Say Enter "RTL readlen=524288" in the 'ExtIO : Device hint' edit field, when that is what you mean
OK I get it. I wish those who write this stuff were not so Cryptic and Acronymous. On this page ... http://wiki.spench.net/wiki/USRP_Interfaces the author has an entry that looks like this "RTL readlen=524288" yet nowhere in the immediate text is there any language stating to enter this text in the 'ExtIO : Device hint' edit field, you have to sort of guess the author thoughts. No one is ever thinking like the one who is doing the original thinking so to reproduce original thinking adequate references to what the author is thinking is required to reproduce the original thoughts in the reader's mind. Literate illustration makes everything so much easier (and a liberal sprinkling screen shots). Thanks Jay Salsburg
quick question concerning the RTL2832U ADC: is it 7 bit (as stated on the Realtek web page in the cryptic "7-bit ADC for RF signals level measurement" or 8-bit as stated on the osmosdr web page ? or is it 7 bit + sign = 8 bits ? I am computing the gain from oversampling wrt a sound card, and not that it matters much but I'd rather have the figures right. Thanks, JM
Hi,
quick question concerning the RTL2832U ADC: is it 7 bit (as stated on the Realtek web page in the cryptic "7-bit ADC for RF signals level measurement" or 8-bit as stated on the osmosdr web page ? or is it 7 bit + sign = 8 bits ?
8 bits AFAIK. The "7-bit ADC for RF signals level measurement" is most likely just an RSSI measurement ADC. Cheers, Sylvain
another question: all my attempts at recording signals from satellites (NOAA POES weather satellites and ISS) have so far failed. For NOAA, I can sometimes get a faint signal, but nothing worth decoding to get a weather map (even with a 25 dB LNA preamp). Now, I have found one web page (cannot remember where) associating the poor receiver sensitivity to the RTL2832U DAGC. I remember seeing on this list that someone had managed to disable this DAGC, but is this functionality avaiable in the gnuradio gr-osmosdr block ? As an option provided to the gr-osmosdr block ? should the DAGC value be set to some specific value then ? Or kept at minimum value ? Thanks, JM
Hi, On 17.08.2012 09:09, friedtj@free.fr wrote:
all my attempts at recording signals from satellites (NOAA POES weather satellites and ISS) have so far failed. For NOAA, I can sometimes get a faint signal, but nothing worth decoding to get a weather map (even with a 25 dB LNA preamp). Now, I have found one web page (cannot remember where) associating the poor receiver sensitivity to the RTL2832U DAGC. I remember seeing on this list that someone had managed to disable this DAGC, but is this functionality avaiable in the gnuradio gr-osmosdr block ?
The DAGC is disabled by default in current librtlsdr, so if you use a recent version you should have no problems. In fact, my reception was fine when I tried it (even without LNA). See http://rof.li/pic/groundplane/ Regards, Steve
wonderful pictures. What NFM settings do you use ? surprisingly I had better results with excessively narrow settings (5 kHz bandpass, 1 kHz cutoff bandwidth) compared to the expected 45 to 50 kHz wide setting expected for this mode. I am leaving mid-september for some remote northern area and would love to take the EZCAP with me to demonstrate satellite reception using lightweight equipment (as opposed to a dedicated receiver + car battery). JM ----- Mail original ----- De: "Steve Markgraf" <steve@steve-m.de> À: osmocom-sdr@lists.osmocom.org Envoyé: Vendredi 17 Août 2012 10:36:20 Objet: Re: gr-osmosdr disable RTL2832U AGC ? Hi, On 17.08.2012 09:09, friedtj@free.fr wrote:
all my attempts at recording signals from satellites (NOAA POES weather satellites and ISS) have so far failed. For NOAA, I can sometimes get a faint signal, but nothing worth decoding to get a weather map (even with a 25 dB LNA preamp). Now, I have found one web page (cannot remember where) associating the poor receiver sensitivity to the RTL2832U DAGC. I remember seeing on this list that someone had managed to disable this DAGC, but is this functionality avaiable in the gnuradio gr-osmosdr block ?
The DAGC is disabled by default in current librtlsdr, so if you use a recent version you should have no problems. In fact, my reception was fine when I tried it (even without LNA). See http://rof.li/pic/groundplane/ Regards, Steve
Hi, On 17.08.2012 08:35, friedtj@free.fr wrote:
quick question concerning the RTL2832U ADC: is it 7 bit (as stated on the Realtek web page in the cryptic "7-bit ADC for RF signals level measurement" or 8-bit as stated on the osmosdr web page ? or is it 7 bit + sign = 8 bits ?
8 bit, the "7-bit ADC for RF signals level measurement" is the RSSi-ADC than can be used to measure the signal power as reported by some tuners. Regards, Steve
participants (4)
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friedtj＠free.fr -
Jay Salsburg -
Steve Markgraf -
Sylvain Munaut