[TowerTalk] Holy SteppIR!

[Jim Lux]

At 09:20 AM 12/27/2005, StellarCAT wrote:
>huh?
>
>He can adjust the frequency but not the radiation angle. This is
>strictly a function of height above ground for the major lobe.
>Or are you saying he has a coax phasing line that is adjustable?
>That is the only thing that could change the relative phase of
>one antenna to another - changing the resonant frequency of theb
>elements only changes the gain and f/b.

Changing the resonant frequency changes the feedpoint impedance at the 
working frequency.  A fairly small change in the length of the element 
could easily change the radiated phase by 45 degrees (all you'd have to do 
is adjust to 50+50j ohms, for instance).  So, considering a two stack, if I 
adjusted the top to 50+50j, and the bottom to 50-50j, the two antennas will 
be radiating 90 degrees out of phase.

Nothing really different here from making some elements longer and shorter 
than the driven element to form a beam in a conventional Yagi.