Don Wilhelm wrote:
Folks,
There is an error in the reply I sent last night (below) that is very
important - it makes a big difference.
When increasing or decreasing the frequency to determine the sign of the
reactance:
One must observe the increasing or decreasing of the IMPEDANCE (Z) and not
just the reactance.
You can note in Larry's VNA data that |Z| has four inflection points and
that phase = 0 at each inflection point.
i.e., if d|z|/df = 0
where f is frequency and the d symbols refer to differentiation
there must be a phase zero, which can be seen to be true, since only an
impedance with a net zero reactive component will have no change in
impedance with frequency.
This is one of the three definitions of parallel resonance. The
interested reader can find the other two definitions in Terman's Radio
Engineer's Handbook, amongst other places.
Jack
www.cliftonlaboratories.com
_______________________________________________
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com