osmocom-sdr March 2012

osmocom-sdr@lists.osmocom.org

17 participants
15 discussions

Re: OsmoSDR sensitivity
by Dieter Spaar 06 Mar '12

06 Mar '12

Hello Christian, On Tue, 06 Mar 2012 17:49:02 +0100, "Christian Daniel -- maintech GmbH" <cd(a)maintech.de> wrote: > > The RX is not a sensitivity-wonder. Perhaps a preamp? I have to correct my previous posting, the Funcube has an LNA between antenna and the E4000 so the sensitivity numbers are not comparable. But maybe it is possible to use a similar circuit. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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Re: OsmoSDR sensitivity
by Dieter Spaar 06 Mar '12

06 Mar '12

Hello Christian, On Tue, 06 Mar 2012 18:59:35 +0100, "Christian Daniel -- maintech GmbH" <cd(a)maintech.de> wrote: > > your package is still laying here... sorry... :((((((( (head -> desk) No problem, thats why I have looked for this USD 20 device ;-) Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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Re: OsmoSDR sensitivity
by Dieter Spaar 06 Mar '12

06 Mar '12

Hello Christian, On Tue, 06 Mar 2012 17:49:02 +0100, "Christian Daniel -- maintech GmbH" <cd(a)maintech.de> wrote: > > The RX is not a sensitivity-wonder. Perhaps a preamp? According to the Funcube Technical FAQ: Each unit is tested for 0.15uV for 12dB SINAD NBFM at 145MHz and 435MHz I am not 100% sure how to compare this number with your results but this seems to be (much) better (if my quick calculation wasn't totally wrong). Also from my very short and quick experience with a DVB-T Stick based on an E4000 and RTL2832U, the sensitivity is quite good (I only tried DAB/FM/DVB-T so far with a very bad antenna inside a building). BTW, according to a newsgroup post this device also offers some sort of raw mode with around 2 MHz sample rate for 8-bit I/Q values. Not that bad for USD 20 including shipping ;-) Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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OsmoSDR sensitivity
by Christian Daniel -- maintech GmbH 06 Mar '12

06 Mar '12

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi guys, I measured the sensitivity of our OsmoSDR. For that I did the following commands: tuner.init! tuner.freq=465000000 tuner.dc_calib! tuner.dc_table! tuner.gain=6,9,9,2,15,15 tuner.iqofs=43,27,0,0 I did the measurements on no-so-even frequencies to avoid any lines in the sprectrum. I increased the power from my signal generator until a SNR of 10dB as achieved. The RX was tuned 100kHz lower than the TX signal and the I/Q offset was calibrated before every measurement. 65.2MHz: -99dBm 145.2MHz: -102dBm 435.2MHz: -104dBm 945.2MHz: -85dBm 1300.2MHz: -89dBm 1500.2MHz: -89dBm 1800.2MHz: -84dBm Also please note that we have a hole at 1200 MHz - there are no valid PLL settings here. The RX is not a sensitivity-wonder. Perhaps a preamp? Best regards, Christian - -- - --------------------------------------------------- | maintech # Dipl. Inf (FH) Christian Daniel | | GmbH ### Otto-Hahn-Str. 15 · D-97204 Höchberg | - --------------------------------------------------- | AG Würzburg, HRB 8790 Tax-ID DE242279645 | - --------------------------------------------------- | http://www.maintech.de cd(a)maintech.de | - --------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJPVj/4AAoJEHkgzUIsAWripiAIAJ00dqh1/0MEehEdQrqtN4Ox dRHJrKSv1o+2I3HlAGLXCeAYXenaML1+hrmjZfoOCz9yYDabMD65/DVplU5lnvHT nkXEkJCdkdwOL2vieb1QD0aUmgRmjH1OugOS8DotjtmtGI4Wd/nqFn39gNVSb/hZ nC06jldOeTumgzH5dxv4VbBfbuCTpm5I8ShoA7+Ub4UNSWXLUJtQRwby0xXaR23S 6KWBZAMW8wJHW8Ish9NNEdZup32ZwhpbLGDVwspHNRyxYa5YUzYQK5medVJ2K+EL dO44kX/lHU+v5SxfOhjbqjJcJWt7WQWA+L1ROIpFV8DkRMT0EscR0v1No1ybQfA= =T3tF -----END PGP SIGNATURE-----

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OsmoSDR progress
by Christian Daniel -- maintech GmbH 06 Mar '12

06 Mar '12

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello everybody, following up on Harald's great progress I wrote some tool to verify the RF purity of our design. This is the last step before we can order the final PCBs and start production. Sadly from my current results we have some room for improvements. Right now I'm reviewing the E4000 driver as I suspect the visible steps in the attached spectrum to be switching points in the E4000. Perhaps something can be improved here... Stefan told me that without any antenna the output levels of the E4000 should be below the LSB limit of the ADC - clearly we have a lot of noise on the signal. But we also don't have any I/Q calibration and I can see significant offsets on these lines... I'll keep you posted! Cheerio, Christian - -- - --------------------------------------------------- | maintech # Dipl. Inf (FH) Christian Daniel | | GmbH ### Otto-Hahn-Str. 15 · D-97204 Höchberg | - --------------------------------------------------- | AG Würzburg, HRB 8790 Tax-ID DE242279645 | - --------------------------------------------------- | http://www.maintech.de cd(a)maintech.de | - --------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJPTzeFAAoJEHkgzUIsAWrilLMH/1s45+iDzv0+YqNpql5sZSs0 88uWFZbbpd22HVY4tifMpe5n4E1bJJBK2Sfuq9t4HDIV/Tka9KijCDT7a3BVbzzQ TqQ3iimSdS7/+UYiNI9OPhdpFaBE1tuCcvWg4lBXct125mynOM/VajLMsXDd/4E6 UVtwUqFxWFXhWXi7/jT/P8+2dhUHZ0sLTsWNp7FS8+SCn7/Uu9QvEc0ZIr8ufaiK NwWTM8O16mUEn0iFMme8WdBhTsi7TTiK23Wd7RZGkZfZeMEr93jPtpvlvkDRlwiF RJC158eAZASsXfyRAw1wr59GVsJF4S7HV88LkKVFS4FOU2t09b/DKZplWnfp0IQ= =5KOA -----END PGP SIGNATURE-----

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osmocom-sdr March 2012