[Amps] analyser on output

[Tom W8JI]

> Are there any threads, cautions, general advice, web sites 
> to help with using an analyser on the output of an 
> amplifier?   I seek general enlightenment and a tool for 
> comparing one amplifier with another, ageing effects, 
> fault finding, searching for conditions that might support 
> parasitics and the like.
>
> I have a AEA VIA antenna analyzer and MFJ259.
>

The information gathered by using a 259 or any other antenna 
analyzer is very limited, but can be quite useful. For 
example you can check the input network for performance by 
terminating the pin of the amplifying device with a resistor 
or load that simulates the input impedance and looking into 
the input port of the PA. The same is true for the tank by 
looking back into the output port of a cold amplifier if the 
anode or device output pin is terminated in a proper load.

It's also possible to get a rough idea of choke performance 
at HF.

With some method of measuring signal levels you could use it 
as a signal source to test neutralization.

What are you trying to do?

73 Tom