Wingtip Antenna

I recently moved my APRS antenna from a vertical Byonics antenna mounted on the rail behind the seats to a "J-Pole" in the right wing tip. I don't judge the reception to be significantly better. The next step is to increase the power to something larger than 300 mW or to buy a belly antenna. Having it on the seat rail was a nuisance since it was in the way. Here is the URL of my last flight. http://aprs.fi/?call=ki6rgh&mt=m&z=11&timerange=86400
Leland

Antenna

Leland said:

I recently moved my APRS antenna from a vertical Byonics antenna mounted on the rail behind the seats to a "J-Pole" in the right wing tip. I don't judge the reception to be significantly better. The next step is to increase the power to something larger than 300 mW or to buy a belly antenna. Having it on the seat rail was a nuisance since it was in the way. Here is the URL of my last flight. http://aprs.fi/?call=ki6rgh&mt=m&z=11&timerange=86400
Leland

Click to expand...

Leland:

I should think that at your altitude you should be getting more "hits" than I see on your flight. A belly mounted whip will greatly improve your signal strength.

I have a 10 watt "All in One" Byonics rig with the J-pole mounted in the wing tip and you can see the coverage here in Georgia. Admittedly the flight was over much flatter countryside, but at your altitude there. you probably should have had more coverage.

Here is my last flight.
http://aprs.fi/?call=n161rl&mt=m&z=10&timerange=86400

If you'd like click on 2008 in the "Select a Day" then select Dec 29 (mon 205 points) and click. There you can see my flight back home from our visit to the kids/grandkids in TX.

Had headwinds of about 15kts to start and diminishing to direct crosswind around Birmingham, with 2 or 3 knot tailwind around the Alabama/Georgia Border.

Maybe Sam and some of the more knowledgable aprs guys can chime in.

Weak performance from wingtip

I built the J-pole antenna and had good results from taping it to the inside of the canopy. I'm using the 300mW version. I recently moved the antenna to the left wingtip using Pete's method of taping it along the bottom of the fiberglass wingtip and getting a little vertical section near the front of the wing. Performance around Denver was notable worse. I'm in the process of building a belly antenna and I'll report how that works. I don't think you need to put more power out; I think the key is reducing blockage by going to the belly antenna. That is what I am trying.
Rick

Antenna Polarization

I suspect that the majority of the ground stations are using vertically polarized antenna. Therefore for the best range for you aircraft the antenna should also be vertically polarized. If you your antenna is horizontally polarized you will have a 30db drop in signal, which is significant.