Hello, Jishnu, Thank you very much for your reply. I will try your suggestion when I'll arrive at home, maybe next week. I think your reply is very helpful and is OK regarding this mailing list.
Best regards Octavian În mar., 19 nov. 2019 la 11:23, Jishnu Nambissan T <jis...@rri.res.in> a scris: > Hi Tavi, > > It would be best to use an SDR or a board like Redpitaya or SNAP that can > sample the entire band, but if you have got an RTLSDR, I can suggest a > small trick that might work (no harm in trying). GQRX might be an overkill > as you don't need the demodulation part. > I have written a small python code that uses pyrtlsdr to read some samples > and FFT them. The centre frequency is changed and the process is repeated. > The spectra are then stitched together. The code snippet is not the best > and the logic has got some bugs. Nonetheless, you can start from that and > develop. It is available at https://github.com/VU3VWB/rtlsdr_spec_analyser ; > try rtl_spec_analyser_fft_scan_3.py > > NB: This is my first time replying to a mailing list, please let me know > if there is some silly mistake (reply, reply to all etc.) > > Regards, > Jishnu > > ------------------------------ > *From: *"Tavi B" <tavi...@gmail.com> > *To: *casper@lists.berkeley.edu > *Sent: *Thursday, 14 November, 2019 08:17:31 > *Subject: *Re: [casper] heliospectroscope > > Hello, Dan, > > Thank you very much for your detailed answer. I will read the details of > suggested boards. > > So far I've try RTL-SDR, Airspy2+Spywerter and bladeRF x40+XB200 with > gqrx. But the gqrx cannot sweep and record full bandwidth at needed sample > rate. The main concern is the time of stabilization of the frequency tuned, > that's why a large simultaneous bandwidth is desired. The bladeRF 2.0 is > faster and have a large bandwidth (56MHz) and have affordable price. It is > an integrated radio with TX and filters but we would not pay for features > that we don't need. RedPitaya sounds better. > > Best regards, > Octavian > > marți, 12 noiembrie 2019, 16:13:51 UTC+2, danseti a scris: >> >> >> hi octavian, >> i don't know much about solar radio spectroscopy, >> but i think in some solar applications, the SNR is very high, >> and the time variability is slow enough that you could use a spectrometer >> with a small instantaneous bandwidth, >> perhaps 10 or 20 MHz bandwidth, and then sweep this spectrometer across >> your 800 MHz band. >> if that's the case, the spectrometer could be very inexpensive because >> you could use a GNUradio system. >> >> if you need more instantaneous bandwidth, the red pitaya fpga board has >> two 125 Msps ADC's, >> and casper has a spectrometer tutorial for this board. you might be able >> to use the spectrometer tutorial design directly, >> or modify the design for your application. the red pitaya boards cost a >> few hundred dollars. >> https://www.redpitaya.com/f130/STEMlab-board >> >> the next step up would be to use a snap fpga board, which costs about >> $3000, and has four 950 Msps ADC's. >> casper has a spectrometer tutorial for the snap board as well. >> >> >> for even higher instantaneous bandwidth, there are several casper ADC >> boards you could plug into the snap board. >> eg: single 2 Gsps ADC board, a dual 2.5 Gsps ADC board.... >> >> information on the snap board, adc boards and tutorials are on the casper >> wiki pages. >> >> >> best wishes, >> >> dan >> >> >> >> >> Dan Werthimer >> Marilyn and Watson Alberts Chair >> Astronomy Dept and Space Sciences Lab >> University of California, Berkeley >> >> >> On Tue, Nov 12, 2019 at 1:27 AM Tavi B <tav...@gmail.com> wrote: >> >>> Hello, >>> >>> I'm new in this research, in Romania there is no scientific radio >>> telescope yet. I'm working at the Solar Group of Astronomical Institute of >>> Romanian Academy and this is the reason I would start with a solar radio >>> spectroscope, CALLISTO like station. I searched an inexpensive SDR to >>> emulate the callisto analog receiver but with fairly large bandwidth and >>> speed. The high end ones are too expensive and have many features that we >>> don't need like DAC, TX, filters and so on. >>> >>> I've learned that a 12bit ADC with high Mbsp and a FPGA can do the job, >>> we don't need to decode or demodulate a signal, just record the noise level >>> coming from the Sun (or other radio astronomy objects). In this search I've >>> found your group and I wonder if you can help me to find a really cheap >>> solution because we don't have a budget for this project right now. >>> >>> What modules I can buy or build myself (I have basic skills on >>> electronics, microcontrollers and radio) to get a spectrogram of 400 MHz >>> wide with a better than 0.1s time resolution? The Sun radio burst can be >>> received between 10-1500MHz but with different antennas, so I would start >>> with a log periodic dipole wide band antenna, from 120 to 800MHz. >>> >>> Thank you and best regards, >>> Octavian Blagoi >>> researcher >>> AIRA www.astro.ro >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "cas...@lists.berkeley.edu" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to cas...@lists.berkeley.edu. >>> To view this discussion on the web visit >>> https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/68ef8ced-7318-436d-b1fd-a96db187122f%40lists.berkeley.edu >>> <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/68ef8ced-7318-436d-b1fd-a96db187122f%40lists.berkeley.edu?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups " > casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/f8a45127-569f-4467-a468-0afe53a625f9%40lists.berkeley.edu > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/f8a45127-569f-4467-a468-0afe53a625f9%40lists.berkeley.edu?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups " > casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/1969367094.1121821.1574155414399.JavaMail.zimbra%40rri.res.in > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/1969367094.1121821.1574155414399.JavaMail.zimbra%40rri.res.in?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. 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