TEST 1: "Blue" DVBT dongle vs Blue dongle+OGN-01-VLNA vs FlightAware dongle with SAW
Test conditions:
- Test site with strong GSM/LTE signals
- Distance to the two nearest BTS stations: 280m and 150m
- Antenna: 5dBi Kathrein K7515641
- Spectrograms generated by RPI based OGN test receiver
- Dongle gain: +48dB
- Three configurations tested:
- Standard, "Blue" (RT820T2) DVBT dongle without external LNA
- Blue dongle with OGN-01-VLNA connected
- Modified FlightAware (orange) DVBT dongle with SAW filter placed between internal LNA and RT820T2
- FlightAware (orange) dongle without SAW filter *NOT* tested (Rf.Input.Noise reported > 35dB, dongle completely overloaded)
GSM/LTE interference visible for blue dongle configuration.
Very good ISM sensitivity and resistance to the strong GSM/LTE signals for Blue dongle + OGN-01-VLNA setup.
Very strong GSM/LTE interference for modified FlightAware dongle.
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TEST 2: ISM band receiving quality, ISM vs GSM/LTE signal strength levels and OGN-01-VLNA vs FlightAware dongle comparison
Test conditions:
- Distance to the two nearest BTS stations: 920m and 1150m
- Test site around 2 km from the Piotrkow (Poland) city
- Trees around test site (additional attenuation for ISM/GSM/LTE signals)
- Antenna: 8dBi Kathrein K736350, 2 meters above ground level
- Gqrx software used as a spectrum analyzer
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Reference setup. DVBT "Blue" dongle (RT820T2). +49.6dB dongle gain. No external LNA connected.
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OGN-01-VLNA connected. Total system gain around +77..78dB. Overall receiver noise figure around 0.4...0.5dB
Best SNR and receiving performance from all four setups. Clean spectrum, very high GSM/LTE attenuation.
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