PilotAware
British Forum => Technical Support => Topic started by: Giver on April 09, 2017, 05:55:26 pm
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Hi Guys
i have just fitted a paws unit to my aircraft and before installing it i had it running fine with my reg showing in traffic and also in sky demon,
decided on a permanent installation so shorten the Aerial leads, made up a permanent cage for the pi micro computer, run power through an 12volt to 5 volt transformer,
it all powers up nicely but it will not show my registration no on Skydemon, other traffic and Mode S shows clearly but in traffic my aircraft is missing,
any ideas?
i have ordered an USB cable to take the GPS signal from the PI direct to my Trig 21 that has just been updated to the latest software available,
The trig 21 is showing coordinate and appears to be working normally,
appreciate any pointers on where to look next,
have included a picture of when it worked last week,
Ivor
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Ivor,
That's correct!
Your aircraft is listed in the PAW Traffic screen as ADSB Out (Mode = CSA - -), with the correct ADSB Data for ADSB driven by a 'non certified' GPS source. The Traffic Screen is only a 'collection box' containing all aircraft 'picked up' by PAW. Being the strongest local signal by virtue of your ADSB Out, your aircraft usually shows at the top of the traffic table. The traffic in this screen is then processed and filtered by PAW, with all ADSB and PAW (P3i) less those filtered (which includes your own aircraft as it does not present a risk), plus the 'highest risk' bearingless target (Mode C or S) being transmitted to your Audio and Navigation Systems. These are then displayed, together with Relative Altitude, plus Aircraft Reg, Flight ID or both Alternating - depending on your chosen Configuration Setting. Your own aircraft automatically shows at the centre of your SkyDemon (or other) Navigation System screen by virtue of your GPS position, but YOUR registration does NOT appear on your own Nav Screen.
Regards
Peter
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peter
thanks for that but how will i show my inspector that it is showing in traffic to get it ok'd by the LAA?
I did turn of mode S filtering assuming it would show then, I also replaced my Hex no with the random generated one, ....... both to no avail
does it mean i will need another PI unit to document what mine is doing?
thanks for your help.
ivor
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Ivor,
Sorry, I didn't realise that's what was worrying you. I obviously misunderstood that your original concern was that your aircraft registration no longer appears on SkyDemon, when you obviously meant 'no longer appears in your 'PilotAware Traffic Display'.
Your Aircraft Reg could only ever have appeared on SkyDemon if your PilotAware was running with a different hex code from your transponder - e.g. the original randomly generated PilotAware Code. This would result in PilotAware seeing your ADSB transmission as a threat and displaying its details (including your Reg) on SkyDemon as a small (probably red) aircraft right on top of your own aircraft symbol at the centre of the screen, which would have explained the initial description you gave.
The screen grab you posted.... 'a picture of when it worked last week,'
...clearly shows that your transponder was transmitting ADSB Out (Mode = CSA - -), and the 3rd and 5th entries in the ADSB Status column of the Traffic Screen clearly indicate that it was transmitting the correct SDA and SIL codes as '0', which are required for ADSB out transmission using a non-certified GPS source, so you must have had your PilotAware connected to the transponder and correctly configured for ADSB transmission at the time that screen grab was taken.
Changing PilotAware to the correct ICAO Hex Code for your aircraft 'later on' to match the one in your transponder, would stop this 'rogue' aircraft (and associated Reg) appearing on your Navigation Screen as it would then be correctly filtered out by PilotAware, though it would normally still show at the top of your Traffic Table. I have to say that although my ADSB Transmission is usually visible at the top of the Traffic Table, it does occasionally disappear and I'm afraid I have no idea why.
It may of course be that there is a fault with your setup or wiring, stopping the data from PAW reaching the transponder. Double-check you have the CORRECT USB port configured for the ADSB out lead to your Transponder (if this is the 'top left' port with the Ethernet port to its immediate left, this is PORT 1) - that you have correctly saved the settings (screen grabs of appropriate screens would help here) and that there is no problem with the connecting cable.
Turning off 'Mode S' by the way doesn't turn off the filtering, it turns Mode S Detection off completely, so that won't help.
With regard to your most recent post....
how will i show my inspector that it is showing in traffic to get it ok'd by the LAA?
does it mean i will need another PI unit to document what mine is doing?
If I recall correctly, the LAA mod procedure actually requires that a separate PilotAware is used to show your ADSB data transmission and in particular the SDA and SIL coding of your installation, (the 3rd and 5th entries in the ADSB Status column of the Traffic Screen), presumably to ensure that the data is genuine. You could show the screen grab which already shows this data, confirms your transmitted Latitude, Longitude and Altitude and is time and date stamped, to your LAA Inspector and ask them if they would accept this as sufficient evidence to support your ADSB Mod application. They may however insist that this is repeated using a separate PilotAware so they can see for themself that the data is genuine before signing off your Mod. In this case you might need to elicit the assistance of another PAW user, which you could do through this forum. Unfortunately Kent is a bit too far away for me I'm afraid, but I know there will be other local users. They do not need to be connected for ADSB Out themselves, just able to provide a screen grab of your aircraft data from their Traffic Screen
Hope this helps clarify the situation. Sorry again for the earlier confusion.
Regards
Peter
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Hi Ivor
I'm based at Southend EGMC if you need another PAW to verify your data....If that's any use to you ??
