[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] USRP2 Announcement
From: |
Eric Cottrell |
Subject: |
Re: [Discuss-gnuradio] USRP2 Announcement |
Date: |
Fri, 12 Sep 2008 16:04:27 -0400 (EDT) |
----- Start Original Message -----
Sent: Fri, 12 Sep 2008 12:04:44 -0700
From: Eric Blossom <address@hidden>
To: Douglas Geiger <address@hidden>
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
> address@hidden
> 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