[PVRCNC] Lightning damage?

alsopb [email protected]
Tue, 03 Sep 2002 15:11:25 +0000


About two weeks ago before the monsoon season was fully upon us, there
was a huge thunderstorm which seemed to sit on top of us.  Lots of
lightning.

Twice coincident with a large flash there were odd clicks emanating
from the shack.

The next morning I found out that the 160M antenna and all the
antennas attached to the outdoor switchbox at the 40M beam tower
didn't work.

OK mother nature got even for us probing her sky with lightning rods.

What really happened was somewhat of a surprise.  I didn't find
anything obviously fried anywhere.  
-----------------------------------
The 160M antenna measured out fine at its feedpoint.  Tracing back
yielded something wrong in a small piece of RG8x used for about 20'. 
Replacing it solved this problem.  However, I found nothing wrong with
the piece upon dissection....  

-----------------------
Bringing down the HAZER and opening the remote switchbox also yielded
a surprise.  It was in perfect shape.  The relays all operated
properly.  Putting it back and tightening all connectors "cured" the
problem.  Loose connectors?  All was fine with the HAZER half up. 
When the HAZER reached the top, the problem occured again. 
Measurements from the shack indicated the coax was open somewhere
about 330' from the shack. At least the LMR600 coax was good. Down
HAZER again.  Inspection of the connection of the LMR600 to RG213
rotor loop junction was suspect.  After taking off tons of electrical
tape, the problem was obvious.  The expensive LMR600 UHF connector
simply twisted off in my hand.  This connector uses an N-type
construction with the braid not soldered to the connector. Instead the
braid is pressed between a ferrule and the connector body.  I hate
them.  

Why it choose to fail after a storm is a mystery.  There was no force
pulling the coax out due to a bunch of tiewraps and tape.  Perhaps for
years it was just making connection by a few hairs of braid and these
were vaporized.  Who knows.

73 de Brian/K3KO 

PS-- I haven't even looked at the beverage antennas.  These get
routinely destroyed during the summer.  A rebuild is always necessary.