Brinsley
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Peter,
thank you for your very detailed response, i am renewing my permit this month so will speak to my
inspector about Mod 14 sign off before doing anything else,
regards
ivor
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Brinsley
thank you for your kind offer, I may take you up on it if my LAA inspector won't accept my screen
grabs as proof,
regards
Ivor
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I have experienced exactly the same issue as Ivor since I installed my PAW. Previous threads have covered the problems I had connecting my PAW to my Funke TRT800H, and then the faulty ADS-B dongle, but all is now working fine - apart from the fact that my registration has never appeared on the PAW traffic page. I had concluded that I had to use a second separate PAW to get the screen grab required by the LAA, and have been waiting to bump into someone with a working PAW ever since.
I am almost 100% sure that my transponder is correctly broadcasting ADS-B because every flight I do appears in its entirety on FlightRadar24; prior to ADS-B I'd get only the odd segment when I was high enough for my Mode-S broadcasts to be triangulated.
Is there something within the PAW software that now excludes your own hex code even from the traffic page, thus requiring a separate PAW for the LAA Mod 14 approval?
On a related note, should I disable my ADS-B out until the mod has been signed off? As I know the Funke defaults SDA and SIL to zero, that my tracking on FR24 is accurate and every radar station I have spoken to confirms my outputs as fine I have taken the view that, unless the regs expressly forbid otherwise (which if they do then I haven't yet seen this bit), then I will continue to run ADS-B out because of the safety enhancement it delivers and will get LAA approval just as soon as I can get my traffic page screen grab and convince my inspector to visit.
Best
Stu
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I am not totally sure, but it may exclude your own ICAO code from the traffic screen AND the NAV device.
Can you try changing the ICAO code on the configure page, to something other than your own ID ?
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I am not totally sure, but it may exclude your own ICAO code from the traffic screen AND the NAV device.
Can you try changing the ICAO code on the configure page, to something other than your own ID ?
Good idea; will try on next flight and report back.
Stu
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hi guys
interestingly today i fitted the farnell usb/serial lead to use the GPS mouse, After fitting and changing
a few things in the configure screen i managed to get my registration to show on both Traffic and sky demon,
also on sky demon it showed my Hex no every now and then for about 10 minutes then reverted to not showing in traffic or sky demon, have included some pictures you may find interesting,
Ivor
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picture to show registration,
ivor
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the last one show just my Hex code,
ivor
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hi guys
interestingly today i fitted the farnell usb/serial lead to use the GPS mouse, After fitting and changing
a few things in the configure screen i managed to get my registration to show on both Traffic and sky demon,
also on sky demon it showed my Hex no every now and then for about 10 minutes then reverted to not showing in traffic or sky demon, have included some pictures you may find interesting,
Ivor
Ivor,
Sorry, you have lost me a bit here. Why would you need to fit a Farnell usb/serial lead to use a gps mouse? Or do you mean you fitted the Farnell USB to Serial lead to allow you to use the PilotAware GPS to generate 'ADSB Out' from your transponder. You say 'After fitting and changing a few things in the configure screen i managed to get my registration to show on both Traffic and sky demon.' so I assume you made these changes to your PilotAware setup deliberately to get your Aircraft Registration to show on SkyDemon? If so, you have simply confirmed the point I made to you in an earlier post, that your own aircraft Registration and Altitude can ONLY appear on SkyDemon if you are running the wrong Hex Code in your PilotAware or Transponder or both.
Your Configure Screen clearly shows you were running PilotAware using an Auto-Generated Hex Code (8B6FAB) when it should of course be running the ICAO Hex Code for your aircraft (404416).
Group ID is designed to identify other PAW equipped aircraft who are part of a group. My club might for example use 'EOSM' as our 'Group ID' on a fly-out and all other EOSM group aircraft then show on the Nav Display as for example #G-ABCD#, #G-EDOR#, etc., making them easier to pick out on a busy screen. Otherwise you should leave this set to the default 'PAWGRP', which will rapidly identify any other PilotAware aircraft (if also using 'PAWGRP') by enclosing their callsigns in 'hash' brackets on your display.
With 'Display Traffic Info' set to 'Reg ID' - normally only the 'Reg ID' of other aircraft will be displayed. This is generated by comparing Hex Codes received from other aircraft with PAW's internal database. If for any reason a match cannot be found, PAW will default to displaying the Raw 'HEX ID' instead - which is obviously what happened in your last screen grab.
If you are running a Mode C or S transponder (or ADSB Out via a Mode S transponder), 'Mode CS Detect' MUST be set to 'Mode CS +Filter (Beta)', or PilotAware will see your own transponder's Mode C 'altitude' transmissions as being from a potential threat aircraft - even if you have your Hex Code correctly set.
The SkyDemon screengrabs therefore show your ADSB transmission as a threat aircraft (the small red one) located directly above your own aircraft. The Registration / Hex ID and Relative Altitude are all from that presumed 'Threat Aircraft' NOT your 'own aircraft', due to the fact that you were running the auto generated Hex Code in PAW and were not running the correct Mode CS Filter.
I'm not convinced that this will help convince your inspector that your systems are correctly configured.
A screenshot of your Home and Traffic Pages from today would have helped us to determine what else was going on.
Regards
Peter
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I am not totally sure, but it may exclude your own ICAO code from the traffic screen AND the NAV device.
Can you try changing the ICAO code on the configure page, to something other than your own ID ?
Lee,
I'm currently running the latest public release (version 20170223) in the plane. I don't have any recent Traffic Table screengrabs to show it, but my aircraft was still showing on the Traffic Table last time out - as Ivor's was in his first Traffic screengrab. Both my devices have the same (correct) ICAO Hex. As I said elsewhere, my aircraft does very occasionally disappear from the Traffic Table for some inexplicable reason, but is usually there reliably right at the top with its nice red 'Danger Alert' signal strength box and associated ADSB Data. I wonder if this could be something to do with antenna proximity - i.e. a strong transponder signal swamping the PAW SDR receiver.
