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[TenTec] "Tuning" antennas; baluns

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Subject: [TenTec] "Tuning" antennas; baluns
From: rrossi@btv.ibm.com (Ronald D Rossi)
Date: Fri, 26 Sep 1997 12:23:49 -0400
>>>Chester Alderman said:
> Your correct. Reflections from the ground will change the resonant frequency 
> >of the antenna wires, be it a dipole type antenna or a loop type antenna. 
> >LESSON: Always try to raise your antenna to the height that your going to 
> use >it, and then cut it to the resonant frequency that you want. If you 
> can't >reach the antenna, when it's at the height that you are going to 
> operate it, >you can cut the transmission line (either coax or open wire 
> line) to a half >wave length (or multiple half wave lengths), connect the 
> transmission line to >the antenna, and measure the resonant frequency of the 
> antenna, down at the >input to the transmission line. The reason you can do 
> this is because the >impedance seen at one end of a half wave length line 
> exactly repeats at the >other end.

I am really enjoying this thread. A bit of myth and legend sprinkled in with 
fact and theory. Refreshingly off topic =:-) Anyway...

Won't the REFLECTIONs from ground change the pattern of the antenna, while the 
capacitive COUPLING to ground will detune the antenna by acting as a linear 
load of sorts?

73 de KK1L ex N1PBT...ron (rrossi@btv.ibm.com) <><
Ron Rossi H/P SRAM Engineering -- IBM Microelectronics
QTH: Swanton, Vermont

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