On Tue, 30 Mar 1999 13:38:39 +0100 Peter Chadwick
<Peter_Chadwick@mitel.com> writes:
>
>steve says:
>
> >I've not modelled it, but I think the load on the output side
>of a
> >harmonic filter will have insignificant effect (a few dB in
>typ.
>30+) on
> >harmonic attenuation with most filter topologies.
>
>
>Depends on the filter and the actual load impedance at the frequency
>in
>question. You can lose as much as 20dB of attenuation - although the
>likelihood of that much is probably on a par with winning the lottery
>-
>unless it just happens to be a situation where Murphy works overtime.
I believe it was John Belrose who wrote in QST Technical Correspondence
several years ago. He measured and reported that the topology as used in
ham LP filters had a minimal effect on performance at to at least a 2:1
VSWR.
I would be concerned with high VSWR on 10/15M.
I'll bring in a ICE filter to work and play on the network analyzer with
various resistive loads.
73 Carl KM1H
>
>Peter G3RZP
>
>
>
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