Regards
Peter
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Is there something within the PAW software that now excludes your own hex code even from the traffic page, thus requiring a separate PAW for the LAA Mod 14 approval?
On a related note, should I disable my ADS-B out until the mod has been signed off? As I know the Funke defaults SDA and SIL to zero, that my tracking on FR24 is accurate and every radar station I have spoken to confirms my outputs as fine I have taken the view that, unless the regs expressly forbid otherwise (which if they do then I haven't yet seen this bit), then I will continue to run ADS-B out because of the safety enhancement it delivers and will get LAA approval just as soon as I can get my traffic page screen grab and convince my inspector to visit.
Best
Stu
Stu,
See my post above re your aircraft missing from the PAW traffic table.
As per my earlier posts above, unless it has changed since I last looked, the LAA MOD procedure itself requires the use of a separate PilotAware unit outside your aircraft to 'verify' your ADSB output. This is in itself a 'relaxation' from the original approval process, for ADSB Out driven by an 'uncertified' GPS source, which required you to fly a predetermined course across the south east of England agreed in advance with NATS, who would then 'confirm' the output of your ADSB. PilotAware were asked to include the ADSB Status Data in our Traffic Table so PilotAware could be used as an easily available 'across the country' alternative (for which now read 'replacement') way of confirming the accuracy and status of ADSB transmissions to support MOD applications.
WRT your second point, I would personally continue to use your ADSB Out but seek to obtain MOD approval at the earliest opportunity. Your Inspector would normally expect you to have done so by the time you next submit your aircraft for inspection anyway.
Regards
Peter
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Stu,
See my post above re your aircraft missing from the PAW traffic table.
As per my earlier posts above, unless it has changed since I last looked, the LAA MOD procedure itself requires the use of a separate PilotAware unit outside your aircraft to 'verify' your ADSB output. This is in itself a 'relaxation' from the original approval process, for ADSB Out driven by an 'uncertified' GPS source, which required you to fly a predetermined course across the south east of England agreed in advance with NATS, who would then 'confirm' the output of your ADSB. PilotAware were asked to include the ADSB Status Data in our Traffic Table so PilotAware could be used as an easily available 'across the country' alternative (for which now read 'replacement') way of confirming the accuracy and status of ADSB transmissions to support MOD applications.
WRT your second point, I would personally continue to use your ADSB Out but seek to obtain MOD approval at the earliest opportunity. Your Inspector would normally expect you to have done so by the time you next submit your aircraft for inspection anyway.
Regards
Peter
Many thanks Peter, once again. I suspect you may also be right about the transponder signal swamping the PAW antenna; they are very close.
Best
Stu
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Peter,
I put in all my correct information as you suggested and my aircraft is now missing in traffic and shows only as a aircraft in Sky Demon,
it is picking up other Mode S so all seems to be OK, i probably will need another PAWs unit to verify to my inspector that's mine is functioning correctly,
thank you for your input it's been very helpful,
two current screen grabs,
Ivor
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second screen grab
Ivor
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Thanks Ivor,
As I have said previously, that is the way it is designed to work. I can't say why your aircraft isn't appearing in the Traffic Table, except as surmised above. I clearly remember discussions with Lee about software changes to implement the filters when we were developing the Mode S and Audio Out functions and am certainly not aware of any software changes which would cause your aircraft not to appear in the Traffic Table. Mine still shows my own aircraft and I'm using the same software version in the plane that you have.
I have just re-read both the LAA and BMAA MOD procedures, both of which require the use of a separate PilotAware located away from the aircraft and observed by the Inspector to verify the ADSB Output. Speak to your Inspector and perhaps Brinsley or someone else local can help.
Let me know how you get on.
Regards
Peter
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I went flying today and the flight recorded perfectly on FlightRadar 24; see attached screen grab. This suggests that ADS-B out is working fine.
When I landed I managed to get a screen grab of my registration (G-UIRO) via a second PAW, separate to the one in my gyrocopter ; but this seems to show it as a PAW transmission and does not seem to recognise the ADS-B output - again see screen grab.
Peter I tried your suggestion of amending my hex code and registration in my own PAW but I still could not get it to appear on my own PAW traffic page.
I'm confused as to how to get a compliant screen grab so as to submit to the LAA as Mod 14. It seems, from FR24 at least, that my ADS-B out is working fine, but my own PAW refuses to ever show my registration on the traffic page and a separate PAW defaults to only recording my PAW transmission and ignores any possible ADS-B output.
Best regards
Stu
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BTW, in case anyone is wondering, the white segments of my FR24 tracks are where I went really low (below 10 feet) over the sand - the wonders of gyrocopter flying in this part of the world ;D
Stu
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sorry to be a party pooper but to know from FR24 that your ADSB is working you need to click on your aircraft and check that it is not just tracking you by multilateration of your ModeS transmisions.
Alan
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Hi Stu,
Just back in from a day's childminding. Thanks for the update and screen grabs. I had it in the back of my mind that the FR24 tracks you reported previously could be from your Mode S via Multilateration as Alan has suggested and was thinking this again as I was reading your update. You would need to check by clicking on your aircraft and seeing what FR24 is reporting you as. If this was the case, however I would still have expected PilotAware to report your aircraft as Mode CS--P, though you might not of course have Mode C/S detection enabled in PAW. Are you aware that Mode C/S Detection is DISABLED by default to avoid confusing inexperienced users and must be enabled in the configure screen - normally by selecting 'Mode CS +Filter (Beta)' in the Mode CS Detect box, together with an appropriate 'Relative Altitude' and 'Range' setting. Perhaps you could confirm what Mode C/S settings are set in 'PAW Configure'. If Mode C/S is still disabled, I would suspect your aircraft is not transmitting ADSB, which we can then investigate.
