I am having a little trouble with lightning and moose spoiling my beverages
and would appreciate some help!
My beverages are several thousand feet from the shack, and have two 'nodes'
each with a switch box. Power (24V DC) is fed down the hardline feeding the
antennas, and switching information is sent over a separate four core
amoured cable. Both cables follow more or less the same route and are more
or less the same length. The cable armouring is connected to ground/0V/coax
outer at each box. Each switch box contains a 4-16 line decoder and relays
to select the correct antenna. The logic is HCmos, and each logic input is
protected by a series 2k2 resistor, a parallel 100n capacitor, then another
1K resistor and a parallel 47K resistor and 4V7 surge suppressor actually at
the gate. Until I put this amount of protection in lightning regularly blew
the logic gates. Now it blows the input resistors! After the last event
(which prevented me hearing the 3B6 until Saturday) I have put relays in
series which ground the inputs and isolate the line when there is no 24V
present. I strongly suspect that these will have welded contacts in the
fullness of time. Note that I am not talking of direct strikes, but merely a
fairly local lightning storm. Any suggestions?
The further switch box is mounted on a tree about 1m above ground and the
final 30cm of cable is coax from a junction box where the hardline
terminates. Some significant animal, probably a moose, thinks coax is edible
and wrenches it out of the box occasionally. I have painted the coax black
and put oil on it to no avail. I have had no problems from gnawing critters
since I put in the hardline and armoured signal cable. Surprisingly, I have
had very little damage to the actual beverage wires running through the
trees except when trees have fallen on them. Any thoughts on moose
deterents?!?
Any comments would be appreciated, on the reflector, direct, or in person at
Dayton. I look forward to meeting the gang there again.
73 Roger
VE3ZI
ps I don't think it would have helped me if I had been able to hear the 3B6!
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