Do I need to ground attic antennas?
John Marx
I'm building a home on a rural hilltop. The location alone will make it
lightning prone. Antennas (mine are receive only for FM, TV and Public
Safety bands) will be generally restricted to the attic. Will their
location in the attic reduce their tendency to build a charge and attract
lightning? How important is it to ground them? If it is important,
should I just tap the coax or is a separate grounding wire needed?
Thanks for any advice.
Anthony Severdia
In <4o5chc$u...@musky.state.wi.us> ma...@doa.state.wi.us (John Marx)
writes:
If the location itself is "prone to lightning" as you say, you'd
best install an external (separate) lightning accumulator at a high
point and well grounded. The antennas in an attic would be least of
the problems!
-=Tony=-
mlu...@tamu.edu
In <4o5chc$u...@musky.state.wi.us>, ma...@doa.state.wi.us (John Marx) writes:
>I'm building a home on a rural hilltop. The location alone will make it
>lightning prone. Antennas (mine are receive only for FM, TV and Public
>Safety bands) will be generally restricted to the attic. Will their
>location in the attic reduce their tendency to build a charge and attract
>lightning? How important is it to ground them? If it is important,
>should I just tap the coax or is a separate grounding wire needed?
>
>Thanks for any advice.
If you are the natural target at a hilltop and are worried about this, put in
a formal lightning arrestor spike setup on the house. Phooyee on worrying
about the indoor receiving antennae. You have a LOT more to worry about
than that!
Mike W5WQN as a guest at leviathan.tamu.edu (no mail address there)
Jonathan Helis
When I was in school, I had an attic antenna for SWLing for nearly 5
years, and never had a problem. In another house I lived in for about
the same amount of time, I had another attic antenna, and again, no
problems there. The antenna was just a long wire that was connected to a
reciever, and when I got my ham ticket, to a tuner, and I never had a
lightening problem inside the house.
The only problem I had was when the roof was wet, such as after a rain,
the antenna wouldn't always load up on some bands like it normally did.
I attributed this to the water making the roof conductive. I don't know
if this is accurate, but it's as good a guess as any.
Also to be noted is that some roofing materials are conductive, and will
interfere with incoming and outgoing signals. In my experience,
listening in the rain was difficult anyway, mainly due to electrical
interference from lightening, and it's safter to unplug such appliances
in electrical storms anyway.
These are just my experiences, I didn't live on top of a hill at either
house(we don't have many hills in Southern Louisiana), so my advice may
not apply. Good luck!
73,
Jon Helis, KB5IAV
Graham Seale
In message <4o5chc$u...@musky.state.wi.us> John Marx wrote:
> I'm building a home on a rural hilltop. The location alone will make it
> lightning prone. Antennas (mine are receive only for FM, TV and Public
> Safety bands) will be generally restricted to the attic. Will their
> location in the attic reduce their tendency to build a charge and attract
> lightning? How important is it to ground them? If it is important,
> should I just tap the coax or is a separate grounding wire needed?
>
Hello John
Structures inside an attic will not "attract" lightning. Every single
lightning arrestor scheme I have ever seen involved *very* sharp points
mounted high outside, connected to a grounded strap, designed to cause a
local corona discharge to reduce the potential of the whole structure.
Presumably if a strike is imminent, it will go somewhere else. As
explained to me, if a strike should happen it will do its damage tracking
down the copper strap, lessening the risk of shock and fire in other parts
of the building.
Although (with cause!) I have had this lifelong lightning paranoia, and I
soak up all that is ever discovered about it, I have yet to find really
authoritative explanations and advice. The whole recipe for strike
avoidance schemes seems to add up to "lightning attractors". A sailing
friend once said to me..
"Plant a real *sharp* pole, then stay away from it, and you will be OK;
but plant a real *blunt* pole and lean up against it while under an
umbrella, then you are temptimg fate!" He also had a low opinion of those
who would continue to play golf despite smelling ozone around the little
flagpoles.
Perhaps this thread will produce some nice credible stuff about lightning.
73's G4WNT
-- Graham Seale