[TowerTalk] Network cable outdoors - more

[George Gorsline VE3YV]

Let me add to Pete's comments.  I use 2 CAT5 cables in parallel for the rotor cabling and use thicknet Ethernet cable (Belden 89880 orange jacket, triple shield, 50 ohm) for feedline, with a short piece of RG-213 for the rotor loop.  The cable specs are reasonable and price is usually right - free.  If it's used - pulled to put in fibre - there may be vampire tap breaks in the jacket to work around. UV resistance is unknown as the orange fades (not a bad thing - ugly and obvious), but have yet to see signs of water ingress from jacket deterioration, other than from improperly sealed coax connectors.  I do replace cables - Ethernet or RG-XXX - every 5-7 years whether they need it or not given the amount of acid rain we get.  Also I throw the analyzer on the feedlines to see if things "look different" an ohm meter on the rotor lines before an annual inspection to determine how much work may be needed.  Of course, YKMV (metric version)

Pete - can you post the URLs?
-- 

73,  George VE3YV / K8HI


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Message: 10
Date: Wed, 14 Nov 2007 07:31:28 -0500
From: Pete Smith <n4zr at contesting.com>
Subject: [TowerTalk] network cable outdoors
To: towertalk at contesting.com
Message-ID: <6.2.0.14.2.20071114071948.09cf4420 at mail.comcast.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

I just saw an item in the ARRL Contest Rate Sheet recommending a couple of 
URLs on this subject.  Both say that ordinary indoor network cable will 
deteriorate quickly outdoors.

That's probably true for fast data, but I have been using both 4-conductor 
indoor telephone cable and 8-conductor indoor CAT3 networking cable for 
connections between my shack and my tower some 200 feet away for the last 
7-8 years.  I control two TopTen 6-way relay boxes, an array of A/B 
selectors, and a homebrew 80m array switchbox through these cables.  I had 
to boost the shack-end voltage to about 14 volts to get reliable relay 
switching at the tower end, but in terms of reliability I'm quite 
satisfied.  The cables are simply laid on the ground in brushy woods, and 
the only reliability problems I have had result from squirrels or chipmunks 
chewing on the cables - and that has only happened once.  Of course, the 
cables fairly quickly become covered with leaves and grass, which no doubt 
helps with UV, but so long as the outer jacket remains intact, no problem.

Strangely enough, 14-3 UF-B "Romex", which I use for rotator power, has 
been far more of a problem.  One of my rotator cables has developed some 
leakage between the motor and indicator lines, causing some indicator 
errors when motor power is on.  Looking at the jacket, there has been some 
fairly serious deterioration from UV.  With the current price of copper, 
buying 1000 feet of 14-3 fills me with terror, but I may be approaching 
that time.

I just thought others might find this information useful.

73, Pete N4ZR
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