Robert11 wrote:
Hi,

Have an attic located, receiving only, random length antenna.

Thinking of stringing one outdoors, but have a few questions, and concerns,
regarding nearby lightning.

a. would you folks agree that having it indoors under the house roof,
probably provides 0.0 % added protection relative to if it was outdoors ?
That any additional indoor protection due to being indoors is probably more
psychological than anything else ?

b. We gets lots of lighning strikes around here. Happy to say that they
have all been "nearby".
This is the crux of what concerns me.

I can't help but feel that if there ever was a truly direct strike on the
wire running (horizontally) outdoors,
a gas discharge tube protector like the Alpha-Delta ones wouldn't really
help much.

But, for the nearby strikes, where possibly just a few hundred volts perhaps
is induced into the wire (but enough to fry the radios front end), would the
Alpha Delta types even trigger ?

c. what's the best protection for "nearby" strikes, other than a total
disconnect ?

BTW: would grounding of the wire be equally effective as a total disconnect
of it ?

Thanks,
Bob



Having your antenna indoors probably provides a little help against a
direct strike because odds are there'll be flashing or something else
that's metal above it. But I doubt it would be meaningful. I know
someone who had a direct strike at his house and besides the damage
you'd expect, he had a gaping hole in a corner of his basement - the
cement was turned to dust.

Near strikes can still cause a lot of damage.

I use an impedance matching transformer with a couple of ground rods out
by the antenna, and I use fat stranded wire to the ground rods.

The last near strike caused some of the antenna wire to melt, the
ferrite for the transformer vaporized, and bits of the abs plastic
outdoor electrical box it was in were found 15 feet from where it was
mounted.

The coax to the house, and my radio was fine - possibly because I use a
polyphaser between the transformer and the coax too.