[SECC] ARRL 160 - KU8E

[Bill Coleman]

On Dec 5, 2005, at 12:09 AM, k4sb at bellsouth.net wrote:

> There is absolutely NO way a change in feed line length can affect the
> resonate frequency of ANY antenna.

Assuming the feedline is fully decoupled from the antenna, sure. If  
we put a current choke on that feedline right where it feeds the  
antenna, then your statement is true.

However, if return currents flow on the outside of the coax, the  
length of the coax may have some effect on the resonant point of the  
antenna.

That's why it's a bad deal. You don't want common-mode currents  
flowing on the feedline.

> Adding radials has absolutely no effect on the resonant frequency  
> of the
> antenna.

Although the theoretical impedance of any component doesn't change,  
the reduction of losses allow those reactive components to come more  
fully into play. Although theory talks about these losses being  
lumped, they are actually distributed.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901