FlightAware Discussions

Airspy R2 setup just changed

Morning all, something strange has happened to my set up over night. Nothing has changed settings wise and I have rebooted and checked all the internal connections and cant find anything wrong.

Lost a load of range and my signal level has shifted. Anyone see this before ? could it be weather related ?

System has been rock solid for the weeks…

Gain = 17
OPTIONS= -b -v -f 1 -x -e 10.7 -w 3 -t 120 -m 20

Please check if you have a similar issue i had recently.

https://discussions.flightaware.com/t/airspy-decoding-restarts-intermittenly/78012/14

Thanks, I have looked at all the connections and switched USB ports on the pi… The only connection I can’t get at easily is the one on the antenna itself. I still have the same problem. Bumping the gain to 21 doesn’t make any difference……

Yesterday there was torrential rain in the East of England with thunderstorms towards Leicester.
You could now have water in your co-ax, or less probably, a damaged AirSpy.
Are you using an LNA?

hmmm… that wouldn’t be good… its 10m up in the air :slight_smile: Guess I’m getting the ladders out at the weekend…

My set up is Pi 4 - Airspy - uptronics - long co-ax (10m) going outside to antenna. I triple wrapped the connection on the antenna with water proofing tape but I guess nothing is 100%.

You could try removing the Uptronics to see if the level drops by about 16dB.
If it does, that is good news because it will verify that the LNA is not damaged, however IIRC, the SAW filter is before the LNA so that could be damaged.

May be worth a look before climbing ladders.

Edit:
Be sure to switch off the Bias-T, if that is how your LNA is powered, you don’t want it shorted out by the antenna…

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I’ll have to look when I get home, remotely I can turn off bias T - then I basically see nothing. But that keeps the Uptronics in the loop but not powered…

Correct.  

Done everything inside the loft and can’t make any difference.

Do yo have a spare co-ax?

yes I do, the same as what I currently have installed. 7.5m not 10 but it’s the same. Going to swap it over at the weekend. I have pushed the gain to 21 tonight and its improved… I got it from the pi hut… Guessing its cheap… might look around see if I can get something better… Really don’t want to be going up the ladder more than once…

As the cable is after the output of the LNA, the loss is not so critical, however it always helps to not throw away signal, only to amplify again. LMR-400 or equivalent is a good cable.
Is the Uptronics LNA in a waterproof housing with N-Type connectors and a breather?

My LNA has been up in the air for a couple of years in an IP67 box and it is on my to-do list to lower it, check the gain, eliminate the 14 plus adaptors and re-test.
I will also compare the LMR loss against a spare.

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Hi, I have the Uptronics plugged directly into the airspy - then the long co-ax going to the antenna. All in the loft .
image

Sorry, I knew that from what you and I had previously posted, silly me.

Then, yes, the co-ax loss is important.

Just closing the loop. New co-ax installed and system is back to how it was. Would argue seams better but need to wait a few days. Paid the extra money for decent cable. Gain currently set to 16.