Steve Lawrence wrote:
> I have an old Drake 1KW LPF in line running 1500w output from an Alpha 87A
> to a TH7DX. It's worked fine for several years. I've pulled the LPF out of
> the line. At 28000 with 1500W out, the reflected power dropped from 200 to
> 100 watts. There is also an improvement on 20 and 15.
> Comments appreciated.
The extra 100 watts of reflected power could be harmonic energy above the filter
cutoff. In other words, the filter is doing its job. Or some components have
changed value and the filter's characteristic impedance isn't 50 ohms any more.