Deltapop low drag antenna

[C-FAH Q]

I received a low drag transponder antenna from Don Pansier at Deltapop aviation. I race my plane and every little bit of drag reduction helps. This antenna has about a quarter the drag my stick and ball transponder antenna has.
Right out of the box I was impressed, it looks very well made and is wayyyyyy thinner than I had ever imagined. Looking at it straight on, it is super thin as you can see in the pics below. If I said it took 20 minutes to install, I would be lying, 10 minutes is all it took to retro fit it into my old antenna spot. Enlarge the hole to 9/16", drill two 3/16" holes for the mounting screws and that's it. Tighten the nUts to 20 inch pounds, attach the bnc connector and that's it,and I didn't even stay at a Holiday Inn last night!
Anyway, very happy with it, great product Don.
http://www.deltapopaviation.com/Delt...tion/Home.html

[Alan Carroll]

Gary - must be good for at least two knots I'm sure!

[Bob Axsom]

I bet you had to say that just to get a rise out of me. Gary, are you going to give us some precise test results?

Bob Axsom

[C-FAH Q]

Alan,
I have found a few knots...all in my tie down ropes!
You coming to the GCAR this year?

[C-FAH Q]

Originally Posted by Bob Axsom

I bet you had to say that just to get a rise out of me. Gary, are you going to give us some precise test results?

Bob Axsom

Bob,
No precise test results in my books. As long as I can close the gap on Alan and Jason, I will be happy. I need to learn how to race a smarter race. In the Rocket race last November, Jason passed me. He flew a smarter race, and I blew a couple turns. On the way to the radome, I was behind him by a mile, by the time we got to the radome, I could have shook hands with him. I have the speed, just not the ability.......yet!

Hope things are drying out at home.

[Bob Axsom]

All is dry here but south and east the situation is bad.

The reason I made my post earlier is, 2 kts is a fantastic gain in top speed and You guys know that. There is no doubt if the streamlined antenna in installed precisely inline with the airplane's flight direction it will create less drag so I'm sure it is a good thing.

If there is good reliable test data that showed the antenna to yield even a 1/4 kt increase in speed I would put an access door in the seat pan and remove the antenna for races. The air is so disturbed there aft of the cooling air outlet that I doubt it even knows there is an antenna there. Now if I could come up with the right centerline cooling air flow fairing to enclose the xpndr antenna I might have the best of both worlds.

Bob Axsom

[mosquito]

Hi Bob... what about a wheelpant installation? My -6 has it's transponder antenna installed in it's right side wheelpant (pressure recovery type). There's a BNC on the rear bulkhead of the pant. I _hope_ it's installed in the cavity in the proper orientation with a hefty horizontal piece of metal, but I can't figure any way to know short of opening up the wheelpant. Not sure how it can be reasonably grounded in this configuration, but nonetheless, it seems like it would be a great way to reduce drag... if it worked.

Unfortunately... my transponder has had pretty spotty performance, with frequent loss of mode-c. Last cross country w/flight following had problems with every controller So I ordered a Delta Pop antenna, which I received this weekend, and it will be going into pre-existing holes behind the right gear leg.

It will be interesting to see if I slow down and/or get decent coverage. I have to wonder why the builder relocated it in the first place. If performance remains bad, I guess the KT76 is suspect.

Any history of wheelpant installations, or was my builder... experimenting?

-jon

[Bob Axsom]

Bob Mills and I discussed the idea briefly for a bent whip com antenna installation at the Taylor race in April. It's a thought ... with all of the expected problems I'm sure.

Bob Axsom