[Elecraft] KPA-1500 failing on 160...AGAIN!

David Gilbert xdavid at cis-broadband.com
Fri Sep 27 17:45:55 EDT 2019


I've probably posted this here before, but I once had a 160m Inverted-V 
at 70 feet that didn't have a DC ground.  As a thunderstorm approached 
(but was still several miles away) I reached down to short the coax end 
in the shack and drew a heavy blue 2 inch long arc that traveled from 
the end of the coax into my left arm and out my right arm to the 
concrete floor.  My biceps were sore for three days.

The breakdown inception voltage of 2 inches of dry air is generally 
considered to be over 150,000 volts.

73,
Dave   AB7E



On 9/27/2019 1:59 PM, K8TE wrote:
> For those with insulated verticals, the potential gradient is about 100
> V/meter.  That varies with humidity and altitude.  But, you get the picture.
> In dry climates like here in NM, this is a big deal for commercial broadcast
> AM antennas.   Even with the transmitter shut down, unless there is a "DC
> ground" on the antenna, one shorts the tower to ground first prior to
> climbing on or off the tower.  This was a big deal when the local power
> company rescued three folks from our 770 tower after it "captured" their hot
> air balloon!
>
> Bleeding off static electricity is a big deal.  Wind blowing dust, snow, or
> rain can generate thousands of Volts that can provide a mean shock to us
> humans and hurt our radio gear.  I am leaving for the race track to play
> with my Miata this weekend.  I will disconnect my antennas, just in case.
>
> 73, Bill, K8TE
>



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