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Old June 10th 04, 02:19 PM
Dale Parfitt
 
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"Cecil Moore" wrote in message
...
JGBOYLES wrote:
Hi Hank, A 1/2 wave shorted stub looks like a series resonant circuit.

It
makes a good notch filter, which is one of the Amateur applications that

I have
used. You are right, they don't dissipate any power since Power=I**2*R

and R
equals zero.


Stubs dissipate the maximum amount of power possible since the SWR on a
stub is nearly infinite. If you don't believe it, hang a Bird Wattmeter
halfway down a stub. The ratio of Vmax/Vmin and Imax/Imin is very high.
If the stub were lossless, the SWR inside a stub would be infinite.
After all, a stub is merely a shorted or open piece of transmission line.
--
73, Cecil http://www.qsl.net/w5dxp

I would have to agree Cecil. The point is proven by the fairly shallow notch
afforded by a single stub ( approx -20dB at VHF). I can do better with a
quality L-C combination.

Dale W4OP