Regards
Peter
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Hi Peter and Alan
Attached is a screen grab of exactly the same flight flown a few months back before I had PAW and therefore without ADS-B out; it's a pure Mode S track via MLAT. You'll see that I appear only very briefly. This is how all my flights appeared prior to enabling ADS-B out, which is as I expected because in the gyro I fly low (nearly always below 1,000 feet), whilst MLAT requires at least 3,000 feet. Once I enabled ADS-B out, all my flights appeared on FR24 in almost their entirety, with only the very, very low level bits missing, which is entirely as I would expect.
FR24's help pages describe MLAT triangulation as follows:-
'MLAT
In some regions with coverage from several FR24-receivers we also calculate positions of non-ADS-B equipped aircraft with the help of Multilateration (MLAT), by using a method known as Time Difference of Arrival (TDOA). By measuring the the time it takes to receive the signal from aircraft with an older ModeS-transponder, it's possible to calculate the position of these aircraft. Four FR24-receivers or more, receiving signals from the same aircraft, are needed to make MLAT work. MLAT coverage can only be achieved above about 3,000-10,000 feet as the probability that four or more receivers can receive the transponder signal increases with increased altitude.
Most parts of Europe and North America are today covered with MLAT above about 3,000-10,000 feet. There is also some MLAT coverage in Mexico, Brazil, South Africa, India, China, Japan, Taiwan, Thailand, Malaysia, Indonesia, Australia and New Zealand. More areas will get MLAT coverage as we continue to add new receivers to our network.'
My configuration settings are also attached in a screen grab.
After enabling ADS-B out I asked Hawarden, Liverpool and Shawbury to confirm ADS-B receiving OK. Although none of them specifically said 'yes, we can see your ADS-B', they all said that the transmission was loud and clear. It all points to ADS-B out working fine, but I just can't get the second PAW proof for the LAA. Might there have been a software change that now excludes own transponder from even the traffic page, never mind the feed to SkyDemon etc?
In all other respects PAW seems to be working fine. My flight yesterday took me past a major incident where there were two air ambulances and a police helicopter; I got traffic alerts for all three even though I was visual from miles out. I could also see the ADS-B CAT and GA.
Best
Stu
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Hi Stu
Where are you based - apologies if already asked, cannot find this in the thread
Thx
Lee
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Hi Lee
I fly gyro (complete with PAW) out of Ashcroft and C182 (not yet fitted with PAW) out of Liverpool.
Best
Stu
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Stu,
I'm extremely confused by these ongoing ADSB issues. As I said in an earlier post above, I can think of no reason why the software would exclude 'own transponder' (ADSB) from the Traffic Table as the filters have always been applied after the Traffic Table and Lee specifically adjusted PilotAware some time ago at the request of FASVIG to allow PilotAware to become the accepted method of confirming the status of non-certified GPS ADSB transmissions for MOD approval. I'm also pretty sure mine was still showing at the top of the Traffic Table when I looked last weekend or the weekend before and I have been using the current version of the Public Software Release 20170223 in the plane since it came out, except when testing any new developments.
I was flying today, but with a young ATC Cadet in the back seat on only his second flight and having to negotiate bad weather and a prolonged hold while transiting the Edinburgh Overhead, I'm afraid checking my Traffic Table slipped my mind. I will however try to get back down tomorrow and check this specifically - even if as seems likely, the wind precludes actually doing so in the air.
Bear with me,
Regards
Peter
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Total wild card, but could it make a difference if the transponder is, or is not being interrogated by the radar head.
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Ian,
If the transponder isn't being interrogated, it will not transmit a Mode S response, but ADSB is completely independent of Radar interrogations and transmits automatically.
I'm going to head back down to the airfield this afternoon to carry out some further tests and will report back later.
Peter
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Ian - I thought this too, but as Peter says my understanding is that the TRT800H squits (lovely word :P) ADS-B data even when not being interrogated. In any case, the interrogation symbol was flashing.
Peter - please do not make a specific trip on my account! It's the Easter weekend and I'm sure you have better things to do.
As ever chaps, I really appreciate your help, and have every confidence that we'll get to the bottom of this. In case any of this is relevant, some additional info:-
1. I am now running PAW purely from a dedicated Anker 20100 battery pack to eliminate any possibility of spikes from the 12v socket. I have been doing this for the past few weeks, with a fully-charged pack each flight.
2. The nose cone of my gyrocopter is definitely GRP, not carbon fibre. A pic is attached of the interior showing my multiple aerials, with PAW on the left wall and trimmed-to-size 1090MHz in front of the VHF radio aerial. The plate and ground plane on which the VHF aerial sits has the transponder aerial on the underside beneath the nose cone. I did wonder if the ground plane was perhaps shielding the 1090MHz aerial from line of sight of the transponder, but this wouldn't explain why the second, external PAW reported only PAW and not ADS-B.
