Testing PilotAware setup in plane

[Deker]

You can phase two antennas by feeding each antenna to a tee with 75ohm coax (multiple of odd 1/4 wavelength lengths of coax).
From the tee, use 50 ohm coax to the transmitter or RX.

But the question is, with PAW do you need to?
I was getting Pi3 traffic reports at 30KM+ with the standard antenna sat on the dash.

ATB
Deker

[Ian Melville]

I think the idea is that by using two antenna, they can be placed to cover blind spots due to engine and the bag of water.

Never tried what you suggest, but am very weary of faffing around with stuff that transmits. Get it wrong and pop goes your bridge unit.

[exfirepro]

Hi Guys,

Deker is correct in his advice. I did quite a bit of 'fiddling' with multiple stacked 'yagi' antennas in my Ham Radio competition days. In those days I was regularly playing with 400Watts of RF at HF, VHF and UHF. I still have some of the hi-tech matching units in the shed that we built to combine the antennas. Unfortunately, the maths to build them properly is fairly complex and you need to get it just right to ensure a correct impedance match to the output stage of the transmitter or all is for naught!

As you say Deker, with P3i reception from up to 30k out with a simple antenna fit, you would need to be very unlucky for a rogue aircraft to approach all the way in with your engine(s) / body(ies) between your respective antennas.

Regards

Peter

[Chris Parsons]

Having had my PAW for a while I thought it was time I got it fitted and took it airborne?

Looks like the link to the antenna placement guidance is broken, but from a quick look/read
around it seems a simple test would be to use a portable battery pack with it all sat on the top of
the coaming (top of instrument panel?) with the small aerial stuck down (with a velcro pad)
in the middle of the top of the panel and with both aerials vertical? Hopefully this won't be in the
way too much!

I have a fixed wing microlight (EuroFOX) so have limited space and want to find a home for it
where it doesn't get booted everytime I climb in and out!

On a different note, I have noticed when ground testing that the ADS-B 'counter' shown on the web
interface sometimes freezes - when I unscrew the aerial a bit and retighten it, it starts counting again,
is my aerial stuffed?? I like the idea of shortening the cable and the aerial but don't want to start cutting
anything until I have seen it all working - I was hoping that I could have a look at my recorded track on
FlightRadar24 or have I missed the point somewhere? Is this only possible when you are hooked up to
the transponder and transmitting your position? (which might be another issue as I have a Funke TRT800
and I am not sure if this will work with the PAW?)

Regards

Chris Parsons

[exfirepro]

Having had my PAW for a while I thought it was time I got it fitted and took it airborne?

Looks like the link to the antenna placement guidance is broken, but from a quick look/read
around it seems a simple test would be to use a portable battery pack with it all sat on the top of
the coaming (top of instrument panel?) with the small aerial stuck down (with a velcro pad)
in the middle of the top of the panel and with both aerials vertical? Hopefully this won't be in the
way too much!

I have a fixed wing microlight (EuroFOX) so have limited space and want to find a home for it
where it doesn't get booted everytime I climb in and out!

Hi Chris,

Pretty much all correct. Remember the aerials need to be vertical, but can be hung from the roof, or in the Eurofox will probably work fine fitted in the cockpit behind you. In fact with a front mounted engine, higher up and further back is usually better.

On a different note, I have noticed when ground testing that the ADS-B 'counter' shown on the web
interface sometimes freezes - when I unscrew the aerial a bit and retighten it, it starts counting again,
is my aerial stuffed??

The ADSB counter will stop if you are not receiving any aircraft transmissions. This can be for many reasons e.g. there just aren't any ADSB aircraft within reception range and does not necessarily mean there is any problem with your system.

I like the idea of shortening the cable and the aerial but don't want to start cutting
anything until I have seen it all working

Good call - no problem in trimming the 1090MHz antenna and cable but make sure everything is working well first

- I was hoping that I could have a look at my recorded track on
FlightRadar24 or have I missed the point somewhere? Is this only possible when you are hooked up to
the transponder and transmitting your position? (which might be another issue as I have a Funke TRT800
and I am not sure if this will work with the PAW?)
Regards

Chris Parsons

Correct - you will only appear on FR24 if you are transmitting Mode 'S' from a transponder - and then only if you are in an area where FR24 has effective 'multilateration' known as MLAT, which means multiple receiving stations so they can triangulate your estimated position from your Mode 'S' signal - or if you are TRANSMITTING ADSB - which PilotAware does NOT do directly, though it can be used to supply a GPS signal to your Mode 'S' transponder to make this ADSB out. Pretty sure you will be OK - try doing a search on 'TRT800' from the forum Home Page - lots there to read.

Regards

Peter