I am involved with a ham radio club that has repeaters on the top of a 55-story
condo building 6 miles north of downtown Chicago on the Lake Michigan
lakefront. The club is a general purpose ham club, not a repeater club, and
does not seem to have any members who are in the 2-way radio business or have
experience with commercial repeater site installations.
They've had a 70cm FM repeater on this building for about 15 years. It has
never had any form of lightning protection equipment protection equipment. The
club has been lucky and not experienced any apparent problems from lightning..
Within the last two years the club has replaced it's Icom 70cm FM repeater with
a new commercial Motorola 70cm FM repeater. They've also added a D-STAR 70cm
Digital Voice repeater, a D-STAR 23cm Digital Voice repeater and a D-STAR 23cm
Digital Data Access Point. It's possible a 23cm FM repeater will also be added
soon.
There are three antennas on the roof currently for 70cm FM, 70cm D-STAR and
23cm D-STAR. A fouth antenna may be aded for 23cm FM. All antennas are fed with
hardline & ultimately terminated in N connectors at the repeaters.
It is a very ham friendly site and we can do work on the repeaters & the roof
unsupervised. The only other repeater system on the building is a high-band
U.S. government repeater adjacent to the ham repeater equipment rack. The
government repeater seems to be grounded to a grounding bar running through the
equipment room.
These new repeaters & antennas should have lightning protection. My question to
the group is what form of lighning protection would you recommend for these
repeaters. I assume Polyphaser equipment is one option, but we need
recommendations of specific brands & model #s of equipment with approximate
prices if you have them. We plan to review any recommendations received & then
forward them to the club's board of directors for acquisition & installation.
Please reply to me directly and thanks in advance for any advice you have.
73, Mark, WB9QZB
Chicago, IL
