Sudden Loss of range

I did try -10. I will go back to that when I am done troubleshooting. It was -10 when I started. I am looking for other things (maybe hardware or physical problem in cabling/connector/filter) that could cause this sudden drop in range.

Thanks all for the help.

My Antenna is the 66cm one that flightaware sells on Amazon.

Nothing changed. It suspiciously looked like it happened at 00:00 UTC. I was away when it happened. There was no lightning only wind.

I think I might try upgrading the dongle. are these the two options – https://www.amazon.com/dp/B07J2RJQ9Z/ and https://www.amazon.com/dp/B0129EBDS2 that you are talking about? Is one better? If I am going to spend money to troubleshoot might as well get the higher performing one.

Thanks Wiedehopf for the insight and help

The rtl one is only better if you also get their LNA (New Product: RTL-SDR Blog 1090 MHz ADS-B LNA) which is extra money :frowning:

The blue dongle has an integrated LNA but the external one from rtl has better filtering and two stage amplification.
Also the external LNA you could install in a raintight enclosure close to the antenna.
But the more expensive combo should outperform even when you just install it indoors.
(And you of course hope it would being more expensive ;))

If you don’t want an external LNA the blue dongle is unbeatable. (you would probably still use the FA filter but you can try without and check which is better, will depend on the signals around you)

I got the blue one from FA that has preamp and filtering. It worked great for me. I kept poking around with different ones, but that was still the best.

Eventually I have bought a $99 one (AirSpy Mini) and that finally got better results, mainly because of the better DAC. But also required extra amplification (so more money).

Do I understand it correctly.? The RTL-sdr LNA requires power and it will get the power from their dongle?

So Here is my exact setup. I get an advantage from the filter. I assume it is because there are multiple high powered TV, radio, Cell all with in a mile from me. My setup is, Antenna, adapter, 10 ft cable, FA Filter, Orange FA dongle. The antenna is 5 ft off the peak of my roof. I have the tallest house around, so only some trees and the commercial antenna block me. Everything is mounted inside to the underside of my roof. Is it worth it to put the LNA outside when I only have a 10ft antenna extension cable?

Thanks everyone for the education. It was just plug and play and just worked before this.

Mike

No that’s likely not worth it :wink:
I’m using mine on the inside of the roof as well.

Yes the LNA needs some power and that is fed through the coax (you need to enable it in software, there is a guide how to do it (Getting the V3 Bias Tee to Activate on PiAware ADS-B Images))

Without power the LNA will block signals and you get literally no reception :slight_smile:

The blue stick already has an advantage over the orange stick regarding filtering: Like the orange stick the signal is amplified but then is filtered internally where the orange stick has no filter.

The filtering done by the rtl-sdr LNA is superior though and also the noise floor of the LNA is probably better. (very rough filtering comparison (Testing Signal Quality with Spectrum Analyzer? - #6 by wiedehopf))

Note that i’m not sure if i get the extra performance because of the filtering or the LNA is just better.
Maybe a combination of both. But i do notice fainter signals can be detected.

My maximum range fell off last March. I found it was caused by a kink in the feeding coax.

So the winner is jonhawkes2030 > Water was the issue. I had the connector on the Antenna protected and though water could not have gotten in there, well it did. It was a nice day for a walk on the roof and just checked, there was water and my signals bounced back. THank you Jon (and everyone else).

