Author Topic: Polar diagram shows no activity with PilotAware  (Read 679 times)

crisisguy

Polar diagram shows no activity with PilotAware
« on: December 25, 2021, 12:41:34 pm »
just checking with the vector feature

I get good coverage on all 4 quadrants with adsb but with pilotare selected its shows nothing.

I have an external aerial located on the belly of the aircraft

whilst flying, the webbrowser page showing the functionality of the pilotaware unit is all green

am i doing something wrong?
« Last Edit: December 30, 2021, 05:47:36 pm by exfirepro »

exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #1 on: December 25, 2021, 01:43:12 pm »
Hi CG,

Happy Christmas.

Initial thoughts -

What is your Reg / ICAO Hex? (I can take a look on our database and see what has been reported).

Are you sure you have the correct Hex ID configured in your PilotAware? If you haven’t, it will report on Vector using its default (MAC derived) Hex rather than the one for your aircraft.

To get a good report on the lower-power frequencies / modes, you need to fly for a reasonable period within receive range of a number of ATOM-GRID Ground Stations. If you are too far away, they won’t report you. Can you give an idea of where you were flying (or I can probably work it out from the database with your ICAO and PAW Hex).

Screenshots of your PAW Home and Configure Screens would be useful to confirm settings.

Best Regards
Peter

Edit: I did post most of the above earlier, but it was chopped in transmisssion and only the first two lines appeared
« Last Edit: December 30, 2021, 05:47:15 pm by exfirepro »

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #2 on: December 27, 2021, 10:31:35 am »
thxs Peter for festive response!

Reg is G-CILG

Hex code im using from the G-INFO database is 406C84. I remember inputting this when first setting up the PA however that was a few years ago and ive updated to the rosetta since

Last flight i made was 22/12/21 - it does show this flight

Ill take screen shots of configuration when i next fly
« Last Edit: December 30, 2021, 05:46:43 pm by exfirepro »

exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #3 on: December 30, 2021, 06:15:04 pm »
Hi again CG,

Thanks for the update.

I have checked the PAW database which shows several hundred separate ADSB-Out reports from 406C84 from PilotAware ATOM Ground Stations between 26th February 2021 up to and including your flight on 22nd December 2021 (that flight alone is reported from 29 distinct ATOM Ground Stations), yet I can find no reports whatever from PilotAware Transmissions from the same Hex ID during this period.

This could of course indicate a fault with your P3i transmitter or antenna, but I think it more likely that for some reason your Rosetta was either incorrectly configured, or has somehow reverted to it's default Hex ID (which is the last 6 digits of the unit's MAC address). If you can't get to the plane, you should be able to determine this 'default' Hex ID from your licensing paperwork. If you can let me know (message me if you don't want to make it public), I can recheck the PAW database for you using the 'default' Hex ID.

Best Regards
Peter
« Last Edit: December 30, 2021, 06:17:56 pm by exfirepro »

JCurtis

Re: Polar diagram shows no activity with PilotAware
« Reply #4 on: December 31, 2021, 10:45:16 am »
If the config is OK, I can easily test the RF output from the Bridge. Some people have had damaged connectors too. I have repaired these for the cost of the part, and just ask for a donation to your local air ambulance.
Designer and maker of charge4.harkwood.co.uk, smart universal USB chargers designed for aviation.  USB power without the RF interference. Approved for EASA installs under CS-STAN too.

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #5 on: December 31, 2021, 04:23:19 pm »
hi Peter,

the MAC address is  B827EB94287B

does that help?

Its unlikely to be a fault with the aerial as i replaced it just before the flight on 22nd Dec however that doesn't exclude a fault with the Rosetta

i'm waiting for a weather window to get down to the plane to check the config

thxsa again

David


« Last Edit: December 31, 2021, 04:25:11 pm by crisisguy »

exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #6 on: January 01, 2022, 10:09:43 am »
Hi David,

...and a Happy New Year to you and all our followers,

N.B. Previous Post edited after my mate AlanG pointed out that default Hex ID’s all start with an ‘F’ (and I wasn’t drinking last night  :-[)

Thanks for the additional info. I have now rechecked the database for F4287B - which is the default Hex ID for that device and have found loads of PAW entries for your aircraft from 26 February 2021 up to and including your flight on 22 December, so that is definitely the reason you aren’t seeing anything on Vector from PAW from 406C84. This can be easily reset to the correct Hex ID in PAW/Configure (don’t forget to [Save] the changes).

Vector display is available for F4287B - but is only showing the results from 22 December as there is a time limit on the data held in Vector. The Vector display for 22 December looks very weak - especially if you are (as you say) using an external P3i antenna on the belly of your aircraft. The database itself shows reception on the 22nd out to 25Km, but most reports are at less than 10Km from the Ground Stations - which again doesn’t seem to reflect your external PAW antenna. This needs further investigation (but not today as I am being hauled off to visit the Grandkids).

