Topband: Beverage grounds

[Steve Miller]

N6RK wrote:
> 
> when I used radials, I typically would have
> 3 or 4 quarter-wave radials on each band, 160, 80,
> and 40.  That is a bunch of wire!  I wouldn't
> expect seven 10' radials to do a whole lot on 160.


Rick et. al.,

I laid out a beverage on the ground (BOG) for ARRL 160.  
This was a temporary, lot-size limited, 160m only 
antenna located where driving ground rods more than 2
feet deep is very difficult.  As a result, the ground 
connection at the feed end used two inductively loaded, 
20-foot long radials oriented perpendicular to the BOG. 
The radials were tuned by feeding them like a loaded 
dipole on the ground (loaded DOG - a fitting acronym) 
and adjusting for resonance at 1830 kHz.  The DOG 
terminals were then shorted together to serve as the 
ground connection point for the matching XFMR.  

This arrangement provides low enough ground impedance 
to keep received signal levels from the ~300 ohm BOG 
within 1 or 2 dB of an ideal ground termination 
between 1800 and 1860 kHz. Quarter wave radials would 
improve performance but 88 foot long (~65% v.f.) 
radials are too big to fit on my lot.

Installing the BOG was well worth the effort and I'm 
looking forward to more BOG and loaded radial 
experimenting next fall.


73,
Steve  N8SM/5