ADSB receiver back online

Finally got my spare parts for the Raspberry Pi PoE hat and put the ADSB receiver back online. It took DHL Express almost 6 days for the customs clearance, was the last time I used this carrier. UPS is way more efficient on that.

I used the outage for an upgrade to the Mode-S Beast receiver. The performance of the neat little thing is astonishing! Compared to RTL-SDR dongle the ADSB message rate is 3 times higher, I see 40-50 more aircrafts, tracks per hour increased by 300-400, range increased by around 70km and CPU usage is down to 2-3%. That’s with the G7RQG antenna, connected by a short coax cable (<1m).

My dump1090-fa fork now supports the Mode-S Beast directly via USB. See Github for details.


ADSB receiver (gr || k)illed

Today, a thunderstorm passing overhead just killed, or better grilled, my ADSB receiver. There was no direct lightning strike but for some reason the DC-DC converter on the PoE hat stopped working and shows a short on the 48V input. The Raspberry Pi and everything else on the 5V side is working just fine. The PoE hat is powered by a 48V switching supply off the 220V mains. That is also still working fine, probably because of its output short circuit protection.

On the PoE hat the DC-DC converter is a Silvertel AG9805-M, ordered some new from http://www.semiconductorstore.com. $8/piece is a good deal compared to the price for the PoE hat or replacement converters supplied by other manufacturers.

I will stock some spares just in case that happens again. But then I need to investigate why that thing breaks.


NESDR Smart performance

Today I tried my G7RGQ antenna together with a NooElec NESDR Smart stick connected to the ADSB Raspberry Pi. I put the antenna and the stick on the roof and had it running for a while. To my surprise the performance was not as expected. I needed the same a gain setting to archive results comparable to my QFH antenna with 6m coax to the receiver. Again, I removed 6m of coax, around 6dB attenuation, but results were ain’t better. Took everything down again and disassembled the setup for testing.

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dump1090 – Gain vs. Performance

I took the opportunity for some experiments with gain settings in dump1090-fa while testing a new built antenna for the ADSB receiver. I compared my previously built QFH antenna to a G7RGQ omni directional antenna that I built last week. Second object of test was a 10m active USB cable (from Amazon).

1090MHz QFH on the left. G7RGQ omni on the right.

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