Number of Positions has decreased drastically

Over the past month, positions have dropped from about 600,000 to less than 300,000. Aircraft reported now under 2000, down from near 3000. Nothing has changed ref equipment. Using good/stick type antenna. Anyone have this occur? Fix?

I see that none of your nearby stations seem to be suffering similarly so it would appear to be something particular to your setup. I would start by looking for such things as damage to, or water getting into, your co-ax or possibly some new local interference.

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I will be start tracing the coax, so stay tuned. thanks

New local RF sources could also be interfering with your reception. Are there new cellular towers or anything like that nearby? Do you have a line filter installed?

No new towers. Live in rural area, so not too congested. No filter. Replaced coax and that helped maintain number of aircrafts, but postions are still way down. Not sure how much propogation effects, but it was a sudden drop-off.

how do you do that to check the cable?

check for water damage - visual. check continutiy- multi meter. check swr/ohm using meter. btw, so far cable looks good and I switched antennas to a colinier type - results so far are worse! the new one - [XR-172 ADS-B 1090 MHz 12DBi PCB Strip-Line 4 Half-Wave ]

Still no sucess with improving reception. Tried the following:

  • XR-172 ADS-B 1090 MHz 12DBi PCB Strip-Line 4 Half-Wave. Could never get better than 1:4 swr with 39ohms. reception actually reduced by half
  • homebrew spider antenna with 1:2 swr at 41ohms. still no better.
  • flightaware mag mount, no improvement
  • flightaware stick works the best, but still haven’t figured out why postions have decreased by half.
    With each antenna, using 50ohm coax, sma/n-type connector

Don’t use FA statistics, use something like graphs1090 to analyze reception.

still not too savvy with Pi programming. anything similar windows? thanks for the feedback. I will attempt to configure

There’s no programming involved. You simply copy and paste a command in the Pi’s terminal that then runs a script and installs graphs1090, then you can open it in a web browser on your PC: http://ip address of Pi/graphs1090.

It works with readsb too.

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