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Delta Pop UAT antenna with Garmin GDL-39

dpansier

dpansier

Well Known Member
I recently received these screen shots from a Dallas area customer that installed a Delta Pop UAT antenna on the lower fuselage feeding a Garmin GDL-39 receiver.

Prior to installing the Delta Pop UAT antenna, the GDL-39 with the stubby antenna was positioned on the glare-shield allowing reception from 1 and sometimes 2 ground stations.

With the external Delta Pop antenna the ground station count went as high as nine all with excellent signal quality.

Needless to say he was very happy with the results.

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I'm getting close to pulling the plug on XM and installing a GDL-39, it will definately have one of your antenna's on it!
 
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Ah, thats nice to see and read...I have this same configuration, although not flying yet. All of my antenna's have been purchased from Don, you wont find a better product for a lower price with excellent customer service.
 
Questions

Interesting screen shots, I have the GDL39 on the dash and in the Tulsa area on my first test currently get no ground stations. I assume if you remote the unit you will also have to use an external GPS antennae as well as the UAT antenna.
Also I did not appreciate that you can update the GDL39 over bluetooth from the iPad, in my case the 39 is hardwired to the 796 which updates the GDL39 automatically. I wonder if it matters if a later version of Garmin Pilot updates the GDL39 to a rev level different to the code embedded in the 796 as these seem to be on different release cycles.
 
Question for the Garmin experts:

The Garmin GDL-39 manual states the following information for mounting an external ADS-B antenna in bold below.

Unless I missed it in the manual, would you please clarify the minimum distance required from the Transponder antenna to the external ADS-B antenna.



"3.3 GDL 39 Location and Mounting
3.3.1 Location
For best reception position the GDL 39 where it has a clear view of the sky. If the unit is placed on the glare shield it may get very hot due to the direct sunlight and reduce the operating life of the unit. The GDL 39 antenna, internal or external, should be mounted at least 3.3 feet (1 meter) away from the path of any radar beam or a VHF radio antenna. The GDL 39 should be mounted at least 6 inches (10.24 cm) away from a magnetic compass. If using an external ADS-B antenna, it is recommended to locate the antenna on the bottom of the aircraft for best ground station reception."

Thank you
 
uk_figs said:
Interesting screen shots, I have the GDL39 on the dash and in the Tulsa area on my first test currently get no ground stations. I assume if you remote the unit you will also have to use an external GPS antennae as well as the UAT antenna.
Also I did not appreciate that you can update the GDL39 over bluetooth from the iPad, in my case the 39 is hardwired to the 796 which updates the GDL39 automatically. I wonder if it matters if a later version of Garmin Pilot updates the GDL39 to a rev level different to the code embedded in the 796 as these seem to be on different release cycles.
Click to expand...

Yes, you will have to have an external GPS antenna if you locate GDL under your dash where you can't get reception. I think the little Garmin GPS antenna I got and put on the glareshield was about $29 which works great. It's probably the same antenna that came with your 796. No need for external mounted GPS antenna.

I have my GDL connected to a 696. I also connect to it with my iPhone using the Garmin Pilot software. When I connect to it with the iPhone the iPhone will automatically download any updates using the cell network and install them automatically. Very cool. It was no fun in the past pulling stuff out of the airplane and taking home to update.
 
We recently took a trip from Houston to Sedona and went south of White Sands out and north of it on the return leg. At all times we had a <5 minute update time and never once lost data reception. It was typically <2 minutes. Our 39 is sitting on the glareshield of a Mooney 201. It truly is an awesome unit.

All through texas it continuously has 5 stations in contact above 1500 AGL.
 
dpansier said:
Question for the Garmin experts:

The Garmin GDL-39 manual states the following information for mounting an external ADS-B antenna in bold below.

Unless I missed it in the manual, would you please clarify the minimum distance required from the Transponder antenna to the external ADS-B antenna.



"3.3 GDL 39 Location and Mounting
3.3.1 Location
For best reception position the GDL 39 where it has a clear view of the sky. If the unit is placed on the glare shield it may get very hot due to the direct sunlight and reduce the operating life of the unit. The GDL 39 antenna, internal or external, should be mounted at least 3.3 feet (1 meter) away from the path of any radar beam or a VHF radio antenna. The GDL 39 should be mounted at least 6 inches (10.24 cm) away from a magnetic compass. If using an external ADS-B antenna, it is recommended to locate the antenna on the bottom of the aircraft for best ground station reception."

Thank you
Click to expand...

Mr. Pansier,

The minimum antenna separation distance for a transponder antenna is similar. 3 feet minimum with 5 feet recommended.

Steve
 
I just completed the same install. Used the DeltaPop antenna on the bottom of my RV-6A and used a Garmin 'inside' antenna puck on top of the dash. Works great and let me bury the GDL-39 so it didn't sit on the panel (doesn't look that good and the stick antenna is a bit tall!).

This is my second DeltaPop antenna, I can't say enough about them!

