Hi Rob
I have fitted PilotAware permanently in my Sports Cruiser which is similar construction but not as fast as the VANS. I have put a paper on this on the website at
http://www.pilotaware.com/wp-content/uploads/2016/09/160915-Permanent-Installation.pdf have you seen this?
It makes it really convenient, just hit the master switch, wait for the iPad to log onto the WiFi select Skydemon etc and go. The range on 3PI is over 30Km and the ADSB insane at 200Km plus, absolutely useless of course but nice to see. Antennas are located underneath the aircraft.
The offered one is this http://pilotawarehardware.com/product/tuned-monopole-whip/.
However the info on it is a tad scant, aside from it needing a ground plane (not an issue on an aly airframe).
Is it definitely weatherproof?
Does it include all mounting hardware?
Will it put up with high airspeeds (210mph for the RV-6's VNE, more for RV7s, 8s and 10s).
How long can the lead be?
What is the end connector?
Cant say its definitely waterproof but I use petroleum jelly on the interface as a barrier.
It doesn't include the mounting hardware but this is in the list above.
I use an aluminium ground plane about 6*8cm to spread the load on the inside and a penny washer on the outside. The airframe is then the earth plane as you say and is brilliant.
You can get the extension leads from pilotawarehardware.com and one should be long enough. Its in the list
The end connector is SMA
Speed. If you are flying at this kind of speed then you may want to log at a more flexible antenna which will bow slightly with the friction but works well. There are available from Paddy Magee <
paddy@industrial-remotes.com> Paddy will build you tuned antennas one for pilotAware 869.5MHz and one for 1090MHz. They are very good.
Next question is whether to mount the above monopole on the topside or underside of the aircraft?
Has anyone tried either, and with what results?
Is both, diplexed, an option?
Bottom works great for me and makes the cable runs easy also keep it out of the wet somewhat.
I don't know about duplexed - I haven't done it - would this not affect the output impedance? It would be great if you could as this would improve efficiency in all directions.
Anybody have experience/solutions for any of this?
I am reluctant to drill holes in the plane without any kind of idea as to whether it is a good position or not.
Presumably other RV's, Sport Cruisers, Zenairs and other low wing, highish turtledeck metal aircraft have similar issues.
I would have no hesitation to drill the holes as the results are very worthwhile, but make sure you get the right authorisation from the LAA if that is your licensing authority.
Cheers
Keith