[TowerTalk] Model done for 4SQ supported by center tower

[Michael Tope]

----- Original Message -----
From: "Jim Lux" <jimlux at earthlink.net>
>
> Fair amount of current in the tower, 136+j168mA at the base. 101-j69.8 mA
> nearer the top, all the elements were fed with 1 Amp.
>
> So the tower actually increases the forward gain (by an insignificant
> amount), but screws up the F/B.
>
> You could probably adjust the phasing a bit to fix the F/B


You could also put a shunt arm (20 to 30 ft long) near the base
of the 175' tower and then adjust it for parallel resonance at the
operating frequency  of the 4 square using a variable capacitor
in series with the shunt arm. You can model this pretty easily in
NEC.

73 de Mike, W4EF.............................................