FlightAware Discussions

Anyone tried the Uputonics ADS-B LNA with a pro stick Plus

Hi New member (well been doing this for a good few weeks now )
my problem is reception I have the airnav ADS_B antenna on the top of my roof as thats the highest point I can use
it feeds into my Prostick plus that runs on a Pi 3 with flight aware installed and networked for MLAT
I struggle to get message rates of on average for more than about Messages: 178/sec
this is most likely as east and west I can get up to 200 miles but north & south is an issue
to the south I have about 10 deg of horizon loss due to hills & tree’s north is only a little better as I stay in one of the lowest places around me

I use an Uputonics 137.5 LNA which I added to my weather tracking setup last week with very good results and increased distance by a good margin
I know they have a 1090 model as well but not sure if the gain would be overkill and could swamp the pro stick and make the situation worse

I’ve tried playing with the gain settings in the /etc/default/dump1090-fa but when I change the settings and restart dump it reverts back to its default -10 (the file does say its overwritten on restart)

my best days are up to 30 aircraft at any one time but norm is more like 15 on average would just like a bit more range if thats possible

any advice of anyone used the Uputronics LNA I’d love to hear your experience

thanks John

The piaware sd-card image requires a different method to change the gain:
For Beginners - How to Set / Change Gain

Looking at your pie graph for range in different directions, it looks like you might just be limited by range in a few directions.
What is the Maximum Range I can Get?

You really can’t improve that with an LNA. You need more or less direct line of sight for ADS-B.

The uputronics LNA can work fine with the ProStick Plus.

If you have a long antenna cable run, it’s optimal to install the LNA near the antenna.
What antenna/cable are you using anyway?

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Airnav ADS_B antenna with a 10m feed of RG58 that seems to connect direct to the antenna ( I could cut & patch it)
I have a 15m feed of RG58 running from my Log periodic back to the Uputronic’s 137.5 and it seems to work good if not optimal
yes north and south of me are high ground so not helping my situation

I followed the “how to” but seems I took the wrong option
will play with it and see if my results improve THX

bugger it ordered one to see what it can do
playing with my weather one I find the gain a little high so I back it off in the software AGC settings but it does have a vast improvement in my coverage in all directions when you find the sweet spot

pi@piaware:~ pi@piaware:~ awk “$(cat /run/dump1090*/stats.json| grep total | sed ‘s/.accepted":[([0-9]).strong_signals":([0-9]).*/BEGIN {printf “\nPercentage of strong messages: %.3f \n” , \2 * 100 / \1}/’)”

pi@piaware:~ $ Percentage of strong messages: 5.048

seems like I’m getting there

Ok its arrived and working very well
without tweaking anything I’ve gone from average 15 - 20 planes on average to over 40 with a decent increase in range in all directions
once I see how it settles I’ll then look at tuning the Db settings

happy chappy

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set the Db level at 22 and getting a constant low 5% and much improved data
will need to see in a few days the actual improvement but my message count is well up on the last week as is my tracks and distance

so far pleased with the Uputronics box and no drama’s setting it up or tuning it in

Percentage of strong messages: 5.055

RG58 is one of the worst cables for these high frequencies, because you lose a lot of signal due to the attennuation at 1090MHz.
It is best practice to place the LNA as close to the antenna as possible (within 1m)

If this is not possible, then replace the cable between antenna and LNA with a good quality low loss cable i.e. Messi & Paoloni Hyperflex 10 or LMR400. Keep it as short as possible. After the LNA cable attenuation has less impact, so you could use a cheaper cable (i.e. RG6 is cheap, has good specs, despite the impedance mismatch this performs better than RG56).

At 1090MHz:
10m RG58 has an attenuation (=loss) of 6 dB (!)
10m LMR400 has an attenuation of 1.7 dB
10m Hyperflex 10 has an attenuation of 1.4 dB

Each 3dB means half of the original signal is lost, so with 10m RG58 only 25% of the original signal will be left, which translates to less range.

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I have four or five.
I use them for 978Mhz(UAT), 1090Mhz(ADS-B), APRS (144.390Mhz) and 156Mhz (GMDSS).
They work well.
I did need a cavity filter for UAT and ADS-B as I have a lot of noise in my location (A dozen cell towers within a few blocks).

How well do they work on 137.5Mhz? I wanted to play with Satellite weather images but the antennas are a little expensive(I have no interest in building one).

I ran a SatNOGS station for about a month. My main interest were the NOAA satellites. I used a RadioShack discone antenna, and it worked OK. The limiting factor was having it at 6 feet above ground level, only about half of each pass was visible to the antenna due to obstacles.

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