This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-sdr@lists.osmocom.org/.
Jay Salsburg jsalsburg at bellsouth.netWell, this is interesting. Think out of the box. Ask yourself if a 8 bit NFM is high fidelity. I do high fidelity; 6 channel, 24 bit Wav files, that is high fidelity. When you have high conversion rates and high bit depth signals you get high fidelity. Audio NFM signals are only meant to satisfy walky-talky radio communication (Trunk Radio). The high value targets in Radio technology today is Data Services. Look in the (Data Stream) Mine for the Gold, Data is Gold. Data is wideband, multiple channel, and frequency diverse (not NFM), then there are all those wideband RADAR Signals. With high fidelity conversion you do not need anti-aliasing. Anti-Aliasing is a technique to filter, the very word means to take something away. Data services count on the fact that the Data is difficult to intercept. The object of any great effort is to rise above all the rest. To get the most out of the Tuner the ADC must be improved. All you guys have so much to offer and you have spent so much of your time and money to get the most out of this $20 Dongle, all because the Manufacturer refuses to open Source the Chip. Jump ahead and make better use of it. Go to the next level and hack the circuit, not just the Operating Code. The most extensive effort should be in acquiring intelligence from the Either, not listening to high power squawking Police channels. This requires very high granularity, the RTL2832 is low granularity. If you want to drop in on intelligence from over the horizon, very good selectivity is required and the RTL2832 is just not that; highly selective, intentionally by design. -----Original Message----- From: osmocom-sdr-bounces at lists.osmocom.org [mailto:osmocom-sdr-bounces at lists.osmocom.org] On Behalf Of Leif Asbrink Sent: Sunday, July 08, 2012 2:29 PM To: osmocom-sdr at lists.osmocom.org Subject: Re: stroboscopic (aka equivalent time sampling) using EZCAP DVB dongle ? On Sun, 8 Jul 2012 12:30:05 -0500 "Jay Salsburg" <jsalsburg at bellsouth.net> wrote: > The E4000 Tuner offers a stepping stone into the world of SDRs. > It does the heavy lifting, significantly reducing the size, cost, and > complexity of a SDR. It does not do any programmable signal > processing, which is where SDRs are strongest. > Quantization has been left out of the discussion because the > RTL2832 is so bad at it (to conserve size and cost). The RTL2832 > hamstrings the usefulness of the E4000 significantly narrowing the > application of DSP. If you want high fidelity reception, you must > apply a high fidelity ADC. I do not understand how you think to arrive at this conclusion. The RTL2832/E4000 dongels allow superior quality demodulation of FM signals. The suppression of neighbouring channels is limited due to aliasing, but it is not bad and interference can be avoided by changing the LO frequency. There is also a mirror image but if you use Linrad you can apply the calibration procedure that eliminates image spurs. Now that AGC is eliminated these dongles allow a pretty good general purpose SDR at small cost. http://www.sm5bsz.com/linuxdsp/hware/rtlsdr/rtlsdr.htm The high fidelity reception is in no way limited by the ADC in these dongles as long as the desired signal is not much weaker than surrounding signals. (Much means 50 dB or so.) Regards Leif / SM5BSZ