Topband: topband post - waller flag antenna

[n4is]

Hi Chuck

 

The detuning cap is used on my TX antenna, the tower has a skirt and it
works like a ¼ wave stub, short circuited on the top and high impedance at
the base of the tower. When the TX tower is detuned there is no reradiation
or interaction between with the RX antenna. This kind of vertical is called
UNIPOLE VERTICAL or FOLDED UNIPOLE

 

The value of the capacitor was found measuring the resonant frequency of the
Skirt and brings it to 1830 KHz.

 

 

Here some useful links about detuning antennas and UNIPOLE

 

www.amcoordination.com/Foled%20Unipoles.htm

 

http://radiomagonline.com/mag/radio_useful_folded_unipole/index.html

 

http://www.ncjweb.com/novdec05feat.pdf

 

 

 

Regards

Carlos

N4IS

 

 

 

  _____  

From: Chuck Hutton [mailto:charlesh3 at msn.com] 
Sent: Saturday, July 14, 2007 9:26 PM
To: 'n4is'
Subject: topband post - waller flag antenna

 

Hi Carlos – 

 

I went to your web page (http://taliaphoto.com/n4is/BIG_DUAL_LOOP.html) and
see many patterns are labeled with the value for the “det cap” (detuning??).
I don’t see this cap in any of the drawings on that page and wonder where
they are and how you chose the values.

 

 

73,

 

Chuck

WD4ELO