All of my transmission lines are buried except for the single coaxial cable
that feeds my 6m long-boom Yagi. After 15 years, I have not experienced any
problem with varmints chewing on any of my buried cables, despite being
located in the dense North Florida jungle.
However, the aerial coax located along the boom of my 6m Yagi was attacked
and destroyed on two occasions several years ago. The first time, some
critter stripped away the BuryFlex outer sheath, foil and braided shield,
and center dielectric along a 10-foot section of the feedline. That left
only a skinny center conductor as a very poor transmission line. At the
time I supposed that it must have been the work of nesting squirrels (tree
rats), so I simply rebuilt the feedline harness for the upcoming Summer Es
skip season. After a few months the problem returned and the coax was found
stripped away again. I set aside radio operating for a while and began
watching my 6m tower for evidence of the guilty party. To my surprise, I
found the culprit to be medium sized woodpecker birds. Two or three birds
would hang upside down under the Yagi boom and very efficiently strip away
at the coax until the damage was done. I rebuilt the feedline harness
again, but this time I installed all of the coax on the Yagi inside of
protective grey PVC conduit. The conduit did increase the antenna wind
loading, but I have not lost a transmission line to birds since then.
YMMV.
Terry K4RX
****
W8JI wrote in part:
Squirrels and rats can be a problem, but mostly my cable chew issues have
been from raccoons. I used to trap them and deport them a few miles.
Now I just I bury my cables. Even a few inches of dirt is enough. Where they
come up out of ground, I sleeve them with cheap plastic sprinkler pipe.
You can splice out the bad areas, but you have to bury, sleeve, or fix
whatever is eating it.
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