Dual PowerFLARM Antennas: Teamwork or Duel?

Sorry, fun with words.

Does anyone know how PowerFLARM handles inputs from two antennas, "A" and "B"? Does it select the strongest signal source? Or, alternatively, does it somehow integrate inputs from two different antennas and use the combined information?

In an attempt to increase range, I installed a "B" dipole antenna (the receive-only port) on my Portable PowerFLARM and flew with it this weekend. The "A" antenna (transmit-receive) is the factory "stick" antenna that sits on the rear of the unit, which is mounted on the top of the glare shield.

With the stick antenna only, I had a big lobe out to the left side (per the range analyzer tool) and pretty unimpressive reception in all other directions. After I reset the software (see recent related thread), I temporarily installed the dipole low on the right side of the glareshield.

Success! Much better reception on the right side. No surprise--the mass of numerous instruments shields the left side of the dipole. What WAS a surprise was that the big lobe out to the left is now gone: i.e., reception there has gotten worse.

Overall I'm somewhat better off, though the marginal reception straight ahead hasn't improved.

Does it matter that the two antennas are of different types?

I've checked other threads and it seems like the brick owners are using two dipoles to cover different areas of the sky (left & right, front & rear, above & below). Underlying everything I've read is that two antennas are better than one, providing combined coverage. That's not exactly what appears to have happened in my case.

I've had experience in the past installing a homemade VHF dipole in the rudder of a glider where the existing factory antenna a few inches forward of it in the vertical fin apparently acted as a parasitic element and made the add-on antenna extremely directional. IIRC, the stick and dipole are perhaps 30 cm apart.

I should also mention that I have one of the three or so Schleicher gliders in the U.S. with the factory canopy wire (fence) deflector bars, with the front hoop of steel tubing arching over the cockpit just aft of the instrument panel. Another potential challenge for antenna positioning.

Finally, since the Portable is mounted on the glareshield, I'm very reluctant to mount a dipole in the nose (as the ASW 27/29 crowd have done) unless I can provide a friction-fit disconnect in the coax or insure the antenna itself will separate cleanly from the glider if I have to jettison the canopy.

Ideas?

Chip Bearden
ASW 24 "JB"