Thread: Vincent antenna
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Old December 15th 07, 08:23 PM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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First recorded activity by RadioBanter: Mar 2007
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Keith Dysart wrote:
Each of the different ways mentioned for obtaining -j567
will produce a different impedance if the frequency is
changed. They were all frequency dependant.


Moral: Change the frequency and then observe what one
is dealing with?

I suggest that there is no value in thinking about
the "phase shift" at the discontinuity (which depending
on the black box chosen might not be present), and
merely think about the results of connecting the
-j567 impedance to the 600 ohm line.


The refusal to think about the phase shift at the
discontinuity is what got this whole thread started.

All you have to do to observe the calculated phase
shift is to use the s-parameter equations. When you
have done that, please get back to us.

Cecil did not answer the question, so I will
pose it again. If knowing the phase shift at
the terminals of the black box is important,
and you can not know it without knowing the
internals of the box, given a black box of
unknown internals but told that its terminals
present -j567 at the frequency of interest,
would you refuse to calculate the length
of 600 ohm line needed to produce 0 ohms?


Or asking the question another way: Is there
really a Santa Claus and a God?

Let's see you prove that it is really -j567 ohms
without applying any signal at all. How's that
for a requirement?
--
73, Cecil http://www.w5dxp.com