3. Both my PAW and the second external one had the default Group ID of 'PAWGRP'; might this be relevant?
4. For the past month or so I have been getting really bad static on certain comms channels, typically between 123 and 128 MHz; it took almost maximum squelch to silence. All radio units reported readability 5 and confirmed that the noise was not being transmitted. I finally figured out the culprit on my last flight - my expensive, and supposedly VHF-suppressed LED landing lights, as visible in the pic. If I turn them off the noise disappears; with them on it is very audible on certain channels. But this only started recently, around the time I installed PAW. I originally thought that I might be getting noise on the external input carrying the PAW audio to my ATR833 radio/intercom, so bought the ground loop isolator which improved matters for a while. Very strange; perhaps simply down to the physical closeness of all the aerials and LEDs within a confined space.
All the best
Stu
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Peter - please do not make a specific trip on my account! It's the Easter weekend and I'm sure you have better things to do.
...than go flying?! :o
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I'm going to head back down to the airfield this afternoon to carry out some further tests and will report back later.
It was the testing bit that troubled me; flying is entirely acceptable ;D
Stu
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Hi peter
just tried my paws at the workshop and for about 10 minutes it was showing my Registration so have taken a couple of screen grabs fo my inspector,
regards
Ivor
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All looks good,
Peter
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Just back from a test flight which was less successful than Ivor's - at no time did my registration appear on the traffic page.
In fact I seem to have a fundamental problem with either my PAW or my installation. After take-off the interference on certain radio channels was worse than ever; I could not understand the transmissions. This time the interference did not go when I turned off the landing lights. I went through a process of turning of all my electricals - iPad charging, electric fuel pump, strobes - no difference; until I unplugged the PAW, whereupon the interference disappeared immediately. The PAW was running from an Anker 20100 power brick, as recommended.
For now, and with great disappointment, I have had to disable both the PAW and therefore my ADS-B out; the radio problems are simply too distracting.
At the moment I don't know whether I have a faulty PAW (my ADS-B dongle was definitely faulty; might this be symptomatic of a generally dud unit?), a problem with the location of my installation (although there aren't many options in an open-cockpit gyrocopter!) or perhaps a grounding problem. The latter is not something I know much about but I will do some research.
Stu
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BTW, in case it is helpful, attached is a pic of today's flight. Note the sudden cessation, which is at exactly the point I disabled PAW and therefore the GPS input into my transponder for ADS-B out. Once the transponder dropped to standard Mode S, I was invisible to FR24.
So I have absolutely no doubt that my ADS-B out was working fine; just unfortunate that something in my PAW installation is causing such bad RF interference.
Stu
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Hi Guys,
Just back from the airfield. Lovely sunny day, but wind unfortunately 21G31KTS, so flying not an option. Powered up my PAW (in the hangar - not hanging onto the wing in that wind ) :( and then powered up transponder - ADSB Out reported on my PAW as normal. It is then filtered by the software to prevent it being sent to Audio Alerts or Nav System.
Got mate to power up his PAW (also in the hangar) - shows up on my traffic screen (and Nav Screen) as a danger alert with associated audio warning.
He then turned on his ADSB Out Transponder and the PAW Traffic Screen for him changed to ADSB with warnings on Nav System and Audio Alert.
So all working as expected and definitely NOT a PAW software issue. Screengrabs attached (Lack of other aircraft due to metal hangar)
Regards
Peter
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Thanks Peter; conclusive proof that I have either a dodgy PAW or something not right in my installation. I have never seen my Reg on the traffic page, but am 99.9% sure that my ADS-B out was working fine.
Best
Stu
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Stu,
Sorry to hear about your ongoing interference problems this afternoon.
Before hearing about this, I was looking at the pics of your installation at the airfield earlier in the day with a colleague who works in data and radio transmission and we were both extremely concerned about the close proximity of your VHF and PilotAware antennas to your 1090MHz Mode S / ADSB transponder antenna. This is almost certainly the source of your problems. The transponder transmits short but very high power pulses relative to any of your other equipment (in the region of 100 Watts output at the antenna). At such close range such strong transmissions will at best significantly desensitise (deafen) PAWS 1090MHz SDR receiver and could possibly even cause it some damage. The 'short but powerful' data pulses will almost certainly also have a detrimental effect on your VHF comms receiver, again desensitising it and presenting as loud clicks, white noise or other similar interference and requiring a higher than normal squelch level to mask them - as you have reported. I appreciate that in an open cockpit aircraft antenna positioning is difficult, but I really think you need to increase the separation between your transponder antenna and the rest of your antennas.
Regards
Peter
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Hi Peter
I suspect you may well be right. The transponder and radio together with associated antennas were all installed by the aircraft manufacturer. I had no problems with the radio before I installed PAW, so although the transponder and VHF antennas are physically closer than ideal they do seem to work as long as PAW isn't also in the mix; perhaps the significant difference between the comms frequencies and the 1090MHz transponder frequency is the reason.
I have already tried moving the antennas further away; I have the centre-fed dipole but its 10-foot cable wasn't quite long enough for the only other viable mounting option, the front of the rotor mast (accepting that this would give hardly any rearwards transmission; I was relying on my ADS-B out to cover this). I have also cut the 1090MHZ antenna to half length but it is still too long to fit between my instrument binnacle and screen. I will have to try a different approach, although at this point I really can't think of many alternative mounting positions.
May I suggest that the PAW manuals be updated to include guidance about ensuring separation between them and any transponder antennas; unless I have missed it I don't think there is currently any mention of such, although there is detailed advice about situating away from people and metal! The manuals also imply that any radio interference is almost certainly down to power supply, whereas it seems that the transponder issue may be another cause.
I just hope that we've discovered this in time before my PAW has been fried due to signal overload!
Best regards
Stu
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Hi Stu,
Could you please try some experiments next time you get the chance.
