SDR
Revision as of 22:01, 3 June 2015 by <bdi>PhilippeTeuwen</bdi> (talk | contribs) (→524 to 542 MHz wireless microphones)
Hardware
HackRF
- 1MHz - 6GHz, RX/TX half-duplex, BW 20MHz, ADC/DAC 8bit
- https://github.com/mossmann/hackrf/wiki
- Bias-T supply can deliver 3.3V 50mA
- BW & filtering: https://github.com/mossmann/hackrf/wiki/Tips-and-Tricks
- FW flashing
Airspy
- 24MHz - 1.750GHz, RX, BW 10MHz (9MHz alias free), ADC 12bit (10.4 ENOB)
- Bias-T supply can deliver 4.5V
- FW flashing
RTL-SDR
- ~25MHz - 2GHz, RX, BW 2.4-2.8MHz, ADC 8bit
- Mine: 52-2212 MHz with gap @ 1107-1241 MHz
LNA: Low Noise Amplifiers
- LNA4ALL
- 28-2500MHz, gain about 22dB from 28MHz to 600MHz then gain drops to ~16dB @ 1400MHz and ~11dB @ 2500MHz, 0.75dB NF @ 1 GHz and 0.98dB NF @ 2 GHz
- 6-9 V, 55-65 mA (5V if regulator bridged)
- can be powered by HackRF or Airspy if modified, 10uH SMD on OUT and regulator bridged (because we deliver <5V) or bridged by 100mA fuse, just in case.
- LNA4HF
- 150kHz - 30MHz, gain 18-20 dB, NF 1-2 dB
- 6-9 V, 18 mA (5V if regulator bridged)
- up to 2GHz if low-pass filter removed
- Better to position LNA near antenna than near receiver, more useful info here
Antennas
ANT500
- 50 ohms, 75 MHz - 1 GHz, 20cm - 88cm
Software
- https://github.com/mossmann/hackrf/wiki/Operating-System-Tips -> PyBOMBS
- HackRF specific: https://github.com/mossmann/hackrf/wiki/Software-with-HackRF-Support
Reverse engineering
FCC
Generic
- GQRX
- hackrf_transfer + baudline
27MHz RC
87MHz to 108MHz FM band
315MHz car keyfob
480MHz interferences
Stripes around 480MHz are because of poorly shielded USB cable
524 to 542 MHz wireless microphones
- http://www.sharebrained.com/2013/06/15/wireless-microphones-and-hackrf/
- microphone_shure.grc FM demodulator