> From: Rich Measures <measures@vc.net>
To: <amps@contesting.com>
> Date: Tue, 29 Jul 97 00:42:22 +0000
> >Can you explain exactly what you mean by 'coherent'
> a sine waveform
>
> >and 'non-coherent'
> >waveforms?
> A square wave would be an example of a non-coherent wave form.
Earlier you defined coherent as a waveform with the same period, and
indicated if the period changed the RF PA wouldn't amplify the
signal. A square wave can have a constant period, and it can be
coherent (or it can be incoherent).
> Push-push RF linear amplifiers are only capable of amplifying
> single-frequency sinewaves.
That's total nonsense. What about a two tone test, FM, AM, or SSB?
None of those are single frequency.
It is true resonant systems, with a bandwidth of less than several
times the fundamental frequency, are incapable of faithfully
reproducing a square wave. But that has nothing to do with the
fact the PA is single ended. The problem is one of frequency
response.
For example...in one medical application, single ended tubes were
used to amplify 100 KHz square waves. Today, push pull FET's are
used in that application.
73, Tom W8JI
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