[TenTec] Grounding issues.

[WILLIAM F MANSEY]

I have read various comments concerning grounds, or the lack thereof, and am
no longer quite as sure about my grounding system.  I read, with interest,
the comment about the NEC grounding of antenna structure(s) to the AC mains
ground.  I recall, however, another comment that recommended that the
electric service be grounded at a single point ONLY. (generally at the area
of the connection to the utility lines)
I have a 40' push-up pole supporting my inverted V antenna and GP-9 VHF/UHF
antenna.  This pole is attached to a good ground rod directly.  I use heavy
braided ground strap from this point to the shack. (about 8')  The coaxial
cables for the antennas on the pole, and some others as well, come into the
shack via "bulkhead" connectors mounted on a 1/4" thick copper plate that is
connected to the ground strap also.  I can disconnect the rigs from the
bulkhead connectors, and plug ground jumpers into the connectors, during
thunderstorms.  The antenna tuners and rigs are all grounded to this
arrangement using pieces of the same grounding braid.  All my equipment is
operated from power supplies that do not ground (to the power line) the
negative DC lead.  I feel safe from lightning when the antennas are
disconnected and grounded.  Unplugging the power supplies is an added safety
measure.  The only danger remaining would be if the push-up pole was hit
directly.  (ground or no ground!)
I am concerned about setting up "The Mother Of All Ground Loops" if I
connected "my" grounding system to the AC mains ground.  Another concern is
due to the nature of my home's construction.  The house was built in a way
similar to concrete swimming pools:  A heavy frame of "rebar" covered by a
heavy wire mesh which then has concrete sprayed on.  This framework is
grounded to the AC mains ground.  This may sound like, and does act like, a
Faraday Cage! (windows spoil the effect) but the main purpose was resistance
to hurricane force winds rather than RF turbulence!.  The structure is rated
to withstand 200+ MPH winds.  I do not think that I would have any antennas
left after such winds but at least I should still have my shack! - and the
rest of the house as well.  Having said way too much - - - I am wondering
what IS the correct answer?  Combined or separate, and isolated, grounds?
(this is a Ten-Tec issue because 2 of the rigs are those!)
Any and all comment(s) appreciated.  True - this is not a real Ten-Tec issue
BUT it IS a matter of personal safety which I feel should be discussed until
a measure of agreement is reached.  We are heading into thunderstorm
season -especially here in Florida - so this is a timely discussion as well.
( a local repeater was hit 3 times in a year and a half.  2 of the strikes
were within 2 weeks of each other)  OUCH!


--
FAQ on WWW:               http://www.contesting.com/FAQ/tentec
Submissions:              tentec@contesting.com
Administrative requests:  tentec-REQUEST@contesting.com
Problems:                 owner-tentec@contesting.com