[Towertalk] Lightning Protection...roof tripods this time

Tony Casciato, AI9X Tony Casciato, AI9X" <ai9x@arrl.net
Fri, 13 Dec 2002 11:35:15 -0600


I have been following the thread about Jason N8XE's roof tower, and
researching Polyphaser right along like everyone else.

I have a small two-element TH2 on a 5 foot roof tripod supported with two 5'
masts - one above and below the rotor. I also presently am WAY under
protected since I am using only one ground rod seperate from the AC Mains
ground. I have all the info collected and am going to be redoing things,
including ordering one or two ICE protectors, etc.

My question is...is it safe to run coax, rotor lines and maybe one of many
tripod ground leads along the roof and down next to the AC service
enterance? The house is a single-story ranch style and the
mains/cable/telephone enter on the east side. I currently am bringing in all
the ham stuff on the north side, about 20 feet away. I don't know if the NEC
code prohibits bringing anything nearby to the mains - so I could continue
how it is, and connect the two grounding points together with braid or #4 on
the outside of the house.

A summary of my plans (flame here if you need to...)
   1. Attach either braid or #4 wires to beam boom, upper mast, rotor, lower
mast, tripod - then run down the roof, over the gutters to a series of
ground rods extending from the house outward. (How close to the house is
safe for installing ground rods?)
   2. Install ICE protectors on each coax line and rotor control wires.
Place these in a metal box outside and ground to above.
   3. Run a braid or #4 wires about 20 feet or so between house and deck
slab/driveway to utility grounding point.
   4. Shack is located next to utility panel in basement - attach SPG from
equipment to inside breaker box for good grounding. (I won't get a ground
loop since the rig attaches to the AC ground and the coax shield is
somewhere else, will I?)
   5. If needed, run another seperate ground lead from one of the three
tripod legs to another grounding "run" on the ground in the other direction,
and attach to the utility ground.

 I appreciate all the research/hard-work/advice that the tower owners have -
and someday I will have one or more (next QTH) myself. For a small TH2 beam
at 26', is this enough protection - or too much? I think that most tripod TV
antennas don't have near this much planning...but its my house!!

Thanks for reading this...enjoy the list very much.

73,
Tony, AI9X