Help please linking PAW to Funke TRT800H for ADS-B Out

[sdkellner]

Hi Peter

I had Mode C/S Beta + Filter (I have a Mode S transponder) with medium range.  The PA38 was close enough for me to identify it as Ravenair, and I know that they have at least Mode C; although it may have been tech/standby/off.  But I didn't see a single Mode C throughout my two hour flight on a glorious day with several other light aircraft visible to me, especially during my trip through the Hawarden overhead. 

I always click 'Save' to store the settings.

As for antenna position, I suspect my current location for the 1090 MHz antenna is less than ideal, but then again suitable places in an open cockpit gyro are hard to find!  It's located within the GRP nose cone just forward of the radio antenna.  I thought this would give me a good view forward, accepting the compromise of poor rearwards reception.   I may try shortening the antenna and locating it on top of my instrument binnacle just behind the perspex windshield.  The P3I antenna is again integral within the nose cone but directly behind the instrument panel, so again offering a reasonable view forward but obstructed rearwards.  There is no way I can install this antenna on top of the instrument binnacle; there is simply not enough room.  I would consider the tuned dipole (although it's been out of stock every time I've checked) but again I would be restricted for location; possibly on the forward section of the rotor mast, but I'm wary of anything this close to the prop being attached purely by sticky pad!  Cable ties required I think.

Playing back my ADS-B trace from Flight Radar 24 I can see that the points at which SD lost signal coincide with the ADS-B reception being lost; this strongly suggests to me that you are right about it being a power supply issue causing the PAW to either have a funny turn or reset rather than a wifi issue.  I use the GPS mouse on my instrument binnacle top and it usually sees at least 10 satellites.  I am running from ship's power via an Anker 12v cigarette socket dual USB adapter, although I also had the iPad connected to the second socket.  I might try running PAW from my Anker 20100 power bank next time.

I'm really pleased that ADS-B out seems to be working well, and now I need to work on bringing the rest of my PAW installation up to scratch.  It seems there's a bit of trial and error required to optimise the location within an individual aircraft; a great excuse for some tinkering on the many unflyable days we seem to be experiencing.

I'm blown away by what this little box is capable of; the PAW team has done an amazing job.  The sky would be a safer place if we all flew with PAW installed.

Best

Stuart

[Ian Melville]

Try running your PAW of a powerbank. After that I would disconnect your iPad, actually I would do this anyway. Though in an open and well cooled cockpit it won't be significant but Apple iDevices seem to only manage two of three things at once before they overheat on a hot day. Charging, screen on max brightness, and processing an intensive app like SkyDemon. Your iPad should have enough battery life for most flights and you can top it up from the powerbank between flights.

[exfirepro]

Stuart,

You are certainly working along the right lines. Your 1090MHz antenna should work OK inside the pod, but its always worth trying alternative locations, such as inside your windshield. As you know, you can cut the 1090MHz whip down, but don't go less than about 69mm as this might affect the alert triggers. Likewise, the P3i antenna will also work (at least forwards) from where you have it inside the pod, though this one is much more susceptible to screening as the power (and thus signal) levels it is working with are much lower. The best option for a P3i antenna (if achievable) is probably a PilotAware 1/4 wave monopole whip, mounted on the underside of the pod via an extension cable (unfortunately our 3m cables are currently out of stock) with a decent metal or metal tape ground plane on the inside. In tests in Keith's Sportcruiser, this sort of setup produced the most impressive results for PAW received signal distance.

OK on your power tests. The Anker USB adapter 'should' be able to power the PAW and charge your tablet, but if your tablet voltage is 'low' the high current required to charge it can still lead to RF interference, which usually disappears as the tablet approaches full charge. Another option to try if you suspect your PAW audio out is causing interference in your comms is a ground loop isolator, such as this...

https://www.amazon.co.uk/dp/B01LYYRT7M/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2LV7ZMZCH2EA&coliid=I3EYWWIE1Y1H4C

We have had good results with a couple of different versions.

Regards

Peter

[sdkellner]

Thank you Ian & Peter.

I am going to try running the PAW from my Anker 20100 power bank; if this improves matters I may go for the Charge 2.

I have ordered the ground loop isolator (thanks Peter); at £8 it's got to be worth a go.

I think I'll leave the 1090 MHz antenna where it is and explore options for the P3I as you describe and once stock becomes available.

I really appreciate all your help.

Stuart

[exfirepro]

You're welcome. That's how we all move forward.

Regards

Peter