I have ordered the Blue Pro stick. I will compare it the Orange pro stick with external filter and post the results for anyone that is curious.

dump1090-localhost-aircraft_message_rate-24h dump1090-localhost-local_rate-24h dump1090-localhost-aircraft-24h

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The external filter might still be beneficial with the blue stick :slight_smile:

Would you mind posting your signal graph as well?
Or
http://pi/dump1090-fa/data/stats.json
:wink:

{
“latest”:{“start”:1541615794.3,“end”:1541615794.3,“local”:{“samples_processed”:0,“samples_dropped”:0,“modeac”:0,“modes”:0,“bad”:0,“unknown_icao”:0,“accepted”:[0,0],“strong_signals”:0},“remote”:{“modeac”:0,“modes”:0,“bad”:0,“unknown_icao”:0,“accepted”:[0,0]},“cpr”:{“surface”:0,“airborne”:0,“global_ok”:0,“global_bad”:0,“global_range”:0,“global_speed”:0,“global_skipped”:0,“local_ok”:0,“local_aircraft_relative”:0,“local_receiver_relative”:0,“local_skipped”:0,“local_range”:0,“local_speed”:0,“filtered”:0},“altitude_suppressed”:0,“cpu”:{“demod”:0,“reader”:0,“background”:0},“tracks”:{“all”:0,“single_message”:0},“messages”:0},
“last1min”:{“start”:1541615734.3,“end”:1541615794.3,“local”:{“samples_processed”:143917056,“samples_dropped”:0,“modeac”:0,“modes”:1427661,“bad”:910183,“unknown_icao”:504459,“accepted”:[11943,1076],“signal”:-7.4,“noise”:-21.2,“peak_signal”:-0.9,“strong_signals”:1312},“remote”:{“modeac”:0,“modes”:534,“bad”:0,“unknown_icao”:0,“accepted”:[534,0]},“cpr”:{“surface”:1,“airborne”:1368,“global_ok”:1305,“global_bad”:0,“global_range”:0,“global_speed”:0,“global_skipped”:1,“local_ok”:49,“local_aircraft_relative”:0,“local_receiver_relative”:0,“local_skipped”:15,“local_range”:0,“local_speed”:0,“filtered”:0},“altitude_suppressed”:0,“cpu”:{“demod”:14660,“reader”:5658,“background”:902},“tracks”:{“all”:9,“single_message”:3},“messages”:13553},
“last5min”:{“start”:1541615494.3,“end”:1541615794.3,“local”:{“samples_processed”:719978496,“samples_dropped”:0,“modeac”:0,“modes”:7109565,“bad”:4526857,“unknown_icao”:2509411,“accepted”:[67131,6166],“signal”:-7.2,“noise”:-20.9,“peak_signal”:-0.5,“strong_signals”:6863},“remote”:{“modeac”:0,“modes”:2889,“bad”:0,“unknown_icao”:0,“accepted”:[2889,0]},“cpr”:{“surface”:4,“airborne”:7933,“global_ok”:7597,“global_bad”:0,“global_range”:0,“global_speed”:0,“global_skipped”:9,“local_ok”:288,“local_aircraft_relative”:0,“local_receiver_relative”:0,“local_skipped”:52,“local_range”:0,“local_speed”:0,“filtered”:0},“altitude_suppressed”:0,“cpu”:{“demod”:73456,“reader”:28426,“background”:4623},“tracks”:{“all”:34,“single_message”:13},“messages”:76186},
“last15min”:{“start”:1541614894.3,“end”:1541615794.3,“local”:{“samples_processed”:2160066560,“samples_dropped”:0,“modeac”:0,“modes”:21238450,“bad”:13500948,“unknown_icao”:7488426,“accepted”:[228785,20291],“signal”:-6.6,“noise”:-20.3,“peak_signal”:-0.4,“strong_signals”:36727},“remote”:{“modeac”:0,“modes”:8091,“bad”:0,“unknown_icao”:0,“accepted”:[8091,0]},“cpr”:{“surface”:6,“airborne”:27545,“global_ok”:26549,“global_bad”:0,“global_range”:0,“global_speed”:0,“global_skipped”:20,“local_ok”:841,“local_aircraft_relative”:0,“local_receiver_relative”:0,“local_skipped”:161,“local_range”:0,“local_speed”:0,“filtered”:0},“altitude_suppressed”:0,“cpu”:{“demod”:221141,“reader”:86318,“background”:13760},“tracks”:{“all”:90,“single_message”:35},“messages”:257167},
“total”:{“start”:1541462434.2,“end”:1541615794.3,“local”:{“samples_processed”:366059061248,“samples_dropped”:0,“modeac”:0,“modes”:3763394551,“bad”:2409141367,“unknown_icao”:1340093381,“accepted”:[12982191,1177612],“signal”:-7.6,“noise”:-23.3,“peak_signal”:-0.4,“strong_signals”:1174745},“remote”:{“modeac”:0,“modes”:414633,“bad”:0,“unknown_icao”:0,“accepted”:[414633,0]},“cpr”:{“surface”:655,“airborne”:1649676,“global_ok”:1592016,“global_bad”:11,“global_range”:6,“global_speed”:2,“global_skipped”:1111,“local_ok”:43586,“local_aircraft_relative”:0,“local_receiver_relative”:0,“local_skipped”:14718,“local_range”:1,“local_speed”:24,“filtered”:0},“altitude_suppressed”:0,“cpu”:{“demod”:37537121,“reader”:13894732,“background”:1744114},“tracks”:{“all”:10903,“single_message”:6692},“messages”:14574436}
}

