Doug,
I have a copper tri-band (144/220/440) J-Pole on top of my mast. I made it
using 1/2 in. hard drawn copper with regular water pipe "T" and "L" fittings
with a cap on top. I have it mounted to the top of the mast. I have a TH6DXX
and above that a 14 El 2M beam. The J-Pole is at the top about 5-6 ft above
the 2m Beam.
It has been in the air for 12 years at this QTH. It was up for 13 years at
my previous QTH. I am not aware of any damage to it. We have experienced
several damaging electrostatic burst over the years. I do not know if it has
sustained any direct hit , because I have not had any occasion to climb the
tower since I erected it about 12 years ago. However, SWR is still good and
solid on all three bands. My Drake UV-3 has not sustained any receiver
damage on either of the 3 bands. I run each coax to the bottom of the tower
and have a 6-8 turn Coax coil on each line before it goes into the equipment
box at the base of the tower. from there all the antenna coax and control
cables go underground in PVC pipe and come up in the wall behind my
operating desk. A distance of about 100 ft. The tower is about 48ft tall.
That puts the J-Pole base at about 60 ft.
* 73's Jim W5IFP *
>-----Original Message-----
>From: towertalk-bounces@contesting.com
>[mailto:towertalk-bounces@contesting.com]On Behalf Of Doug Rehman
>Sent: Tuesday, June 02, 2009 1:24 AM
>To: towertalk@contesting.com
>Subject: [TowerTalk] Radiating Lightning Rod
>
>
>Well my GP-15 vertical on the top of the tower looks like it
>took a hit. It
>still works, but the SWR is varies all over the place (used to be pretty
>flat across 2 meters). This is the third damaged/destroyed
>GP-15 in as many
>years. I give up...
>
>I'm thinking about building a copper J-pole to put on the top.
>Does anybody
>have one on top of their mast? I'm wondering how well they
>survive lightning
>strikes (better than fiberglass radomed antennas I'll bet...).
>
>Anybody ever try to use #4 copper ground wire as an electrode to weld
>copper- maybe not an entire seam, but maybe spot welds? (I've heard of
>stranger things being done- just wonder if anybody ever tried it.)
>
>Doug
>K4AC
>
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