New Delta Pop Transponder Antenna

Recently Don Pansier of Delta Pop Aviation asked if I would test fly and review his newest blade transponder antenna. I happily agreed, and I have nothing but great things to say about the antenna.

I’ve recently been running a Comant 105, after replacing my TED antenna in search of lower drag and more speed. My first impression of Don’s new design is that it’s a sleeker and thinner blade with very smooth lines. The mounting pattern is identical to the Comant 105, so the swap required no drilling, and took just minutes.

Here are a few pictures of the antenna, side-by-side with a Comant 105, and mounted on the plane.

DP foreground, Comant behind:


Head-on, DP on right:


From above, DP on right:


Nose on, DP behind:


Mounted on the belly:


Here’s one of the Comant (L), a TED, and the DP (R):


Believe it or not, a typical TED antenna reportedly has about 4 times the drag of a typical blade antenna. That data is taken from a soaring website that compared a RAMI rod & ball antenna (0.41 lbs drag) to a RAMI blade antenna (0.09 lbs drag) (both measured at 250 mph).

I did speed tests before and after I swapped the DP in for the Comant, and saw no speed difference between the two blades (just one 4-way test each, FWIW). However, going from the TED to a blade last year did seem to yield a little speed, but I was swapping multiple antennas and doing multiple experiments, so I can’t attribute specific gains to the blade…there may just be some small incremental advantage to a blade (I’m hopin’!)

Don’s blade is slightly taller, with a slightly larger base footprint, but as mentioned above, it’s noticeably thinner and has smoother contours. One thing I can give a very positive report on is its performance. On my recent trip to Taylor, Texas for the SARL race there, and then back to Reno via Phoenix, I had great coverage with ATC (flight following through or around several MOAs and into one Class B), and my Monroy traffic watch worked normally. Great results for this sleek antenna!

This new antenna is not yet up on Don’s website, but if it’s priced as competitively as his other antennas, this looks like a great buy…and it just looks kinda cool too! It definitely looks faster!

Thanks for the opportunity to test this antenna Don…looks like a winner to me!

Cheers,
Bob

I don't want you to think I spy but ...



This is the photo I took of your new antenna installation at Taylor. I still have the spike on mine. I wonder about the alignment to the line of flight affect on speed both from the perspective of the installation and different flight conditions. The spike is the same no matter what I do.

Bob Axsom

Bob,

The alignment of the blade would be a factor if off, but its not hard to get it to line up down the longitudinal axis of the plane (rivet lines are your friends!)

The ball and stick, though omni-mountable (is that a word ), is said to be quite a bit more drag. At Airventure Cup, Larry Vetterman looked at the two I had on my belly (XPNDR and Monroy), and told me switching each one to a blade would be a knot apiece. So I put the Monroy TED on the glareshield, and put the XPNDR blade where the DP antenna now sits. Next race was my first one over 245, so maybe it did something!

Now if I could just get my radio to work 100% from the wingtip antenna (I'm close), I'd clear that last Comant whip off too!

Any ideas from Delta Pop on that Don?

Cheers,
Bob

We've got Don's Transponder and TWO of his Comm antennas hanging on the belly of the RV-3 project right now (now that he's up on the gear). I can't speak to the speed of the transponder antenna, but I can tell you that the first time we powered up, I was getting reply activity on the transponder display...sitting on a cradle...in our hangar...at our private airpark....pretty good RF performance if you ask me!

Paul

Here's a thought

Remove all of the antennas for racing as long as there is no Class B or C around and use a hand held with the rubber duck mounted on the glare shield and a pust to talk taped to the stick. I'll hold off on that until Mike Thompson beats me in the BV Blue Class ... but it's in the desparation basket. I think Larry's estimate is a bit optomistic.

Bob Axsom

Ironflight said:

We've got Don's Transponder and TWO of his Comm antennas hanging on the belly of the RV-3 project right now (now that he's up on the gear). I can't speak to the speed of the transponder antenna, but I can tell you that the first time we powered up, I was getting reply activity on the transponder display...sitting on a cradle...in our hangar...at our private airpark....pretty good RF performance if you ask me!

Paul

Click to expand...

It really is a nice little antenna...very high quality workmanship, and light too. Since I'm going further OT below, just wanted to quote Paul to keep some focus on Don's antenna!

Bob Axsom said:

Remove all of the antennas for racing as long as there is no Class B or C around and use a hand held with the rubber duck mounted on the glare shield and a pust to talk taped to the stick. I'll hold off on that until Mike Thompson beats me in the BV Blue Class ... but it's in the desparation basket. I think Larry's estimate is a bit optomistic.

Bob Axsom

Click to expand...

This thought has definitely crossed my mind too Bob. However, when "hunting" Rockets, its not desperation, its just good ol' fashioned cheatin'...and you know what they say about "if ya aint cheatin"...

I tested a bent whip JB welded to an 8"x8" ground plane attached to the inside of my left wingtip all the way to Taylor, and it worked pretty well (best tip antenna test to date). Lots of flight following, and some controllers reported it L&C, while others called it "a bit scratchy". I may try a larger ground plane next. Trouble is, the ground plane won't fit in the flat racing wingtip, so I left the belly whip on. Another experiment will be a j-pole down the left gear leg...its already placed in there...just gotta work the connections...we'll see!

John Huft had all antennas buried except the transponder, but the comm antenna details are not on his site. Hmmmm, perhaps a call to Colorado...

Still would love to see a Delta Pop hidden RV comm antenna...as long as it won't fit on a Rocket!

Cheers,
Bob

Bob and Paul, thanks for the reports on the Transponder antenna, happy to hear the performance meets your expectations.

I've had several questions regarding the future of my transponder antennas, just to clarify, my plans are to offer both antennas.

The standard transponder model ($59.95) will handle the needs of the majority of aircraft builders and the very low drag model ($89.95) for the builder who is looking to minimize every bit of drag possible.

Regarding the comments on Com antennas:

I would love to come up with a good reliable alternative for the exposed Com antenna and will continue to develop and test options in that direction.
Having flown part 135 years ago I can tell you there were times when I gladly would have given up airspeed for reliable communications. Those experiences have influenced my design philosophy to provide low drag antenna products that will perform at the highest levels and never be the weak link in the communication or data system.

Great price too Don! I paid $135 for my other blade at OSH, so either of your transponder antennas is a great deal!

Concur with your assessment of comm reliability...why the whip remains on the belly till an all-aspect, always-working hidden antenna is found (or fabbed), tested and proven (which may be a long time!). I don't want to be the NORDO guy out there, monkeying up the works!

Cheers,
Bob

Thanks Don

Wanted to give a shout out concerning Don and his customer service. I bought his regular transponder and bent whip com antenna. I had a concern about the drag on the com antenna I received and Don sent out a replacement pronto - no questions asked. Check off another happy customer.