I have a PowerFlarm portable mounted on top of the glare shield of my
Stemme.Â* Also on the glare shield, in vertical orientation, are the
Flarm A & B antennae and the ADS-B antenna.Â* The Stemme is of all carbon
construction (except for a few parts).Â* One day I was flying a couple
thousand feet directly above another local pilot in a Discus 2, also of
carbon construction.Â* Though I could see him visually, neither of us
could see the other on Flarm as my antennae were above the carbon hull
of my ship and his ship was directly below.Â* I rolled up into a steep
bank and we each "saw" the other on the PF displays.

I good way to have all around coverage would be to place an external
antenna on the belly of the aircraft, but my PF unit only transmits on
the "A" antenna.Â* The "B" antenna is receive only.Â* I could get better
coverage below if I moved the antennae to the canopy frame but still
nothing directly below that was close enough to be a threat (and I'd
have a mess of cables to contend with).

On 5/10/2018 9:44 AM, K m wrote:
On Thursday, May 10, 2018 at 7:07:15 AM UTC-7, Matt Herron Jr. wrote:
Flarm antennas are a real pain for ships with carbon hulls. Coverage is always poor, especially below. Is there a way to make a perfectly flat and thin antenna that could be taped to the outside of the hull and fed through a small (1/8"?) hole? I am thinking 2 thin wire strands, or foil strips, fed through from the inside, then taped in place with wing tape. I would put one on either side of the nose for good coverage. The wires could even be longer (some wavelength ratio) for better gain. The tiny hole could easily be filled later if the install was reversed.

Any RF engineers out there care to take a shot at this?
Matt,
Not an RF Engineer but I am a self appointed internet expert and I think you and I have the same type of ship. Richard at Craggy sold me a whip (I have also heard this referred to as a duck) antenna to mount on the glare shield. Not sure how it would do directly beneath me (Would probably be in a turn if that were the case) but I get max range for transmission and reception. PM if you need a pic or call Richard.
Kirk

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Dan, 5J