I would like you to remove some of the dongles individually (when PilotAware is up and running) to see if they contribute to the noise, please try the following in exact order and let me know what happens
1. Remove RTL-SDR (ADS-B) dongle
(wait 20 seconds)
2. Replace RTL-SDR (ADS-B) dongle
(wait 20 seconds)
3. Remove GPS-Dongle
(wait 20 seconds)
4. Replace GPS-Dongle
(wait 20 seconds)
5. Remove USB/RS232 to Transponder
(wait 20 seconds)
6. Replace USB/RS232 to Transponder
(wait 20 seconds)
7. Remove WiFi Dongle
(wait 20 seconds)
8. Replace WiFi Dongle
(wait 20 seconds)
Remove Power
Connect Power
Please let me know what effect each of these has at each stage.
The RTL-SDR, GPS and USB/RS232 are hot-pluggable, so will recover automatically when re-inserted.
The WiFi is not hot-pluggable, and hence should be the last item to be removed in the list
Thx
Lee
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Can you borrow another battery to try? It's not unknown that some examples of battery units can produce RF noise. The units use a boost converter to get the 3.2-4.2V of the lithium battery up to 5V. Usually not a problem with RF on Anker, but individual units may be slightly faulty in this regard.
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Hi Lee & Paul
I will do as you suggest; I have the GPS mouse rather than the dongle; and I will use a different Anker 20100 power bank (I have two).
TBH I suspect Peter's assessment is correct, and that things are not going to improve unless and until I can find somewhere else to site my antennas. I really don't think power is the problem; I get the same issue whether I run from the recommended Anker power bank or 12v socket adapter.
As the problem seems to have got progressively worse, I just hope that I haven't already fried my PAW.
Best
Stu
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Stu,
The (UHF) transponder will have much less effect on the (VHF) Comms Radio, than on the 1090MHz PAW SDR, though it could still desensitise it. I wouldn't be too worried about the PAW bridge as itshould be far enough off frequency not to get fried, though it might go a bit deaf during Mode S or ADSB pulses unless you can move the antenna. (You could use extension cables by the way, but try to keep them as short as possible.) You will soon know if the SDR is still working or not.
I am interested to hear the results of the tests Lee has asked you to do.
I agree with Paul's comments about battery power packs. I have experience of several non-'Anker' packs which either won't work at all or cause PAW to generate loads of interference. Our FI also tried to power up his brand new PAW with one of the newer 'intelligent' 21,000 size Anker packs recently, which flatly refused to recognise the load and wouldn't start it, so its definitely worth trying both of your packs - other users please note!
Regards
Peter
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An interesting day, with mixed, and rather confusing, results.
Lee, I went through your steps but I wouldn't say any one made a bigger difference than any other; apart from the power, which returned the radio to normal.
I then moved both aerials so that they are now at least three feet from my transponder aerial; they are tucked inside the seat frame, one either side, and slightly forward of my body. This may not sound ideal, but it (eventually) seems to have worked - see the attached 'Traffic' pic; 169 aircraft received whilst airborne! This is way more than I ever saw before. I say 'eventually' because I only saw this massive increase in the number of aircraft received after I also swapped out my 1090 MHz aerial for the one that came with the replacement ADS-B dongle I bought to replace my originally faulty one; I would say this new aerial received perhaps 10 times as many aircraft when sited in the same, new position. I also cut it down to size (half-length). Both my original aerial and dongle therefore appear to have been faulty.
In flight I saw way more traffic than I had ever seen before. And I also started getting very many audio and visual Mode S alerts; so many that I had to silence the audio. It was only when I landed that I realised this was most likely because I had the settings wide open; see' Config' pic attached. I had to do this with my old set-up in order to receive any traffic. I will now close the filters down a little.
And the best news of all... no radio interference; all crystal clear. Whilst I was also using my second Anker 20100 Power Core, I think it way more likely that the noise issue was resolved by moving the aerials - so Peter it looks like you were right.
So that's all the good news. The less good news is that I still can't get my own registration to appear on the traffic list. I know I am broadcasting ADS-B out; see 'FR24' pic of today's flight as attached, and note that I definitely would not have posted such a clear trace at my low altitude under Mode-S MLAT. I don't understand what's going on with this, but just to add one more weird issue into the mix, on landing I cycled through my transponder's settings and you'll see in the 'TRT800H' pic that the position field reports 'wrong data'. It has never said this before. The Funke manual says that this means no valid position is being received; it would show 'no data' if no position information was received. But the PAW GPS fix was strong, the NMEA and baud settings are correct; and the FR24 track is perfect.
Any ideas?
Stu
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Great news, and thanks for reporting back.
I had one of those antenna faulty out of the box as well. Used the cable to make my own mini-dipole for ADSB. I am guessing it is the cable to whip connection, though the method of trapping the screen is also dubious.
Sorry Cannot help with transponder, don't even have one.... yet
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Stu,
Glad to hear things are now working. Keith / Lee will no doubt pick up the comments re antenna location well clear of Transponder / ADSB antennas and update the Antenna and Installation Guides.
Still don't know what is going on with your transponder! I'm not experienced with FUNKE as I use Trig. Remind me what USB to RS232 lead you are using. This might be the problem. Might also be worth an e-mail to FUNKE suport to ask what would cause such a message.
