Phil wrote: "A FLARM is a radio and needs the aerial positioned in a
good place to work correctly. This is tricky in a carbon glider. The
performance of FLARM varies widely depending on the
aerial. . . ." [snip]

For the benefit of those who may not know, a Flarm unit uses two
aerials. One is a GPS receiving aerial. If this is positioned so that
it receives GPS signals, the Flarm will record GPS positions and
produce a log, AIUI. This will be regardless of whether the other
aerial is present, and/or operative. The Flarm GPS aerial may,
however, need careful positioning to avoid interference with other GPS
units. The one that came with my (basic Swiss Flarm) unit is on a long
lead, and I was able to position it on the head rest, immediately
under the canopy where it gets good view of the sky. There is no
problem with this location in my carbon fibre (Lak 17A) glider.

The other aerial is for Flarm to Flarm communication. It is attached
to the top of my Flarm unit, though I believe a remote aerial and fly
lead is available if required. This is the one that seems more of a
problem in a carbon fibre glider, because if positioned on top of the
instrument panel as mine is, it can fail to pick up signals from
gliders below, and I suspect it has limited range of gliders on the
same level in some directions where they are partly masked by the
fuselage. This, however, should have no effect whatsoever on the GPS
logging capability.

Hope this helps to inform those discussing the issues on this thread.

Chris N