PilotAware
British Forum => General Discussion => Topic started by: Easy Cruising on September 17, 2018, 04:50:17 pm
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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.
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Installation kits any help ?
https://pilotaware.com/products/
https://pilotaware.com/product-category/installation-kits/
Thx
Lee
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Thanks Lee. I was hoping not to have to buy a whole kit just to get 1 antenna, hence asking about ebay/amazon.
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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
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Thanks exfire.
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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 (https://www.facebook.com/photo.php?fbid=10213888559960471&set=a.1121865299156&type=3)
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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.
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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
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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
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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?
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I think that it is two distinct aerials in a single assembly. Each has its own individual feeder.
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An interesting option, David,
Please keep us posted on perceived performance as you gain further experience of the antenna ‘in flight’.
Regards
Peter
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Will do.
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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?
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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.
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David,
Unfortunately you won’t get any 869 rebroadcast up here in Scotland at the moment. The only rebroadcast station in Scotland to date is my station at Balerno (West Edinburgh) which has been active for the last 15 months, but is currently ‘down’ while I reorganise a more permanent power supply and antennas. Plenty of PAW Traffic most weekends out of East Fortune though if you are through our way. Nearest FLARM rebroadcast is Milfield if their gliders are active.
Best Regards
Peter
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Thanks for the replies - really useful info. Next time we get some decent weather at the weekend I’ll head east-ish and see if I can bag some 869MHz traffic.
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David,
I should have said, there is a plan to expand OGN-R coverage up here and I’ve already got approval to install at several sites, but it’s a bit of an uphill struggle trying to find the time to get things moving (mainly due to conflicting time demands at home :( ). Planning and gathering the necessary bits is however proceeding apace and I hope, to get things back on track shortly.
Regards
Peter
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I’m happy to do a bit of the leg-work if I can be of any help ease the load a bit. (32 years as a NATS Engineer)
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Peter
Sign David up before he changes his mind :P
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Second PAW flight for India Delta today. A few observations:
1. The external antennae arrangement seems to be working well - 44 contacts today in 30 minutes at 1500'.
2. My first traffic alert, with an 870MHz Sports Cruiser 12 o'clock, 400' above. Seen well outside 9km on the SD screen. Reported and tracked sensibly throughout.
3. The aircraft is also Cumbernauld-based and re-appeared as traffic on the way back to the airfield.
4. I spoke to the pilot and he had seen our second meeting on PAW, but not our first. I am using ADS-B OUT, so perhaps my engine was masking transmission from my belly antenna.
5. In the .TRK file, his callsign sometimes appears as his registration, sometimes as his registration bracketed by '#' characters. Is there any significance to this?
6. Only other item of note is that ICAO 24-bit addresses 400613 and 400E13 were in the vicinity at the time and they have got muddled on occasion - they only differ by a single bit. I'm not particularly bothered, one is a BA 747, the other an EZY Airbus.
I was very impressed by the traffic alerting - it was ages before I spotted the aircraft visually even though I knew exactly where to look.
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Hi David,
Excellent feedback! I’ll let Lee reply on the technical points as I’m just about to head off down to the airfield to see if I can get the OGN-R up and running.
I will call you later.
Regards
Peter
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Final post from me on this subject....
I've flown a couple more times over the past few days.
30 minutes last Monday yielded 43 tracks. 50 minutes today 63.
Last Monday I got a traffic alert on an airliner 4km/2000' above - he was inside CAS, I was outside.
Today I got a traffic alert on another Cumbernauld-based light aircraft.
I have now seen and been alerted to traffic on both 1090MHz and 870Mhz.
I am delighted with the antenna's sensitivity. It is exceeding my expectations.
Incidentally, I believe that it is two half-wave dipoles mounted in a common body. Although it is mounted on a metal panel, there is no physical connection to it (unlike, say a TED) so it is not a quarter-wave unipole.
As I taxied in today, I received another traffic alert - '8 o'clock, same level, 240 metres'. The icon appeared on the apron at Cumbernauld, labelled 'Undefined'. After I shut down I went to investigate. It may have been another light aircraft moving away from the fuel pump. Looking through the .TRK file, the only candidate ICAO address is C13C3E which is, well.... undefined!
I am enjoying the post-flight 'plane-spotting', but I expect the novelty will soon wear off. ;-D