Physically short stubs, was: QFH Antenna and 72ohm TV Coax
 

On Tue, 15 Aug 2006 13:57:12 GMT, Cecil Moore
wrote:


X=-j600*cot(130.2)=j507.7

507.7? Says who?

Me and two of my friends, Mr Hewlett and Mr Packard.

Thanks very much, Owen. I used the Smith chart to get 85, 130,
and 500 above. That's about as good an accuracy as I ever need.
Also MicroSmith says the impedance value is j507.2 ohms.

I am surprised that Microsmith has accumulated so much error (~0.1%)
after so few operations.

Owen
--

Physically short stubs, was: QFH Antenna and 72ohm TV Coax
 

wrote:
Cecil Moore wrote:
W8JI has theorized an even larger phase shift there at the
junction of a loading coil and the stinger of a mobile antenna.
Unfortunately, he attributes 100% of the phase shift below
the stinger to that single junction point, while ignoring
the phase shift provided by the loading coil. This thread
is my attempt at setting the technical record straight and
correcting W8JI's new old wives' tale. This discussion
started years ago on QRZ.com where both sides were wrong
and nobody was 100% technically correct, including myself.

There is nothing that verifies Cecil's theory except Cecil's theory.

There are a number of things that verify the laws of
physics. There is nothing that verifies your bogus 3 nS
delay through a 100 uH coil. You should be happy that you
were half right. The delay through a loading coil is not
nearly as large as the other side asserted.
--
73, Cecil http://www.qsl.net/w5dxp