The staff of THE 59(9) DX REPORT will be attending the Dayton Hamvention and
look forward to seeing many of the Deserving DXers for an eyeball.
Look for them at: WX9X QSL Booth
DX Forum (Saturday)
Contest Forum (Saturday)
Hospitality Suite 325 in Stouffers - Friday &
Contest Banquet at Stouffers (Saturday)
We hope to see many of our subscribers and supporters for a chat.
>From Alex van Hengel <email@example.com> Sat May 4 11:18:37 1996
From: Alex van Hengel <firstname.lastname@example.org> (Alex van Hengel)
Subject: Amp Supply Comp
Can anyone help me with the Address for Amp Supply Comp.
Special interest in Email addres, Telephone/fax numbers.
--... ...-- Alex van Hengel. PA3DMH. ( email@example.com )
Member of PI4COM, Contestgroup Oude Maas.
PI4COM Home Page: http//www.euronet.nl/users/norf/pi4com.html
>From firstname.lastname@example.org (Steve Miller) Sat May 4 09:05:46 1996
From: email@example.com (Steve Miller) (Steve Miller)
Subject: Elevated cable runs
> I believe the key is to bring it to physical (and
> electrical) ground first at the tower base before running it in.
> As a simplified example, if you have a 100 ft tower, and bring the cable
> down to 10 ft, then run it into the shack, you may retain 10% of the
> voltage of a lightning strike on the cable.
It's not that simple - if you look at a lightning strike in the frequency
domain, a 10 foot height presents a very high impedance to ground when
the wavelength is 40 feet (quarter wave transformer) or an odd
multiple thereof. Thus, for the frequency content of a lightning strike
which occurs at these wavelengths, cable potentials are nearly 100% of
the lightning strike voltage (across the tower). A direct strike, or even
a near strike can result in extremely high potentials on the cables.
> because the tower appears as an inductance to the quick pulse of a
> strike, and the cable at the 10 ft level appears as a "tap" 10% above
> ground potential of the tower/inductor.
This is an over-simplification. Even if it were a completely valid
approximation, I wouldn't want 10% of a lightning strike coupled to my
Also, inter-band interference may increase if you ever want to receive
while transmitting on a second rig. Current induced on above ground
cables may compromise receiver performances unless you have a very good
(low impedance) ground connection at the entrance to the shack.
Above ground cables are usually easier to implement and may perform
adequately, but buried cables would improve the situation and provide better
lightning protection assuming a suitable grounding scheme is implemented.
Steve Miller WD8IXE