-----Original Message-----
From: jeff millar <wa1hco@adelphia.net>
To: Steve Thompson <g8gsq@qsl.net>; amps@contesting.com
<amps@contesting.com>
To: <amps@contesting.com>
Date: 17 May 2002 02:48
Subject: Re: [Amps] Nonsense
>
>----- Original Message -----
>From: "Steve Thompson" <g8gsq@qsl.net>
>To: <amps@contesting.com>
>Sent: Thursday, May 16, 2002 3:49 PM
>Subject: Re: [Amps] Nonsense
>
>
>> On Thursday 16 May 2002 18:02, Maurizio Panicara wrote:
>> > Hi steve,
>> >
>> > there is no doubt that spurs or products of various type may be
>generated
>> > along a wide spectrum in the most strange or unpredictable ways, but no
>sub
>> > harmonic is existing in the strict sense, the term is not poor choice
is
>> > totally unproper.
>> > I would like to know, it intrigues me very much, how to produce a real
>> > (true) frequency division using analog linear circuits and a sine wave
>> > carrier.
>> In linear circuits, I expect it's not possible, but few circuits are
>without
>> non-linear aspects that become significant under some conditions. As best
>I
>> remember the article I read, the argument goes that if anything (even
>noise,
>> maybe) causes f/2 to appear in a circuit, then IMD between f/2 and f
>produces
>> 3f/2, then both f and 2f with 3f/2 produce f/2 and so on, so it can
become
>> stable and self sustaining if the circumstances are right. The same
>analysis
>> can apply to f/3 etc. It's very common to find it when doing load pull
>tests
>> on solid state PAs.
>
>Ahh. That's the best explanation I've heard for what causes
sub-harmonics.
>Thank you.
>
>Now where's the nonlinearity in the solid state PA's? from the nonlinear
>junction capacitance or the nonlinear ferrites?
In the devices, I think. The effect happens in VHF PAs without any ferrite
in them.
Steve
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