[Towertalk] 160 Meter Sloper

Tom Rauch W8JI@contesting.com
Sat, 20 Jul 2002 22:20:17 -0400


> Can I attach the ground side of the coax to wire and run it back down
> the tower, grounding it at the bottom of the tower? This will allow me
> to put up the sloper without climbing the tower. (Tower is 120 feet
> tall with a tribander and 2 element stacked on top.) It seems like
> this would be about the same thing as using the tower as the ground.


That probably won't work correctly Bill.

Think of it this way...the wire coming down to the ground is part of 
the antenna. If it is 1/8 wl long, the impedance will be very 
reactive and different than the ground impedance. It actually acts a 
bit like a transmission line that radiates.

Sloppers depend on the tower to have a low impedance and minimal 
reactance at the point where the slopper is attached to the tower. 
That means certain combinations of tower height and antennas mounted 
on the tower will NOT work, and others will. Much of this is luck.

You'd probably be better off to put in a ground system and pull up a 
conventional Inverted L antenna or a bottom fed sloper, or even to 
install a Inverted Vee dipole.

  

.


73, Tom W8JI
W8JI@contesting.com