> ----- Original Message -----
> From: Vic Rosenthal <rakefet@rakefet.com>
> To: Steve Lawrence <smlx@earthlink.net>
> Cc: <amps@contesting.com>
> Sent: 16 November 2002 17:11
> Subject: Re: [Amps] LP filter effects
>
>
> > 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.
>
> If we are looking at 100W of harmonic energy in 1500W output power, that's
> only 12dB down. I'd expect the amp to be a lot cleaner than that.
>
Amen, Steve
- Rich..., 805.386.3734, www.vcnet.com/measures.
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