dump1090-localhost-signal-24h

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For the last 15 minutes that is 36727/(228785+20291) = 14.7 % of strong messages. (>-3dB, nearly too strong to be received hinting that you didn’t receive some stronger messages because the signal was too strong)

You should probably try 49.6 instead of -10 now for the gain :wink:
Probably higher message rate but not sure if it would cut range, probably not much if at all but hard to say without testing.

Oh and the red area in the Message Rate graph is kinda bogus, it represent the derivative of the messages > -3dB which is not that useful.
I’ve written a fix you can read about and download if you want:
(Optimize Gain - which would you chose - #174 by wiedehopf)

I was coming here to start thread on loss of range. I went from an average track of about 180 nm to just about 55 nm.

I read a comment about water and another gentleman who said his range was indeed affected by water intrusion at the antenna. I pulled my antenna apart and sure as crap water in the connection.

I used a few q-tips some rubbing alcohol and compressed air to clean them out and the range went back to normal.

Thanks for the postings.
Tim

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Thanks for checking the forum before you posted, not everybody does that…:+1:

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Put some silicon grease inside any outside connectors. It won’t affect the connection, but it will keep water out and inhibit corrosion.

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Thanks!

I went back up and added some dielectic grease.

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I wonder: will WD-40 do too? For example at the coax connector of the FA antenna.

Update: possibly not: eHam.net (bottom comment).

I wouldn’t use mineral oil based products or greases.

The big plus of silicon oil / grease is that it won’t degrade plastics.

Possibly the most misused substance on the planet. WD-40 is a water dispersant and cleaning solvent, but it’s not persistent enough to provide long term protection. It can be used to get rid of water that already there, but as wiedehopf says mineral oils often attack plastics. With coax it could wick up inside and damage the dielectric foam or core.

Silicone or dielectric grease won’t cause damage to plastics, and it won’t affect the impedance of the connection.

You could do it the fisherman’s way and wrap everything in denso tape, but I wouldn’t recommend it. It would be waterproof but cleaning it of again isn’t much fun.

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Try the following:

“Wrap once with self amalgamating tape (Scotch 2242 or 3M 2155 Temflex, available at home stores) and follow this with a layer of Scotch 33+. The 33+ is required to achieve UV resistance. This combination cuts apart cleanly if needed for maintenance.”

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I use
" Proxicast Pro-Grade Extra Strong 30mil Weatherproof Self-Fusing Silicone Sealing Tape For Coax"

You can read about it here, and get it on Amazon as well:
http://shop.proxicast.com/shopping/proxicast-pro-grade-extra-strong-weatherproof-self-bonding-non-adhesive-30mil-silicone-sealing-tape-1.5-x-15-roll-black.html

Has held up well for years, easy to cut off and re-apply when re-doing cabling, antennas, etc.