I will get back to you.

Best Regards Meantime

Peter
« Last Edit: January 01, 2022, 12:16:26 pm by exfirepro »

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #7 on: January 09, 2022, 03:40:51 pm »
turned out i had the incorrect hex code in the configuration

seems to now pick up a PA reading on the vector diagram

exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #8 on: January 09, 2022, 10:56:14 pm »
Hi David,

Thanks for letting us know. I’m still a bit concerned about the relatively poor coverage reporting - you should be getting Ground Station PAW reports out to at least 20 - 30 Km with external antennas in an RV7. Where exactly underneath the aircraft are the antennas mounted and where is the PAW?

Best Regards

Peter

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #9 on: January 11, 2022, 01:55:10 pm »
hi Peter

Rosetta is mounted behind the dash and each Aerial is mounted by the pilot's feet, on the underside , the PA one on the right side and the other one on the left side

the ADSB antenna is about 300mm in front of the PA aerial

could it be to do with the ground plane? perhaps i did not do a thorough job of scraping off primer to get a good ground plane?


exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #10 on: January 11, 2022, 02:49:23 pm »
Hi David,

That’s possible, but it’s not necessarily the most likely cause. This kind of problem can be extremely difficult to diagnose remotely. Most problems with antennas turn out to be cable or connector faults. Were the cables commercially produced? If you were local, I’d put a meter on from the PAW end to check the combined cable and antenna for a good match (which if OK would move the emphasis of the investigation onto the PAW itself - though we don’t often see P3i transmit problems). First thing to check though, is that you have the correct antenna (the P3i is the longer one) connected to the correct SMA on your PilotAware. I have seen at least one case where the cables had got mixed up. PAW won’t perform well with it’s P3i Bridge connected to an ADSB antenna. If that is OK, do you have (or can you borrow) another coax to try, or can you try one of the PAW internal antennas on the P3i side?

Let me know how you get on.

Best Regards

Peter

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #11 on: January 14, 2022, 11:17:33 am »
hi Peter

Cables were purchased from yourself and i did triple check i had the correct connections to the rosetta

ill check again when next at the aircraft

i no longer have the internal aerials so that option is out


exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #12 on: January 15, 2022, 09:34:13 am »
Hi David,

Thanks for the additional info. That’s a fairly standard setup for an RV and pretty much rules out my two suggestions as likely reasons for the ‘weak’ PAW coverage report on Vector. For comparison take a look at the report for my aircraft 405A14 (a flexwing) - also using an external P3i antenna, mounted under the fibreglass pod with an aluminium foil ground plane on the inside of the pod. That’s the sort of report you should be getting.

I suggest you keep flying / checking and let us know whether the reports improve. If not we need to investigate further.

Best Regards
Peter

crisisguy

Re: Polar diagram shows no activity with PilotAware
« Reply #13 on: January 15, 2022, 09:49:32 am »
Thxs Peter

I am using 90 degree SMA adaptors to make the wire out easier to the aerial cables, any chance its these?

If not, next flight ill switch the outputs around to see if that makes a difference

exfirepro

Re: Polar diagram shows no activity with PilotAware
« Reply #14 on: January 15, 2022, 01:29:12 pm »
David,

Although any additional connector or adapter in a circuit technically introduces a slight loss, I’d be surprised if commercially produced 90 degree SMA adapters would make the kind of difference we are seeing - unless for some strange (unlikely) reason you have a dodgy adapter. You could try swapping the two of them over and see if that makes any difference.

The other thing you can do if you have one is check the cable from the PAW end* with a multi-meter (on one of the higher resistance settings). Putting the meter probes on the centre pin and the outer casing of the plug should show an open circuit (infinite resistance). If you get a low resistance reading, this indicates a short circuit somewhere along the line. First check for contamination (e.g. mud) between the radiating element of the antenna and its outer mount. If there is no contamination present, disconnect the coax cable from the antenna at the bayonet mount and repeat the check again. A very low resistance between the centre Pin and outer casing with both cable ends disconnected clearly indicates a fault in that cable. You can also check for continuity between the ends of the cable with the meter - centre pin to centre pin and outer casing to outer casing should in this case read low to zero resistance. A high resistance in this case indicates a break or bad connection.

* Only do this from the other end if you have disconnected the cable from the PAW as the meter injects a low voltage into the cable to carry out the test and this could damage the PAW.

Running the unit with no antenna (or a defective one) on the 869.5 MHz side is not recommended, but if you find that one cable is defective, you can run the PAW temporarily with the single ‘good’ cable on the 869.5 MHz (P3i) side to test your P3i output - you just won’t get any 1090 MHz reports.

Hope this helps.

Best Regards
Peter