View Single Post
  #5   Report Post  
Old April 9th 07, 08:42 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default high earth resistance

On Sun, 08 Apr 2007 20:20:36 -0700, dansawyeror
wrote:

To focus on the question is: Why is the ground resistance so high?


Hi Dan,

Focus on Why? Why? This is something that you have absolutely no
control over without a huge investment in new dirt several 10s of
meter deep out to at least as far as the antenna is tall.

You want less resistance? then dig a hole and fill it with quartz
sand. Build a dune to drive the loss down further.

A suitable substitute is to lay out a ground field (radial wires). The
more the better. Here is the Why? you should be asking (Why more
wires?).

The path through the earth is shortened between adjacent ground wires.
Less path, less loss. The earth current travels not IN toward the
center as the radials do. The earth current travels ACROSS or
circumferentially towards the radial wires. This is due to the phase
lag between the induced earth current and the radial current. The
greater the distance between radials, the more path loss from the
average distance between the radials, to the radials.

As this is very difficult to treat in words alone, it is undoubtedly
confusing in the description above.

73's
Richard Clark, KB7QHC