View Full Version : Complexe resistanc of an endfed wire
Thadde
06-30-2012, 09:32 AM
Hallo everybody
I am interested to calculate the complexe resistance of an endfed wire antenna. The following is known:
-Length of the wire
-Diameter of the wire (mm)
-High above the ground
-Working frequency
Is there anybody who knows to calculate it with the necessary formulas?
Thanks in advance with mni 73 de Thadde HB9DNB Switzerland
Radio
06-30-2012, 10:32 AM
:welcome:
Welcome to Open Roads Radio.net.
Do you mean the impedance (Z) of the antenna?
There's some pretty smart folks on here, I bet someone will get you an answer. I have plans today but finding that answer in one of my books sounds like a project for tomorrow.
OK, all you engineers - what's the formula?
W9WLS
06-30-2012, 11:55 AM
You might take a look at,
http://www.cebik.com/content/index.htm
W9WLS
06-30-2012, 12:54 PM
OR down load this Article (pdf) .
http://www.kc7hxc.us/links/radio/hf/Long-Wire%20Notes/longwire-kc7hxc.pdf
OR
http://www.smeter.net/antennas/end-fed-matching.php
OR
http://www.laarrl.org/pdfs/upthecoax10.pdf
W9WLS
07-01-2012, 06:37 AM
Let me add two more sites to the list.
http://www.aa5tb.com/efha.html
AND
http://www.njqrp.org/n2cxantennas/halfer/index.html
As you most likely know, impedance whether simple or complex , is going to be relative to frequency, if you are concerned with a single band it should be fairly simple , but the more harmonically related bands you try for the more complex things become, an antenna analyzer IS the best tool to use here, a "GRID DIP METER" would be the next best .
Good Luck & 73, John
Radio
07-01-2012, 11:40 AM
Hey Thadde,
Give us the numbers to plug into the formula. That should be more fun!! :think:
wa8yxm
07-01-2012, 03:41 PM
If you buy the ARRL antenna book, the program you need is on a CD taped to the inside cover (Back I think).
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