PDA

View Full Version : Antenna placement



inzersv
09-03-2014, 07:09 PM
I will have a Dynon GPS, an ELT, a Dynon transponder,a Dynon ADSB, and a COM antenna. Where do all of these antenna's go for my Super Sport. Do the transponder and ADSB use the same type of antenna and if so can they run off of one antenna with a splitter? I have been searching this forum for some answer's and haven't had much luck. Any thoughts, help or what have you is much appreciated. Photos of installations would be helpful. Thanks as always.:eek::rolleyes::confused:

Av8r_Sed
09-03-2014, 08:34 PM
Technically it's possible to use one antenna for the transponder and ADSB. I believe you would use a diplexer rather than a splitter, but... those little stick and ball antennas are inexpensive and lighter than adding the gear to share one. I would just stick with dedicated antennas. Use care to provide proper separation between the different antennas. This is usually specified in the installation manuals.

PapuaPilot
11-28-2014, 10:33 PM
I have the same question as the original post, which really didn't get answered. The question was where do you put the ADSB antenna? I will be using a Garmin GTX23 & GDL-39R, which I am planning on mounting in the aft fuselage, behind the baggage area (to help get my EWCG farther aft).

I already have the antennas for the ADSB & Xponder. Part of the problem is that you are supposed to keep the ADSB 36" from the transponder and COM antennas. My model 5 doesn't have another dedicated mounting place. Right now I have the COM and 406 ELT antennas on the top behind the turtleneck and can put either the ADSB or Xponder on the bottom behind the pilot's seat. Garmin says to put the ADSB antenna on the bottom, but where can you put it considering the 36" distance, structural strength, ground plane, etc.?

BTW the inexpensive stick and ball antenna doesn't meet the specs required for an ADSB antenna. I have a TSOed blade antenna for ADSB.

Dorsal
11-29-2014, 05:14 AM
I use a stick and ball for my ADSB and have mounted it inside the tail. I used a small Aluminum plate mounted in the front lower part of the horizontal stabilizer pass-though with the antenna pointed down. This could suffer from some signal degradation from the frame but appears to work quite well. I use it mostly to trigger the system for my GDL 39 which is up in the instrument panel. COM antenna; top rear mounting plate, ELT; internal, Xponder; plate behind pax seat.

PapuaPilot
11-29-2014, 08:14 AM
Hey Dorsal,

Yeah, I am worried about the signal being degraded if I mount it inside. I found some more info about this on the Vans blog last night. An engineer from Dynon says their isn't much loss of performance between using a TSOd antenna and the stick one (that isn't even for the correct frequency). It was still performing at about 90% of the TSOd part. He stated something like "if the TSOd antenna picks up the signal at 33 miles the stick one will do the same at 30 miles".

I have my antennas already and the TSOd blade antenna was free! So that isn't the issue, its where to put them and get the best reception.

Do you have pictures of you installation of your antenna?

jrevens
11-29-2014, 10:48 AM
The "stick & ball" antennas can be TSO'd or not. They are dirt simple and are the same either way. They are designed for a frequency range of 1030 to 1090 MHZ, which is just fine if you're using a mode S w/ ES transponder - which operates on 1090 MHZ. If you're using a UAT, it operates at 978 MHZ, so not quite optimum for the stick & ball, but it works. The blade types are designed for a little wider frequency range, and usually for transponder & DME operation, so they get down in that 978 MHZ range by design.

I was planning to install an aluminum plate centered on the belly, forward under the tunnel for my UAT antenna. The coax would then come up between the rudder cables, with a relatively short run to the panel. That would put it over 3 feet from my Mode C transponder antenna which is on the factory installed plate behind the passenger seat. Any thoughts on that location?

neville
12-02-2014, 07:29 AM
On my super sport the comm ant is mounted on the provided plate on top
just behind the turtle deck. The transponder ant is a stub/ball mounted on
the existing plate just behind and below the header tank. The ads-b ant is
a blade type mounted on a fabricated ground plane about mid way between the aft end of the baggage compartment and the leading edge of the horz stabilizer on the underside of the aircraft. The elt ant is mounted inside the vertical stabilizer above the horz stab. All work well.

The ahrs for the Advanced 5600 is mounted in the right wing second bay in from the tip. No apparent interference from any electrical system operation. The angle of attack ports are installed in the left wing in bay before the tip. Also works well. The AOA system is the only way to go.
It allows very good short field t/o and landings with good warning of critical angle of attack.

PapuaPilot
12-02-2014, 09:16 PM
Neville,

Do you have any pictures of your ADSB antenna installation?

neville
12-03-2014, 08:45 AM
Not the best but here are some. To see the drawing click on link 002 below last picyure

PapuaPilot
12-03-2014, 09:20 PM
Thanks Neville, that's what I was looking for.

PapuaPilot
12-06-2014, 08:46 PM
Here is my installation of the transponder antenna. It is under the co-pilot's seat and is 3' from the factory mounting plate behind the pilot's seat where I put my ADSB antenna.