulse repetition rates. Amplifier IM 
products related to typical screen or bias system dynamic 
regulation shortfalls NEVER show in a steady white noise 
test.

If I wanted to use a test that masks bad power supply 
dynamics or ALC attack problems and make the system look 
significantly better than it does on voice, it would be a 
white noise test.

73 Tom