How to sqeeze everything out of my receiver


#1

Hi, I’m relatively new into ADS-B and feeding my datastreams for about a month. Since that time I made a lot of improvements to my setup.

I’m happy with my current setup, but I was wondering if there are some “hacks” to sqeeze even more out of my receiver.

Current setup is as followed:

  • RPi 3 with aan official 2,5A power supply, running the standard Piaware software
  • Flightaware Pro Stick dongle
  • Flightaware ADS-B filter
  • short length (2 meters) of Aircell 7 Coax with Aircell 7 N-connector and Aircell 7 SMA connector (no adapters, pigtails etc.)
  • Flightaware antenna, placed at the highest point on top of the roof, outside (approx. 10m AGL)

I tried with and without filter. The results remains the same. Placing the antenne on a higher position is no option.

So, Acccording to my little knowledge about ADS-B, I’m out of options to get even better results. Perhaps you experts have some ideas? Can I tweak some settings on the soft side of my setup?


#2

Optimising the gain adjustment made the most difference
look at ads-b-flight-tracking-f21/gain-adjustment-t37172.html

I had to reduce my gain to 38db for the best results, however, each setup is unique.

If you have the STD image you may need to do it manually.
flightaware.com/adsb/prostick/setup/

There is also a new image due out shortly. It should have a number of performance improvements.


#3

removed


#4

True I took my laptop running dump1090 with FA Pro stick to a high spot so that I could pick up a couple of Spitfires that were performing at a local event. Although they were visible there was no sign of them in my VRS aircraft list but I was receiving aircraft from long distance as I guess the data was being swamped.

Sent from my GT-I9100 using Tapatalk


#5

Get yourself decent coax cable like ECOflex-15, Aircom + or Ultraflex 13, because Aircell 7 is crappy cable for 1090 MHz (loss @ 1 GHz/100m 21,52 dB)
And take a look at Dump1090 mutability


#6

Thanks for the tip. Do you think that will that give any measurable effect if the coax cable is only 2 meters long? If so, it’s worth to give it a try. If it’s only in theory, I would rather stay inside than climb on the roof again to replace the cable. 8)

I thought the Aircell 7 was a good option for this, as it is suitable for frequencies up to 6GHz.

Dump1090 Mutability is one of my next steps to do. Although… rumors about a new, improved, Piaware version made me wait for a while.

Thanks! I have tried different gain settings manually, but it’s hard to see any differences. Standard setting was -10 (auto gain control???). But I keep trying.


#7

torroid chokes on the USB pigtails(if used) and power cables. May reduce noise.
A metal case for the FA Dongle and the RPI itself may also reduce noise.
Keep the RPI CPU cool. Mine drops MLAT when it gets too hot. A case with a fan fixed the issue.


#8

Thanks! Cooling issues already have my attention. I ordered a metal case with fan for my Pi and I already have placed heatsinks. A metal case for the FA pro stick is a good one, and Chokes for the powercables too.


#9

The FA Prostick will get very hot also. Even more so than the RPi 3.

Once you’ve enclosed your Prostick in an aluminum case, consider adding some heat sinks to the exterior of both sides of the case.

BTW, I also removed the LED of the Prostick before enclosing it in the new case.


#10

Aircell 7 appears to have roughly the same spec as any typical plenum rated RG6, commonly used by ADS-B’ers. Two meters of this cable probably gives less than .5 dB of loss at 1090. Inconsequential. The extra losses incurred by the changeover is not much either.

Sure, ideally, one should use 50 ohm high quality cable between the 50 ohm antenna and the 50 ohm-ish SMA port on the dongle. But, two meters of RG6 and two impedance changeovers isn’t going to be much different than two meters of LMR600 and a N to SMA changeover.

Height, a higher gain antenna, or maybe even try using a directional antenna pointed towards the ‘hottest’ region.

My present ADS-B collector is running with a 820T2 dongle, a 15 dB LNA (not a satellite inline amplifier), 15’ of LMR400, and a 5 dB antenna at about 50’ HAAT, no gain argument and no agc argument.


#11

Aircell 7 gives a loss of 0,4 db whit 2 meter of it.
if you use a diferent cable you dont see de difrence.
the flightaware filter gives much more loss.
if you want more range the only thing you can do is the height of the antenne.
And find the correct settings whit the gain setting.
i always use planeplotter and look at the message rate and then play whit the gain settings when the gain is to hard the message rate drops .