[Elecraft] Ground Rods

[Fred Townsend]

Gary there are many factors effecting ground systems. In general concrete is
fairly conductive year round but earth conductivity is highly dependent on
the type of soil and its moisture content. Many a user of ground return
telephone systems found out clay soil in the summer could make you sound a
million miles away.

Grounding systems for the shack may need to fulfill multiple functions and
those functions are often at cross purposes.  The impedance of an
un-terminated transmission line inverts every quarter wave so connectors to
ground rods used in RF systems can be completely useless if they are more
than a fraction of a quarter wave in length. Likewise the vertical
connectors to earth grounds from 2nd floor shacks can become unwanted
radiating parts of your antenna system.
Such problems do not negate the effectiveness of such ground systems for
arresting lightning. Lightning does not like to make sharp turns so in
general the shortest, most direct path to earth ground, will be the best
lightning ground and the further away from your shack the better. 
This suggests that combination of a RF ground and lightning protection
grounds is really a series or combination of grounds. Quantity prevails over
quality. Fortunately I live in California where lightning is the exception
rather than the rule so I design a good RF ground and let it go at that. 

73
Fred, AE6QL


-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Gary Gregory
Sent: Monday, September 10, 2012 3:31 PM
To: Elecraft
Subject: [Elecraft] Ground Rods

*Interesting discussion locally here in VK.

Is there any advantage in having the Copper ground rod surrounded by
concrete over having the rod driven 6 feet straight into the earth?

Hope this doesn't get too far off topic or develop into a prolonged
discussion but I realised I didn't know the answer if there is one.

73
*
--
*Gary*
*Start the day off slow, then taper off.........*
K3 #679
KPA500FT #18
KAT500FT 007
P3 #1629
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html