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ANTENNAS ON EZs
(From CP35, Page 6, January, 1983)
From the desk of Jim Weir - Radio Systems Technology:
"NO ANTENNA FOIL ON THE GEAR LEGS. NONE, NO HOW, NO WAY. Get the idea? There have
been a series of reports that the gear-leg antennas work very well when first installed,
then gradually deteriorate over time. Actually, the "deterioration" seems most
pronounced after a hard landing. The copper foil is not as resilient as the glass, and
rather than flexing like the fiberglass, the copper tape breaks. Net result - lousy
antenna operation.
Instead of copper tape, use a copper braid similar to Radio Shack
642090 (use 2 strips side-by-side) or Belden 8664. Every bit as good, but slightly harder
to make, is to strip the black jacket from RG58 coaxial cable, remove the
polyethelyne/copper center conductors, and flatten out the resulting braid. Install this
on the gear leading edge or trailing edge, not at the maximum thickness, to avoid flex
failures.
For those of you who have a broken antenna, I recommend removing
as much foil as possible - - both elements of the dipole -- and glassing braid on the
OPPOSITE leg. It would be a major job to strip the glass from the broken glass and remove
it, so I suggest you just leave it alone.
Actually, if I was a-building the airplane, and I didnt
have the wing and winglet glassed yet, I'd go ahead with a winglet antenna like the
Long-EZ has for the COM antenna.
Jim Weir
On new construction VarlEzes the "Long-EZ" comm antenna
can be installed on the winglet and outboard wing as shown. Follow the instructions in CP
26, page 7 for the Long-Ez comm antenna.
Incidentally, Jim recently checked the performance of a Long-EZ
winglet COMM antenna and its radiation pattern proved to be quite exceptional, much
more uniform than the factory builts.
