[AMPS] parasitics

[amps@txrx.demon.co.uk (Steve Thompson)]

In message <F2B87FD6828AD11196F100A0C9410EC2617D73@excalibur.swindon.msl
.mitel.com>, Peter Chadwick <Peter_Chadwick@mitel.com> writes
>
>2. just because there's a VHF resonance doesn't mean that there will be a
>parasitic oscillation. There has to be feedback and gain.
>

And, if there's a parasitic oscillation, it doesn't mean there is a
resonance (or that the oscillation is occurring at any resonant
frequency if there is one).

All it needs is the load on the active device to have the necessary
magnitude and phase (resistive and reactive components). It's more
likely to happen at a resonant frequency because the phase spins around
a lot and you are more likely to hit the angle for oscillation.

Steve

PS talking of puns, I think someone mentioned the 'grate' parasitic
debate - perhaps a reference to how it seems to grate on some people?

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm