[TowerTalk] Trap Drain Holes

Dan Hearn n5ardxcc at gmail.com
Mon Apr 8 23:17:36 EDT 2013

The ideal antenna drain hole would have a reasonably large diameter but
would not allow insects to enter and build nests. I believe there is a way
to accomplish this.
  There is a material used in sanding pads which is springy and would allow
water to pass but not insects or debris. It is somewhat similar to steel
wool physically but is not electrically conductive as far as I can tell. I
have been using strips of it to wrap around wires into and out of metal
cabinets at the base of my towers to discourage Wasps from entering. It is
quite springy and I have noticed no deterioration over 5 or more years here
due to sun and weather conditions .
  If you have a coil in a PVC cover I would drill a hole possibly 1/2 inch
or so in diameter , cement a short piece of PVC tubing into it at the
bottom maybe an inch or so long and insert some of the springy sanding pad
material into it.
  None of my antennas have traps so I have not tried this. I plan to get
some of the stuff and check if it affects the inductance of a coil out of
  There are probably readers out there who know more about this material
than I do and I invite comments on this idea..
Dan, N5AR

Dan Hearn

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