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RE: antenna rig and Lightning

> X-To:          amsat-bb@AMSAT.Org
> Reply-to:      <denniswj@hunterlink.net.au>
> From:          "Dennis James" <denniswj@hunterlink.net.au>
> To:            "saber electronics" <saber@vicksburg.com>, <amsat-bb@AMSAT.Org>
> Subject:       RE: [amsat-bb] antenna rig and Lightning
> Date:          Thu, 27 May 1999 10:40:29 +1000

> I have experienced a lightning strike on my antenna's and in my house, where
> it completely damaged my radio gear, even finding its way to the fax machine
> and video player.
> I agree with Phil on disconnecting all from antenna's and outlets.
> Get into the habit of disconnecting all antenna's and equipment from power
> outlets( when not in use ), also your line to the telephone modem. Even when
> there is no storms about as it's very easy to forget.
> Dennis De VK2DOR

May I recommend another solution...  Like most of us with multiple radios and
antennas, I don't (and most likely never will) disconnect all of my radio antennas
during a storm.  If I did that liveing in Iowa, I'd wear the coax connectors out :-)!

Its been my experince that most damaging voltage spikes come in through the
power line and telephone lines.  I suspect that the telephone is the worst offender.
My entire station including the computers is connected to power through a 
single bladed disconnect switch (fused).  This is simple old fashioned safety.
Remember the old ARRL "Switch to Safety" ads?

When the storms come up, I pull the switch and shut down the main bench.
If you want more "automatic" protection, run your modem phone line through a
DPDT relay with the relay coil activated by the 120VAC power.  Shutting the power
off automatically disconnects the modem line, simple!

You can also run your feedlines through PolyPhaser surge suppressors to protect
the antenna connections.  These are used on every commercial installation I have
seen in my area.  Heavy braided ground connections and good ground rods will
complete the installation.  

Interestingly enought the local two meter repeater (with three antennas connected,
UHF links, etc) stays on and connected through every storm.  It has never suffered
any damage.  I keep expecting it, but it has not happened in 12 years.  It sits in my
shack ten feet from my operating bench.  I must be lucky (or the 
repeater is)!

--73-- David WA0AUQ

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