Don't despair - things are getting better!! ;) :)
Regards
Peter
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Had a think about RS232 signals in general
As Flight Radar confirms ADSB out rather than MLAT? there must be RS232 messages from the PAW, which are received and decoded by the transponder. There could be two things to that can cause issues, which may lead to that error message on screen:
1. The Baud rate is too slow and the message is truncated
2. There is a section in the sent message that is incorrectly formatted, or not supported by the transponder.
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Hi Peter and Ian
I am using the recommended USB-RS232 lead as here http://uk.farnell.com/ftdi/usb-rs232-we-1800-bt-0-0/cable-usb-a-rs232-serial-convertor/dp/1686450
It's the same one I have always used, and I have never seen the 'wrong data' message before; and I have checked several times previously to make sure all is OK. The PAW is configured for Funke on USB port 1 at 4800 baud, and the transponder to receive NMEA at 4800; all as before, and as the PAW and Funke manuals recommend.
The fact that my FR24 tracks are now complete and accurate is pretty convincing proof that my ADS-B out registration, altitude and position data are all fine. But I cannot understand why I don't appear on my PAW's traffic page and why the transponder is now saying 'wrong data'.
Can I please ask a question of anyone else with the same USB-RS232 lead - what colour does the light on the USB end flash in normal use? I don't remember seeing it previously, but it is currently flashing red when in use; and in general a red flashing light is not a good thing. I can't find colour codes listed in the lead's manual.
Best
Stu
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I think Funke have to comment on what this means.
It could mean anything from an unexpected/unhandled NMEA GPS message
to a CRC failure on the message itself.
It is impossible to guess.
What we could do, is capture the messages sent to the transponder (using the logging facility) and give this to Funke to see which of the messages are causing them to produce this error
Thx
Lee
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Hi Lee
I've asked Funke and am awaiting their reply.
How do I use the logging facility? Does it need to be enabled before flight?
Best
Stu
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How do I use the logging facility? Does it need to be enabled before flight?
http://www.pilotaware.com/documents/
Latest Operating Instructions
Page 33, check the 'trp' field, this should log the messages sent to the transponder
Thx
Lee
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I think Funke have to comment on what this means.
It could mean anything from an unexpected/unhandled NMEA GPS message
to a CRC failure on the message itself.
Funke have replied as follows:-
'What data sets do you send to the TRT800H? As mentioned in the manual it expects RMC'.
Does this mean anything to anyone? All I have done on the PAW side is set USB1 to 'Transponder Funke' at baud rate 4800.
Stu
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In answer to the question Sdkeller posed on initial startup the USB cable flashes onceGreen and after 30 seconds starts to pulse red every 10 seconds or so,
In traffic my aircraft didn't appear this time but i am certain it's all working fine, I am in a metal roof workshop surrounded by buildings but still receiving plenty of returns,
Ivor
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In answer to the question Sdkeller posed on initial startup the USB cable flashes onceGreen and after 30 seconds starts to pulse red every 10 seconds or so,
In traffic my aircraft didn't appear this time but i am certain it's all working fine, I am in a metal roof workshop surrounded by buildings but still receiving plenty of returns,
Ivor
Thanks Ivor; that's exactly what my cable does. Interesting that you seem to have intermittent listing of your own registration on your traffic page; mine has never appeared whilst others report that their registrations always appear. I wonder what could be different between the various installations to cause these different outcomes?
Stu
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I think Funke have to comment on what this means.
It could mean anything from an unexpected/unhandled NMEA GPS message
to a CRC failure on the message itself.
Funke have replied as follows:-
'What data sets do you send to the TRT800H? As mentioned in the manual it expects RMC'.
Does this mean anything to anyone? All I have done on the PAW side is set USB1 to 'Transponder Funke' at baud rate 4800.
Stu
I am fairly confident that the issue is not with your RS232 cable, or you would get no ADSB out, which we know is working.
To answer your question above:
According to FUNKE, the transponder is looking only for RMC messages, which look like this
$GPRMC,170956,A,5155.866,N,00126.196,W,0.000,0,060816,,,A*7EIf there is a formatting error in this message by PAW, it could trigger the error you get, or it could be that PAW unit is also sending out anther messages like GSA, to which the transponder is objecting. I suspect the later. This is why Lee wants you to enable logging.
Cheers
Ian
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Thanks Ian. I am hoping to fly tomorrow so will enable logging and report back.
Stu
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Hi Stu,
Just to let you know I am still here. I'm just keeping a 'watching brief' at the moment as data messages are much more Lee's area than mine. I was using the same FTDI lead and tried to check the lights for you down at the plane yesterday, then realised I had swapped my FTDI lead to the CFI's plane when I did his PAW/PowerFLARM installation and am still running a different style temporary lead on my own plane just now. Up to my eyes in bits unfortunately in the middle of a 500 hour wing strip. The joys of (not) flying!! Ah well - back to the airfield, it won't rebuild itself!
Regards
Peter
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Hi guys
Log attached. Looks like Ian and Lee are right. Have tried rebooting PAW; transponder still reporting 'wrong data'.
Just off flying. If you can give me some pointers I can try and make changes for the return flight.
Cheers
Stu
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If you can give me some pointers I can try and make changes for the return flight.
Hi Stu
I think we need to forward this to Funke.
These are standard NMEA Messages.
If you connected a GPS Source directly to the Transponder - this is what you get.
So I think we need to ask Funke what they are objecting to, in order to generate the message "Wrong Data"
Funke should be capable of discarding the messages that it does not require - maybe this message is superfluous.
Thx
Lee
(Update: I have emailed Funke, lets see if I get a reply)
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Thanks Lee; I misinterpreted and thought there was too much there in the log.
Got a worse problem though - had to disconnect PAW midway as radio interference was terrible again; interference disappeared as soon as PAW power was cut.
And had a close encounter with a drone @ 1500 feet just south of Manchester zone.
Cheers
Stu
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Radio Interference.
Something is not right here, you should not be getting this.