Regards,

DWS
RV6-A N142DS
www.n142ds.com
 
g3xpert said:
Mr. Pansier,

The minimum antenna separation distance for a transponder antenna is similar. 3 feet minimum with 5 feet recommended.

Steve
Click to expand...

Thanks Steve for the clarification on the min distance.

Thanks guys for the compliments on the antennas.
 
Is Delta Pop good enough?

I?m about to purchase the external antenna for my Garmin GDL39 ADS-B Receiver. Everyone is raving about the Delta Pop UAT antenna. The GDL39 is dual frequency (978MHZ and 1090ES). The Delta Pop antenna specs says it is good for 978 MHZ with no mention of the 1090 band. What do I give up by not having the 1090 band too? Is there a different antenna that is optimized for both bands within the GDL39?
 
bobmarkert said:
The Delta Pop antenna specs says it is good for 978 MHZ with no mention of the 1090 band. What do I give up by not having the 1090 band too?
Click to expand...

I asked Don that exact question. He was quick to help ...

The ADS-B / UAT antenna I offer exceeds the requirements spec'd by Garmin. The antenna is also used with the Dynon, Navworx and several other ADS-B / UAT devices.
Click to expand...

Addendum (29-Jan-2014): I've had the Delta Pop ADS-B antenna for a year now. I love the performance of the GDL-39 with it. I can't believe I flew without live weather for so long.
 
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How would you compare and contrast using the UWB Antenna (800 MHZ to 2000 MHZ Ultra Wide Band) vs the UAT Antenna (978 MHZ) for ADS-B reception?
 
The UWB Data antenna electrical performance is within the spec?s published by Garmin for the GDL-39 but that was not the design intent for that antenna.
If you have the antenna and wish to use it for that purpose it will perform well, if not, I suggest the ADS-B / UAT antenna which is less expensive.
 
Don, I'm interested in using your Ultra Low Drag Transponder Antenna for ADS-B with my GDL 39R. Will this antenna be as effective as your UWB antenna?

Thanks,
Russ
 
The Ultra Low Drag Transponder antenna will perform well with the Garmin GDL-39 and is within the VSWR spec?s
published in the Garmin manual shown below.

The Ultra Wide Band Data antenna was designed to be effective over a wide frequency range with a VSWR of less than 2:1
between 800 to 2000 MHZ. This antenna will perform well with the Garmin GDL-39 as it is within the VSWR spec?s but this
was not the design intent for the antenna.

The Delta Pop UAT antenna was developed for use with the many ADS-B / UAT devices on the market and is the best antenna in
my product offering for that purpose. The Ultra Low Drag Transponder antenna will perform well in the ADS-B / UAT application but is more expensive.
The design intent for the ULD Transponder antenna was to offer min drag for the racers looking to squeeze out every last knot.





3.2.2 External ADS-B Blade Antenna (Optional)

A blade-type ADS-B antenna is mounted on the exterior of the aircraft. Connection is made by unscrewing the

antenna on the GDL 39 and attaching the cable from the external antenna to the female SMA connector on the top of the GDL 39.

The GDL 39 requires a UHF antenna that meets the following specifications:

? Standard 50 ohm vertically polarized antenna with a VSWR < 1.7:1 at 978 MHz and < 1.5:1 at 1090 MHz.
 
If you have a Stratus 1 (possibly 2 as well) the connector for an external ADS-B antenna is a Hirose MS-151-C(LP). Google that and you can find some cables that terminate in an SMA and you can convert to the BNC for Don's antenna. Don't try to build your own cable unless you like micro-surgery. That connector is a PITA. Trust me...
 
dpansier said:
The Ultra Low Drag Transponder antenna will perform well with the Garmin GDL-39 and is within the VSWR spec?s
published in the Garmin manual shown below.

The Ultra Wide Band Data antenna was designed to be effective over a wide frequency range with a VSWR of less than 2:1
between 800 to 2000 MHZ. This antenna will perform well with the Garmin GDL-39 as it is within the VSWR spec?s but this
was not the design intent for the antenna.

The Delta Pop UAT antenna was developed for use with the many ADS-B / UAT devices on the market and is the best antenna in
my product offering for that purpose. The Ultra Low Drag Transponder antenna will perform well in the ADS-B / UAT application but is more expensive.
The design intent for the ULD Transponder antenna was to offer min drag for the racers looking to squeeze out every last knot.





3.2.2 External ADS-B Blade Antenna (Optional)

A blade-type ADS-B antenna is mounted on the exterior of the aircraft. Connection is made by unscrewing the

antenna on the GDL 39 and attaching the cable from the external antenna to the female SMA connector on the top of the GDL 39.

The GDL 39 requires a UHF antenna that meets the following specifications:

? Standard 50 ohm vertically polarized antenna with a VSWR < 1.7:1 at 978 MHz and < 1.5:1 at 1090 MHz.
Click to expand...
Thanks for the response Don. So it sounds like the Ultra Low Drag antenna would work fine, but the UAT would be best, reception-wise.

But if the reception of each were equal, I'd lean towards spending $20 for a hair less drag. :)

Thanks again,
Russ
 
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