On 07/19/2016 04:02 AM, Giovanni Mascellani wrote: > Hi everybody. > > I am not very experienced with SDR, but I believe that my HackRF has > problems when receiving. Here is what I have tried so far: I would be > very grateful if you could tell me whether this is normal or not and > possibly other tests to understand what is going on. > > First of all, I am using an up-to-date Debian sid.
Actually, it's up to date out of date OS unless you used backports but then it may still be out of date. I believe sid is Debian 6 and the current version of Debian is 8. And I have no idea how the git version relates to the released version. I recommend you uninstall the sid version and install the latest user libraries, firmware and cpld. Download the software from https://github.com/mossmann/hackrf/releases/tag/v2015.07.2 and build the libraries and tools in the ./host directory The build instructions for the libraries are here https://github.com/mossmann/hackrf/blob/master/host/README.md To update the firmware and the cpld, use the binaries for firmware and cpld in the ./firmware directory and use these instructions to https://github.com/mossmann/hackrf/wiki/Updating-Firmware -- Cinaed The hackrf software > is the one distributed there. The HackRF One is connected directly to > the computer USB port and I am using the default antenna ANT500 shipped > with it. > > $ hackrf_info > Found HackRF board 0: > Board ID Number: 2 (HackRF One) > Firmware Version: git-44df9d1 > Part ID Number: 0xa000cb3c 0x00674352 > Serial Number: 0x00000000 0x00000000 0x457863c8 0x2563771f > > Gqrx opens it successfully and shows a plausible spectrum and waterfall > (I see very FM distinct stations, if I move to 900 and something MHz I > can see less distinct but still clear GSM channels; I can see DVB-T > channels and WiFi channels). I can tune and listen to FM stations, so > receiving works at least partly. But FM receiving is easy: the problems > begin when I try to decode something more delicate. > > For example, if I try to use kalibrate-hackrf I get inconsistent results: > > $ ./kal -g 16 -l 32 -s GSM900 > kal: Scanning for GSM-900 base stations. > GSM-900: > chan: 23 (939.6MHz + 24.296kHz) power: 166951.26 > chan: 24 (939.8MHz + 9.106kHz) power: 231138.37 > chan: 25 (940.0MHz - 23.307kHz) power: 169991.90 > chan: 26 (940.2MHz - 38.398kHz) power: 173509.28 > chan: 27 (940.4MHz - 34.286kHz) power: 169435.45 > chan: 51 (945.2MHz + 31.693kHz) power: 203465.57 > chan: 52 (945.4MHz + 37.553kHz) power: 199520.76 > chan: 53 (945.6MHz - 9.242kHz) power: 189952.00 > chan: 55 (946.0MHz - 18.520kHz) power: 219433.97 > chan: 101 (955.2MHz + 16.068kHz) power: 224264.62 > chan: 102 (955.4MHz - 8.907kHz) power: 231327.13 > chan: 103 (955.6MHz - 33.901kHz) power: 232225.30 > > For reference, here is the result of kalibrate-rtl running at the same > time on a random cheap RTL-SDR receiver: > > $ ./kal -g 38 -s GSM900 > Found 1 device(s): > 0: Generic RTL2832U OEM > > Using device 0: Generic RTL2832U OEM > Detached kernel driver > Found Rafael Micro R820T tuner > Exact sample rate is: 270833.002142 Hz > [R82XX] PLL not locked! > Setting gain: 38.0 dB > kal: Scanning for GSM-900 base stations. > GSM-900: > chan: 1 (935.2MHz + 35.902kHz) power: 152588.67 > chan: 19 (938.8MHz + 35.669kHz) power: 79649.74 > chan: 33 (941.6MHz + 35.259kHz) power: 96929.05 > chan: 34 (941.8MHz + 34.809kHz) power: 446793.20 > chan: 94 (953.8MHz + 33.924kHz) power: 95281.88 > chan: 98 (954.6MHz + 33.869kHz) power: 302184.33 > chan: 100 (955.0MHz + 33.952kHz) power: 117813.97 > chan: 106 (956.2MHz + 32.767kHz) power: 90438.32 > > Results for HackRF have erratic channel offsets and rather constant > power levels, which to me means that it is just detecting random things > that by chance pass the detection threshold. Instead results for RTL > have consistent offsets and random powers (which is sensible, since > channel power is adapted to what is actually needed and towers may be > more or less far from me). > > If I launch detection on a specific channel, RTL terminates in a few > dozens seconds with a consistent result (consistent both between > different invocations and different channels). HackRF (even when using a > channel that works with RTL) never terminates, which I think means that > it never finds any good reference. > > What do you think about this? Do you have any suggestions? > > Thanks, Giovanni. > > > > _______________________________________________ > HackRF-dev mailing list > [email protected] > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev > _______________________________________________ HackRF-dev mailing list [email protected] https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
