[IRCA] "Detuning skirts"

[Charles A Taylor <MWDXer@xxxxxxx>]

Bill

Thank you for throwing me easy questions. Please, no existential questions 
like. "Why does a dog?"
"How many 6L6s are there in the Universe?" or "how many angels can dance on 
a surface-mount, 1-k
ohm resistor."

A detuning skirt is placed on a tower to make it non-resonant at the 
operating frequency of a station.
If the resonant frequency of a tower is near or at the operating frequency 
of a station operating
nearby or co-located, it will extract a significant portion of the radiated 
signal and re-radiate
it in a manner to directionalize or malform a directional pattern of that 
station.

Sometimes stations will erect towers that are nearly resonant at the 
station frequency, and that are
not tied into the station RF system. Such towers are called "parasitic 
elements" If too short to be
exactly resonant, they can act to direct a signal's radiated signal in 
their direction; if too long,
away from their direction. These are call "directors" and "reflectors," 
respectively.

A detuning circuit (not necessarily a "skirt") may sometimes be placed on 
water towers, TV towers, or
power transmission line towers that are located near a broadcast station's 
tower so as to prevent such
towers from malforming directional patterns, or directionalizing 
non-directional stations.

I'm sending this out on ABDX and IRCA because it may be of interest some 
others.

Seb'nty Threes,

Charles


   Charles A Taylor, WD4INP
  Greenville, North Carolina 


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