Thread: Dish reflector
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Old April 21st 09, 10:02 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 Loading coils: was Dish reflector

Cecil Moore wrote:
Tom Donaly wrote:


No, it's not a diversion. You're making up things in your head.
The original controversy involved a claim by you that the coil in
a short, mobile antenna made up for the degrees lost in said
shortened antenna.


Sorry Tom, that is a false statement. Please stop misquoting
me.


I have the same recollection as Tom.

The loading coil occupies 19 degrees and the stinger
occupies 19 degrees. There is a 52 degree phase shift
at the coil to stinger junction. There are no "lost"
degrees. 19+52+19 = 90 degrees.

There were (are) two sides to the argument.

1. The coil furnishes the "lost" degrees.
FALSE!
The coil furnishes some number of degrees but not
nearly enough to make up for the phase shift at
the coil/stinger junction.


2. The coil supplies almost zero degrees.
FALSE!
The phase shift at the coil/stinger junction is not
enough to account for the "lost" degrees. The magnitude
of that phase shift is easily calculated on a Smith Chart.


Or, maybe

3. A less than quarter wave antenna is less than 90 degrees long.

ac6xg