On 7/19/19 9:38 AM, John McCullagh wrote:
I have a new glider on order and naturally I want to build-in all the
things it will need over the next ten years at least, rather than adding
things later piecemeal. In the non-carbon part of the fin I plan to have a
radio aerial, a transponder aerial and a Flarm aerial. However it seems
that ADS-B (In & Out) is the coming thing and so presumably another
built-in aerial would be a good idea, rather than something above the
instrument panel. Have anyone fitted four aerials in the fin and do they
co-exist happily with each other? I don't know if differences between
European standards and US standards would make a difference to the type of
aerial fitted.


European and U.S. radios only differ in channel spacing, so they would
use the same type of aerial. I would prefer to put the transponder
antenna down low near the main gear, since it's very high power and
could interfere with receivers. ADS-B out is usually the same output as
the the transponder, so no need for separate antenna. ADS-B in is a
small antenna, receiving very high power signals, so placement is not
critical.

PowerFlarm uses very small cables with high loss, don't think they
belong in the tail. Do the best you can with them near the glare
shield. Maybe you run a Flarm B cable all the way to the tail, but I'm
dubious of the benefit. Definitely wouldn't put a Flarm antenna
anywhere close to transponder output.

Dave