Towertalk
[Top] [All Lists]

[TowerTalk] Suboptimum grounding/lightning

To: <towertalk@contesting.com>
Subject: [TowerTalk] Suboptimum grounding/lightning
From: davidw@copper.net (David J. Windisch)
Date: Mon, 25 Feb 2002 06:45:44 -0500
Hi, Todd:

When you're up in the air, and want to use h-f, one easy-to-write/say
solution is to engineer the station so that it has odd quarter-waves of
conductors in two (preferably pi-radians apart) directions, at all
frequencies of interest.   This tactic puts the station at a low r-f
potential, while tending to suppress far-field radiation.

To accomplish this, I have a purposely-crummy (low-Q) trap dipole wound
around corners inside the house, which the cats occasionally find ;o))), the
center of which is connected to the pipe running across the back of the
operating desk, to which all station equipment is connected.   IMO, this is
one of the few legitimate uses of traps.   The station is connected to the
00 cable mentioned below.

If I split the dipole and feed it, it radiates -- poorly, which is the
intent.

Since it's just me, the cats, and the Rotts, I can do all sorts of things
over which could make the women and the neighbors suicidally-despondent.
Heh-heh.

Come spring and hamfests, I'm going to get another dipole, maybe wire, maybe
tubing with commercial traps, and mount it a few inches off the house wall
outside, a foot or two off ground, so it's easier to experiment on.   Got
plentya maybes I want to know more about.

As for lightning, you're on your own.   I have a number of 8-ft gnd rods,
connected by 00-size cable, and will put pointy things connected to the 00,
on the ridge-pole of the house B4 long.   Dunno what this will do, as
lightning is capricious, and I have a dozen 40-60-ft organic antenna
supports within a 40M dipole of the house.

HTH.   Lemme know.   Got plenty of hard-won experience, if you need more,
eg, I do a variation of this with FD installations, cuz I'm tired of burning
my upper lip on a metal mike, or my fingers or ears on hot keys and cans.

73, Dave, K3BHJ


________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes?  The
same place that pays for the hosting of this list:  The eHam Store.
Order online at http://store.eham.net.
-----------------------------------------------------------------------

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


<Prev in Thread] Current Thread [Next in Thread>