Author Topic: External antenna reccomendation?  (Read 9169 times)

Easy Cruising

External antenna reccomendation?
« on: September 17, 2018, 04:50:17 pm »
Hi all. Have been using PAW for quite a while now. Working nicely. I'm considering an externally mounted aerial for reception of ads-b/090. Can anyone suggest such an antenna ? I see that PilotAware sells an aviation grade external antenna kit but I dont need the whole lot, just the adsb antenna and cable. Is this an item that anyone has found on ebay/amazon etc? Additionally, is it better mounted on top or bottom of the aircraft , or makes no difference ? I know this was previously discussed but I can no longer find the previous thread on the forum.

Admin

Re: External antenna reccomendation?
« Reply #1 on: September 17, 2018, 05:18:54 pm »

Easy Cruising

Re: External antenna reccomendation?
« Reply #2 on: September 17, 2018, 05:50:06 pm »
Thanks Lee. I was hoping not to have to buy a whole kit just to get 1 antenna, hence asking about ebay/amazon.

exfirepro

Re: External antenna reccomendation?
« Reply #3 on: September 17, 2018, 06:14:49 pm »
EC,

If you don’t want to buy the full PAW External Antenna Install Kit, you could use a ‘standard’ transponder antenna, e.g.....

https://www.gps.co.uk/harrys-hm109s-stub-transponder-dme-antenna/p-0-1894/

...though you will need to sort out your own cable.

In view of the relatively high power transmitted by 1090MHz devices, the only issue with siting is to ensure as good a view through 360 degrees as possible. Yes the antenna will be ‘blocked’ through a metal aircraft body - but you will have already seen the other aircraft long before it gets anywhere near you. Just keep the antenna away from your own transponder antenna (and a sensible distance away from other VHF or GPS antennas) to minimise risk of interaction.

Regards

Peter

Easy Cruising

Re: External antenna reccomendation?
« Reply #4 on: September 17, 2018, 07:40:07 pm »
Thanks exfire.

jollyrog

Re: External antenna reccomendation?
« Reply #5 on: September 21, 2018, 10:44:03 pm »
External aerials. TED 104-17 for combined 978MHz UAT and 1090MHz ADSB reception on left wing root and Pulse Engineering SLPT806DMNW for 868MHz PilotAware transmission & reception on right.

https://www.facebook.com/photo.php?fbid=10213888559960471&set=a.1121865299156&type=3

david_lacey

Re: External antenna reccomendation?
« Reply #6 on: November 02, 2018, 10:44:27 am »
I flew G-BIID with PAW for the first time yesterday.  For the external antenna I have gone for a custom-built, dual frequency (1090MHz and P3i) MIMOCONE from Badland of Stourbridge.  It cost about £60 including feeders and tails to my specification.  It seems to work very well although it is early days.  I have attached a picture of the installation on the starboard tank cover.

Admin

Re: External antenna reccomendation?
« Reply #7 on: November 02, 2018, 02:32:46 pm »
I flew G-BIID with PAW for the first time yesterday.  For the external antenna I have gone for a custom-built, dual frequency (1090MHz and P3i) MIMOCONE from Badland of Stourbridge.  It cost about £60 including feeders and tails to my specification.  It seems to work very well although it is early days.  I have attached a picture of the installation on the starboard tank cover.

Hi David,
Can you elaborate on how this was customized for both 1090Mhz and 869Mhz ?
because of course these are very different wavelengths
Thx
Lee

david_lacey

Re: External antenna reccomendation?
« Reply #8 on: November 02, 2018, 03:37:44 pm »
Hi Lee
I haven't looked into the detail of how they are tuned, but there are a number of companies offering this type of aerial, and there is more than one profile.
I suggest that you contact Adrian Badland and ask him how it is done - https://www.badland.co.uk/
I suspect that the elements are tuned to length somehow prior to being encapsulated within the outer cover, but that is just a guess.
During testing we demonstrated reception of ADS-B traffic and reception/transmission on the P3i frequency (869.5MHz?)
Hope this helps
Dave

 

Deker

Re: External antenna reccomendation?
« Reply #9 on: November 02, 2018, 05:35:33 pm »
It is common to have an antenna that will operate on multiple bands.
What I can't understand is how the TX of the P3i does not feed into the ADSB RX dongle without the use of a diplexer?


david_lacey

Re: External antenna reccomendation?
« Reply #10 on: November 03, 2018, 12:22:52 am »
I think that it is two distinct aerials in a single assembly.  Each has its own individual feeder.

exfirepro

Re: External antenna reccomendation?
« Reply #11 on: November 03, 2018, 09:39:38 am »
An interesting option, David,

Please keep us posted on perceived performance as you gain further experience of the antenna  ‘in flight’.

Regards

Peter

david_lacey

Re: External antenna reccomendation?
« Reply #12 on: November 03, 2018, 10:02:17 am »
Will do.

david_lacey

Re: External antenna reccomendation?
« Reply #13 on: November 05, 2018, 07:13:33 pm »
Just did a quick analysis of the TRK file from my trip last Thursday, and counted 51 contacts - mainly airliners but including a C152, a Cirrus, a Beech 200 ambulance out of Glasgow and an Italian Air Force maritime patrol aircraft - not a bad haul for 30 minutes at 2000' on a quite midweek lunchtime in Central Scotland!  I checked that each recorded aircraft was actually in my neck of the woods at the right sort of time using Flight Radar 24, which has given me a lot of confidence that I am looking at broadly the right things. 

They are all 1090MHz though, and I would really like to see some 869MHz contacts.  I was planning to head over towards Balado today to see if I could bag a glider or two out of Portmoak on the re-broadcast system, but the weather beat me.  Maybe later in the week.

I was winging it a bit decoding the TRK file using Excel and a bit of previous experience.  Is there a specification for the file's content that I could get a copy of?

Ancien

Re: External antenna reccomendation?
« Reply #14 on: November 05, 2018, 08:03:44 pm »
David
I have found James Rose's playback really good.
It's on aircrew.co.uk
I hope his new display succeeds.
I fly down south mainly during the week and it is amazing how little traffic is around.
You are doing well for central Scotland!
Cheers.