[Amps] Tuned Input - IMD and efficiency

[Tom W8JI]

> this forum. I've not found any conclusive data although I 
> believe a tuned
> input does decrease IMD products to a degree. I'd like to 
> know how much
> improvement can be expected in different scenarios with 
> the use of tuned
> input.

Based on how the system works (as shown in changes in 
efficiency) it would depend on the exciter, cable lengths, 
and the impedance presented at the cathode.

There can be cases where it doesn't change, where it gets 
worse, or where it gets better depending on what the tube 
and exciter see and how the tube and exciter react to the 
harmonic levels and frequency in waveforms.

Anything meaningful won't be a simple test since different 
systems will react differently. Multiple systems would have 
to be tested.

73 Tom