Maximum message count rate?


Looking back over past discussions there was talk of a theoretical maximum message count … I get the distinct impression I’ve hit that limit of around 1500 msgs per second - if indeed it does exist. However the earlier discussion lost me when they began to talk of targeted sectors and directional antenna …

I have a shiny new (DPD) antenna; more aircraft yet the same message count … early days but …

Any thoughts?

Kind Regards



I’m sure there are others that will do better than myself, but i was at about 1750 m/s with 307 aircraft tracking when I looked this morning…

Thats with a FA Antenna, 6m Ecoflex Coax, Uputronics Amp and RTLSDRv3 stick onto a cabled RPi (no wifi).
Hoping to move the amp up onto the mast this weekend!



Thank you for that reassurance - I have an SDR stick & preamp to try out. There is a station close to me that receives >1,800,000 msgs a day!

Kind Regards



I was getting 1700 m/s and 240 plane count this morning.

I’ve never seen my messages/sec much above 1700.

FA antenna, 5m unknown coax, FA Prostick (Yellow), Pi 2 Model B v1.1, PiAware image, Dump1090 running at about 35% CPU.


Hi triggers!

  1. I remember you have been using a 12 element CoCo for a long time. When you switched from CoCo to FA antenna, how much was improvement?
  2. Have you tried a Filter?
  3. What happened to your directional Yagi / Sector antenna project, aimed at planes landing / on ground, at nearby airport?


Hi ab cd,
I haven’t spent any time with ADS-B for a couple of months but I do try to read the forum at least once a week. Here are your answers:

  1. 12 element CoCo has been parked in the shed after mounting the FA one. Not much improvement was noted but the FA antenna is much shorter than the CoCo so much easied to mount :slight_smile:

  2. Tried the FA filter and a SAW filter I built myself but found fewer planes and less distance. I am in the countryside so no phone masts in the area.

  1. I built a Yagi which gave good response to the East where Heathrow is, but I have the Chiltern hills in the way. I don’t think I’ll ever pick up planes on the ground. I’ve been messing about with building several directional antennas but nothing to report - yet!


Did you try WiFi Wave Guide Type Cantenna?


At the extreme distances, the angle that you “see” the plane above horizon is very small. Objects in the path, even if smaller than your antenna height, will block that direct line of sight (or at least partially, some diffraction might pass around).

I’m in the same situation - I can “see” planes past Washington Dulles airport (less than 150 miles), if they are at 28-40,000 ft. I see nothing of the actual IAD traffic, it’s too low.