Mark,
I would strongly recommend not locating the relay at the 80ft level on your
tower unless you enjoy climbing, on a cold winter night, during a contest
or other inopportune time. Because that is when the relay will fail.
Locate it at ground level where it is easily accessible. Been their and done
that
Norm W4QN
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Message: 3
Date: Tue, 17 Aug 2010 19:40:13 -0400
From: "Mark Robinson" _markrob@mindspring.com_
(mailto:markrob@mindspring.com)
I am intending to fit this relay box at the 80 foot level on my tower
_http://www.arraysolutions.com/Products/dualfeed.htm#top%20of%20page_
(http://www.arraysolutions.com/Products/dualfeed.htm#top%20of%20page)
I planned on using wire like this to feed 12V to the relay
http://www.lowes.com/pd_314364-20424-55269-S4-08_4294821905_4294937087?produ
ctId=3128549&pl=1¤tURL=/pl_Electrical%2BWire%2Band%2BCable_4294821905_
4294937087_?cm_cr=Electrical-_-Web%20Activity-_-Electrical_A1_Activity-_-SC_
Electrical_Area1-_-19604_1
since it was readily available and cheap. I know that I don't need wire
this
thick but it is cheap. I plan on using a cheap Radio Shack 12V psu in the
shack. I don't want this cable tied into my expensive Astron 12V supply
which could be damaged by lightning and then feed the pulse into any other
equipment tied to the shack 12V DC bus.
I am planning on protecting the 12V line with "MOV Metal Oxide Varistor
24Z50 Harris 100J" on each line to ground at the base of the tower and at
my
SPG box. Adding some inductance just before the entry to the house might
help too. I started thinking about this and was figuring that it might
help
to ground the 12V return wire to the tower at the top and bottom of the
tower and at the SPG box. I wouldn't need MOV's on that return line then.
I
am not sure if this will provide any benefit from lightning. Taking this
thought a bit furrther, maybe I could run the power down the tower using
some old coax. The center conductor would carry the 12V positive and the
return would be on the shield which would be grounded at the top and
bottom
of the tower and at the SPG box. Will using coax in this way provide any
benefit over the wire from Lowes
thanks Mark N1UK
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