[ARC5] Impedance of an end-fed short aerial/antenna

[Brooke Clarke]

Hi Leslie:

This web page and those it links to may answer your question.
http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/radimp.html

In general a length of wire that's shorter than 1/4 wavelength is a small value capacitor

Have Fun,

Brooke Clarke, N6GCE
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

Leslie Smith wrote:....
  Second, there are many pages on the web that will calculate the proper length for a resonant aerial. (hehe - no 
antennae here - we follow the "Brits" in how we use language). I'm interested in the load impedance of "off-resonant" 
end fed wires. So - for example if I have a 35 foot length of wire trailing out the back of an aircraft, what complex 
"Z" will that present to the 1625's in the PA at, say 3.550 MHz. What it the wire is 55 feet long? Anyway, in the past I 
found a page that made that calculation - not for an aircraft, but for an end fed random wire. The calclulation allowed 
for a good many parameters, eg the dia of the wire (1mm, 2.5mm etc), height of the wire above ground and even soil type. 
The calculation result gave the impdedance as resistive and reactive components. Having searched (googled) for about and 
hour or so - I can't find it. Any pointers, clever types? 73 de VK2-land Les