Hi all,
I got my first Pi and dongle just over a month ago. Thanks to wise words from this forum and others - and some experimenting - I think I've got it working as well as I can expect.
I've got a few things in my local environment that I think are limiting what I can expect. I've got some ideas about next steps and I'd like to know what people think.
Local issues:
- Large building, a shopping centre (mall) within 75m
- Mobile phone mast within 50m
- Several airways nearby, and I'm midway between Heathrow and Luton so lots of aircraft at all heights.
I'm running with the dongle and antenna shown on the build your own page (jet vision dongle and small antenna). I've got a SAW filter fitted. (I bought a flightaware filter first then realised the passband was too wide for the UK.) Even with the filter quite a bit of signal is present at 960 MHz, note it's a unenclosed PCB. I've managed to set the gain to give noise around -40 and peak signal around -3. I suspect it's being limited by both the phone signal and by high levels from aircraft overhead. Perhaps the bit depth is a factor too, but I plan to start another thread for that discussion.
So, my thoughts. Do I:
- Get a separate LNA (allow the dongle to run at lower gain)
- Ditch the dongle and get a FlightAware Pro Stick Plus (as above, but neater and fewer connections)
- Build Co-ax colinear antenna (lower gain overhead the site)
I'm leaning towards that latter because it's more fun, but I suspect the new dongle would give the best improvement.
All thoughts welcome. Wow, that's a long post (sorry).
Freddie
I got my first Pi and dongle just over a month ago. Thanks to wise words from this forum and others - and some experimenting - I think I've got it working as well as I can expect.
I've got a few things in my local environment that I think are limiting what I can expect. I've got some ideas about next steps and I'd like to know what people think.
Local issues:
- Large building, a shopping centre (mall) within 75m
- Mobile phone mast within 50m
- Several airways nearby, and I'm midway between Heathrow and Luton so lots of aircraft at all heights.
I'm running with the dongle and antenna shown on the build your own page (jet vision dongle and small antenna). I've got a SAW filter fitted. (I bought a flightaware filter first then realised the passband was too wide for the UK.) Even with the filter quite a bit of signal is present at 960 MHz, note it's a unenclosed PCB. I've managed to set the gain to give noise around -40 and peak signal around -3. I suspect it's being limited by both the phone signal and by high levels from aircraft overhead. Perhaps the bit depth is a factor too, but I plan to start another thread for that discussion.
So, my thoughts. Do I:
- Get a separate LNA (allow the dongle to run at lower gain)
- Ditch the dongle and get a FlightAware Pro Stick Plus (as above, but neater and fewer connections)
- Build Co-ax colinear antenna (lower gain overhead the site)
I'm leaning towards that latter because it's more fun, but I suspect the new dongle would give the best improvement.
All thoughts welcome. Wow, that's a long post (sorry).
Freddie
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