Can I ask what the interference is ?
is it a white noise effect, or a click ?
What I have seen is the following
If the RF antenna of PAW is close to the VHF antenna, you may hear a click every 1.6 - 1.8 seconds
If there is an issue with power, you can get a white noise effect over the RF
If this is persisting, we need to send a new unit to see if this solves the problem, and we can analyse you unit.
If it repeats with a new unit this would indicate power (if white noise)
But I recall you said you had changed power supplies to see if this was the issue
Thx
Lee
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Check the ground (GND) connection on the USB-Serial cable is still physically connected, it could be the lack of a signal ground is impacting the serial comms and potentially creating issues with noise too. That could explain both issues.
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USB to transponder ground is definitely still firmly connected.
It's a white noise, only on certain frequencies. Today, Manchester approach was fine; Doncaster Radar completely unreadable - even squelch 9 wouldn't clear the noise. Until I disconnected PAW.
Flew back without PAW connected and radio was fine throughout, across all frequencies; squelch 2 was sufficient (squelch 1 is fully open).
Today I was back to my original Anker 20100 power core.
Best
Stu
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Back home now.
With apologies for hijacking Ivor's thread, I thought it would be helpful to summarise my experience with PAW to date in one place so that those who understand these things better than me can make an informed diagnosis.
1. Prior to installation of PAW, I had no radio interference problems.
2. On installing PAW, I initially received hardly any traffic and started noticing radio interference problems. Eventually diagnosed both a faulty ADS-B dongle and aerial.
3. As we suspected closeness of the antennas to the transponder aerial may have been the cause of the interference, I have moved my PAW and 1090 MHz aerials away from their original locations and they are now at least 3 feet from the transponder antenna, as recommended in my Funke TRT800H manual.
4. The PAW itself remains physically quite close to my radio unit, but I suspect others will have similar installations and my options are limited!
5. On the first flight after moving the antennas, there was no interference. However, it has always been intermittent and present on some frequencies whilst clear on others.
6. On today's flight my base safety com 135.475 was clear, as was Manchester 118.575; Doncaster 126.225 was unreadable due to noise. Previously I have had unreadable levels of interference on Hawarden 123.350, Liverpool 119.850 and Welshpool 128.000.
7. When present, the noise is white noise of a very high level and cannot be squelched out. It disappears when unplugging the PAW.
8. I have run the PAW from two different Anker 20100 power cores as well as the recommended Anker 12v adapter and have experienced the same radio interference problems through all.
9. With my new ADS-B dongle and new 1090MHz antenna in their new positions, I am receiving loads of traffic - see pic attached of today's screen grab; 246 aircraft being received! My traffic volumes have increased perhaps ten-fold since I used the new 1090MHZ aerial.
10. Despite using the recommended USB-RS232 lead connected to my Funke TRT800H, I have never seen my aircraft appear on the traffic page of PAW.
11. Funke have not been very helpful throughout the process. Their instructions say to wire the 'brown' cable from the TRT800H wiring to the data out from the RS232 cable (orange); but there are two browns - see pic attached. They refused to confirm which one, saying they could not comment on my installation; by a process of elimination I connected as shown. As for the grounds, again I have had to assume, by a process of elimination, that the bare cable visible in the pic is the ground.
12. With the transponder wired as per the pic, I have been achieving ADS-B out successfully for a month. I know this because my FR24 tracks have been transformed and now appear in their entirety. For example, see pic attached of today's flight - I had to pull the PAW power just before the Ladybower Reservoir, once I'd switched from Manchester to Doncaster and the unreadable interference; my trace disappears immediately. Although I continued to Netherthorpe and back to Ashcroft on Mode S, without ADS-B, having lost the PAW GPS input, I was invisible to Flight Radar. So it looks like ADS-B has worked fine, but I've never appeared on the PAW traffic page.
13. I note that Ivor intermittently appears on his traffic page.
14. I love what this product is trying to achieve, and can see for some that it works brilliantly. For me, the ADS-B out functionality is a key point and I'm sad to have lost it. Outwards visibility from a gyrocopter is superb, but we are hard to spot from other aircraft and I want to be as visible as possible.
15. I suspect that (a) I have a faulty unit, (b) I have somehow wired my PAW-transponder incorrectly (but ADS-B out was working fine even today, despite the 'wrong data' message) or (c) there is some grounding issue affecting my radio (but all problems go when PAW is disconnected and there was no problem before PAW installation).
I have returned home with my disconnected PAW module, leaving the antennas in the aircraft.
Many thanks, once again.
Stu
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It's gone very quiet on here.
Lee, do I need to return my PAW unit to you,and if so, to which address?
Best
Stu
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Hi Stu,
Sorry, I've been at the airfield the last 3 days from 8 am to after dark doing a 500 hour 'wing strip' service on my aircraft ready for permit inspection, hence my 'absence' from the Forum. By the time I got home each night I could just about manage to crawl up to bed (my hips and knees definitely don't like crawling about on a hangar floor these days) so haven't managed on here much.
I don't know if Lee wants you to send your unit back to Dave at PilotAware Hardware, or if he wants you to sent it to himself. He will probably PM you with a return address once he sees this.
Regards
Peter
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Hi Stu,
I have asked Dave Styles to contact you for a return, and at the same time get a new unit out to you, to see if this resolves the Radio issue.
I will PM my cell number, just so we can fully understand the installation, easier than email sometimes
Thx
Lee
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Thanks Peter and Lee; I really appreciate all your help. Peter - sounds like you are having a way tougher time than me! Hope you get flying again soon. Lee, great to chat before.
Best
Stu