Thread: Dish reflector
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Old April 17th 09, 09:27 PM posted to rec.radio.amateur.antenna
Jim Kelley Jim Kelley is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 666
Default Dish reflector

Cecil Moore wrote:
Jim Kelley wrote:
I understand it well enough to note that it fails to make your point
for you.


You obviously don't understand why a signal that doesn't
change phase cannot be used to measure a delay based
on phase shift either through a wire or a coil.

1. Every reference says a pure standing wave does not
change phase.


Certainly not as a function of time. Which means it's not an
alternating current, and which is why it not considered an actual wave.

2. The current on a 75m mobile antenna is at least 90%
standing wave current.


And what's the other 10% supposed to be? Please explain how one would
go about getting "standing wave current" to flow through something -
anything - like a measuring instrument for example.

3. Therefo The phase of the current on a 75m mobile
antenna cannot be used to measure the delay through
the loading coil or even through the straight wire
parts of the antenna.


Have you tried pulsing a current through one? I can't imagine there
wouldn't be a delay in getting from one end to the other and back.

4. Yet, this is exactly the current that w7el and w8ji
used in their measurements


No, it is not.

Here's a question for you: What is the phase shift
in the current in 90 degrees of an ideal lossless
1/4WL stub?


I'm reminded of the troll at the bridge.

To what phase shift do you refer? With respect to voltage, from one
point to another, out and back - you need to be considerably less
imprecise if you expect someone to bother to answer (to) you.

ac6xg