PilotAware

British Forum => Technical Support => Topic started by: stillstanding on April 23, 2018, 08:59:00 pm

Title: Transponder signals received intermittently
Post by: stillstanding on April 23, 2018, 08:59:00 pm: I've been using my PilotAware for over a year without problems. However during the last few flights the reception of ADSB and transponders appears lacking, but PAW signals are OK. (I know this thanks to a local ground station).

On Saturday I checked the web browser screen and all the status tags were green. However during the flight the connection to my iPad failed a couple of times too. Prior to this I removed and refitted all bits, checked the transponder reciever aerial for continuity, checked bridge card fitted ok etc.

I had originally thought the receiver dongle might be failing. If this is the case could it be intermittent and could it cause the Raspberry Pi to restart?

Thanks,

Mike
Title: Re: Transponder signals received intermittently
Post by: Ian Melville on April 23, 2018, 09:21:06 pm: If it is rebooting, can you state your power supply kit?

ADSB Dongles can go down, they do run hot, and I am sure that shortens there life.

Regarding connection issues, we are working on that.
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 23, 2018, 10:27:00 pm: Thanks Ian. Power supply is the recommended Anker PowerCore 20100 with the supplied JuiceBits cable. Its been fine for the past 15 months.

I'll see if I can run it for a couple of hours tomorrow on the ground.
Title: Re: Transponder signals received intermittently
Post by: Ian Melville on April 24, 2018, 05:57:19 am: Same power as I use without any issues. You can tell if the PAW has rebooted, by the time shown on the home page, for the time it has been running. I.e. It is shorter than you expect.
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 24, 2018, 12:02:10 pm: I've had the PAW under test this morning. Due to rain I wasn't able to site it outside and by the window it has hardly picked up any ADS-B traffic. There were times when it did detect traffic, but I didn't manage a screen grab in time.

Over an hour it hasn't done a reset either. The logging shows lots of errors, do these indicate anything?
Title: Re: Transponder signals received intermittently
Post by: Admin on April 24, 2018, 12:24:50 pm: Hi Mike,

I would first suspect either the connector on the SDR dongle, or the antenna itself.
Can you double check these ?

Thx
Lee
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 24, 2018, 05:18:03 pm: Thanks Lee.

I've just dissected it and it looks OK to me. I'll increase the earth braid before reassembly.

Forgot to mention earlier, after I did the log screen shots I shut the PAW down and the dongle was cool. Others say it runs very hot. Could this indicate it has failed?
Title: Re: Transponder signals received intermittently
Post by: Admin on April 24, 2018, 05:24:50 pm: Hi Mike,

It is still listed in the table of USB devices as can be seen from the listing on the home page, so appears to be still functional

I am still suspecting the antenna in some way, but without access to a spare antenna/dongle, its difficult to perform a swap and test

Thx
Lee
Title: Re: Transponder signals received intermittently
Post by: exfirepro on April 24, 2018, 05:33:10 pm: Mike,

If you have a multimeter, try a continuity test from the centre wire at the antenna base to the centre pin of the MCX plug. Also worth trying a short length of thin wire - bare or insulated - inserted carefully into the centre contact only of the SDR antenna connection as a temporary antenna. If the SDR is OK that should be enough to let you ‘see’ commercial ADSB or Mode S on your PAW Traffic Screen.

Regards

Peter
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 24, 2018, 09:52:58 pm: Hi Peter,

There seems to be continuity between the centre pin of the antenna plug and the centre wire of the antenna base. However there is an open circuit between the outer of the plug and the cable screening in the antenna base. Is that correct?

I'll try a makeshift antenna tomorrow, that sounds a good idea.
Title: Re: Transponder signals received intermittently
Post by: exfirepro on April 24, 2018, 10:15:57 pm: Mike,

Yes, there ‘should’ be continuity between the braid at the antenna base and the outer at the plug and of course no direct connection between the inner and outer of the cable. Worth trying a bit of wire instead to see what happens - length isn’t critical at this stage.

Regards

Peter
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 25, 2018, 12:14:00 pm: Well, the thin bit of wire stuck in the dongle has solved the problem, full system working for 90 mins now. So it looks like discontinuity in the antenna ground.

Being tight fisted I've cut the antenna cable down to 100 mm of the plug to see if I could just repair it, but it must be broken at the plug. So there goes another £2.28 on Ebay. This flying business is all spend!

Thank you everyone for you help in this, very grateful!
Title: Re: Transponder signals received intermittently
Post by: Admin on April 25, 2018, 01:50:53 pm: Good catch Mike !
Title: Re: Transponder signals received intermittently
Post by: exfirepro on April 25, 2018, 01:53:33 pm: Hi Mike,

Glad you’ve got to the bottom of it. Not so easy to sort out a broken connection at the plug end and it will cost you more than £2.28 unless you already have the bits (and a crimp tool).

Regards

Peter
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 25, 2018, 04:51:17 pm: Well, I forgot I left the PAW in the garden, went out just now and its got wet from the rain!!! Here's hoping no damage done. >:(
Title: Re: Transponder signals received intermittently
Post by: exfirepro on April 25, 2018, 05:12:36 pm: Oh No!!!!! :(

I have also done that before with no disastrous effects. From my own experience the case is fairly good at shedding moisture. You will already have pulled the power so dry it out carefully (mild heat is OK) before powering it up again - and keep your fingers crossed.

Let us know how you get on.

Regards

Peter
Title: Re: Transponder signals received intermittently
Post by: stillstanding on April 26, 2018, 08:03:46 am: All working just fine. I thought the sticker was definitely ruined as it was transparent, but even that looks OK.

Phew, thanks all,

Mike
Title: Re: Transponder signals received intermittently
Post by: Paul_Sengupta on April 30, 2018, 10:52:55 pm: Antennas available for 99p here.

https://www.ebay.co.uk/itm/High-Gain-Signal-5dBi-Antenna-Aerial-Digital-Freeview-For-DVB-T-TV-HDTV-Black/112435558439 (https://www.ebay.co.uk/itm/High-Gain-Signal-5dBi-Antenna-Aerial-Digital-Freeview-For-DVB-T-TV-HDTV-Black/112435558439)