----- Start Original Message ----- Sent: Fri, 12 Sep 2008 12:04:44 -0700 From: Eric Blossom <[EMAIL PROTECTED]> To: Douglas Geiger <[EMAIL PROTECTED]> Subject: Re: [Discuss-gnuradio] USRP2 Announcement
> On Fri, Sep 12, 2008 at 01:54:08PM -0500, Douglas Geiger wrote: > > Very exciting! > > > > One technical question: > > By 25 MHz of instantaneous RF bandwidth - do you mean the 100Msamples/s > > from the ADC gets decimated down to 50Msamples/s? In which case, is the > > Gig-E able to handle that much sustained throughput (I'm guessing that's > > with 8-bit samples?). > > 100MS/s I & Q is decimated to 25MS/s complex. We use 16-bit I & Q. > That works out to ~800Mbit/s on the gigabit ethernet, which the USRP2 > can sustain, no problem. > > > Also, does the locking of the clocks of multiple USRP2's work like the > > USRP, e.g. where I can set one as the master and the other as slave - i.e. > > is the MIMO cable you refer to a coax SMA-SMA cable to connect the clock > > in/out connect (which have to be soldered in place) and the 2-wire cable to > > the daughterboard (like described on > > http://gnuradio.org/trac/wiki/MultiUsrp)? > > No soldering required. The mimo cable is a serial attached scsi cable > repurposed for our needs. The host configures the clocking on the > USRP2s over the ethernet. > > Here are the clocking options: > > USRP uses it's own free running xtal oscillator > USRP uses the external reference input (SMA connector) > USRP uses the clock provided over the MIMO cable. > > In addition, the master is programmed to drive clock onto the > MIMO cable. > > Eric > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > ----- End Original Message ----- Hello, Is 14 bits good enough to do HF receive without doing special gain control or filtering? I assume that I could take the whole HF spectrum, output it at 15 MSPS, and only need 480Mbit/s of ethernet bandwidth and 60 MBytes of disk space per second of recording. I could put about 1-1/2 minutes of HF spectrum on a single layer DVD-R. I guess I need that Blu-Ray drive now. I ordered one today and I hope I get it before I leave for the DCC. The case alone looks neat. 73 Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
