You are right, Guy, but I have plenty of test gear to check coax. I can sweep
it for return loss, check insertion loss and all that stuff. I use several HP
scalar analyzers as well as an 8753D vector network analyzer good to six GHz. I
have an Anritsu Sitemaster that has a great TDR function as well. I even have a
500 MHz 50 : 75 ohm transformer. Being a VHF and microwave addict, I am
constantly testing cables on the higher bands looking for humidity getting into
otherwise new good looking cable and making things NG. Checking cables for 160
is a piece of cake by comparison. I am running the new 1000 ft run of flooded
cable in conduit to my EU beverage , but I have also rejuvenated the chewed up
cable and its' insertion loss and VSWR are back to normal. TDR wise, I saw the
biggest bump at the BNC connector I put on one end. All the splices look pretty
good. I replaced about 15 ft of bad cable with F splices, dielectric grease,
and adhesive backed heat shrink tubing over each
splice. The coax was Belden flooded direct burial RG-6, and it appears that
water did not move very far in the cable. I'll use the repaired cable for
another beverage. There is room in the conduit for a second run of cable.
73
Dave K1WHS
----- Original Message -----
From: Guy Olinger K2AV
To: Dave Olean ; TopBand List
Sent: Wednesday, November 11, 2015 5:49 PM
Subject: Re: Topband: Why do rodents eat coax?
Gotta vote loudly with Frank on this one.
I had to throw away 480 feet of balanced "window" line (Wireman 554) that ran
elevated from my tractor shed to the base of my 3/8 wl 160 inverted L over FCP.
The spans were supported from trees a few inches away from the trunks. Very
easy access to squirrels as it turned out. They knawed the PE insulation off
the wires enough that water seeped the entire length of the seven copperweld
strand conductors on both sides. Forever ruined for transmission purposes.
Junk.
It slowly robbed me increasing ultimately to 3.8 dB extra loss. No sudden
change in performance to sound the critter alarm.
Dim view from here of reusing that knawed RG6. To put it bluntly if you can't
scan it for loss and impedance anomalies, chuck it and save yourself a lot of
trouble.
73, Guy K2AV
On Wednesday, November 11, 2015, Dave Olean <k1whs@metrocast.net> wrote:
Thanks to all who responded with all sorts of great hints and ideas for
combating the rodent problem with beverage feedlines. I ended up going with
buying 1000 ft of 1/2" PVC conduit and will lay that on the ground through the
woods. I ordered a new 1000 ft roll of RG-6 flooded cable to use inside the
PVC. I also removed my existing 1000 ft run of coax and gave it a good
inspection looking for chew marks. After laying the coax out in my open field,
I identified five areas where the critters had chewed it. At least three of the
spots were severe with chewing marks that went deep down to expose the center
conductor. I can cut the bad parts out and will only lose about 10-12 ft of
overall length. I'll put F fittings and splices there and will try to reuse the
old cable as well. It won't fit inside the PVC along with the new cable, but
hopefully, I can bury it enough so that it lasts a few years. I was hoping to
add another beverage at the same spot with a second feedline. I
can
lay out an 800-900 ft wire aimed at Africa and the middle East. That is
an area that I have had nothing in the past, so maybe I can improve things
while I repair the rodent damage. Those darn critters sure caused a lot of
damage and expense!
Anyway, thanks to all who responded. I appreciate all the great
comments and ideas.
73
Dave K1WHS
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