On Sun, Feb 19, 2012 at 03:19:21PM -0500, Marcus D. Leech wrote:
> So, on a related topic, how do commercial FM-MPX receivers maintain
> proper balance between
> L-R and L+R -- do they just have a gain control that they tweak at
> the factory and glue in place?
>
> If the gain balance is off,
GoMo News
February 13, 2012 Monday 12:43 PM EST
Warning of increased GSM + TETRA attacks
LENGTH: 471 words
Rating: We're back to Squidgygate and police radio scanners again
Here's a bit of an ominous warning. Much worse than mere voicemail hacking.
Greg Jones, a director of wireless securit
On Sat, Jun 11, 2011 at 07:40:54PM +0300, Patrik Tast wrote:
> Hi All,
>
> As you all know, VCM is short for Variable Coded Modulation.
>
> As I have read on your forum, the new DVBS-2 NOAAPORT transmission is
> variable.
> So far I have noted that users use 8PSK demodulation and FEC?.
> FEC?,
On Mon, Oct 12, 2009 at 11:16:11AM +1300, Richard Clarke wrote:
> Hi All,
>
> I was wondering if anyone has had any issues with the interpretation of
> shorts by the GNU Radio udp source function, when the shorts are
> transmitted from a big endian based platform? In my situation I am
> transmitt
On Fri, Sep 25, 2009 at 12:00:34AM +0400, Alexander Chemeris wrote:
> Power will be taken from USRP 6V, clock output will be SMA to
> connect to USRP directly. Frequency control will be accessible
> over RS-232 (aka COM-port) with simple text-based protocol. We're
> going to use ATMega for this. Id
On Sat, Apr 04, 2009 at 11:16:42PM +0500, Sajjad Sarwar wrote:
> I am doing my UG project on "optimized packet radio" in SDR. Presently, I am
> using costas loop block but i think it's recovering only the frequency of
> local oscillator but not the phase. Please correct me if i am wrong. Now the
>
On Mon, Feb 16, 2009 at 08:30:26PM -0800, Firas Abbas wrote:
> Hi,
>
> > On Tue, 2/17/09, George Nychis wrote:
>
> > Hello, Tianning/Bill/Daniel!
> >
> > The performance of 8PSK matches pretty similarly to 16-QAM.
> > So, 8PSK is usually never used in a real system as you get
> > better spectr
On Fri, Mar 21, 2008 at 04:23:00PM -0500, Rick Parrish wrote:
> Jeff Brower wrote:
> >All the standardized codecs that I know of, both ones with IP rights
> >requirements and free ones, provide a reference design, typically
> >fixed-point C code plus test vectors. I wonder why DVSI has not done
On Wed, Mar 19, 2008 at 07:38:13PM -0500, Rick Parrish wrote:
> Jeff Brower wrote:
> >If you're looking at low bitrate codecs for GNU radio, why use a
> >hardware (dongle)dependent solution? You might look at MELPe, which
> >provides 600, 1200, and 2400 bps,and can be implemented as a software
>
On Fri, Jan 11, 2008 at 06:46:46AM -0800, Johnathan Corgan wrote:
> David I. Emery wrote:
>
> > A hack I have thought about adding to the USRP FPGA code (but not
> > implemented yet) would allow collection of the count in a
> > continuously rolling 64 MHz counter driv
On Thu, Jan 10, 2008 at 08:46:09AM -0600, LRK wrote:
>
> While the 'right' fix would be to supply a stable frequency source to
> the USRP, it would be difficult.
Not impossibly difficult... it would, however, have been nice to
have a VCXO option for the USRP-1 that would have allowed exte
On Mon, Nov 26, 2007 at 11:18:53AM -0700, Chuck Swiger wrote:
> Quoting John Clark <[EMAIL PROTECTED]>:
>
> >John Gilmore schrieb:
> >>I can already think of one use that others can make of your
> >>transmitter. EFF and I are interested in measuring the DRM responses
>
> I am interested in a dvb
On Tue, Aug 14, 2007 at 10:55:40AM -0400, Vijay Ramasami wrote:
> Thanks for the information David. I will look up ITU-J.83B ...
>
> Do you happen to have any captured QAM cable data (or any website that
> lists the data) ? I wanted to see if I can put together a software
> demod for digital cable
On Mon, Aug 13, 2007 at 10:52:54AM -0400, Vijay Ramasami wrote:
> Hi,
>
> I have a couple of questions:
>
> 1. Does the US digital cable system follow the DVB-C standard (or one
> of its annexes) ? Is there any information (website) on the typical
> symbol rates, bandwidths (I am guessing approx
On Mon, Mar 12, 2007 at 10:45:14AM -0700, Johnathan Corgan wrote:
> This is typically call Automatic Frequency Control and shortened to AFC.
>
> Accomplishing AFC is modulation specific; in GNU Radio one typically
> builds a flow graph that incorporates AFC by using an appropriate
> phase-locked
On Tue, Feb 27, 2007 at 11:01:58PM -0800, Matt Ettus wrote:
>
> >(which makes me
> >curious, does anyone use non-differential 8PSK?).
> >
>
> Yes, satellites often do.
I might add that non differential PSK/QPSK has a theoretical
noise advantage if some mechanism exists to figure out th
On Sat, Oct 14, 2006 at 02:06:01PM -0400, Robert McGwier wrote:
> David I. Emery wrote:
> >
> > This implies that the USRP with a 6 to 8 mhz bandwidth might be
> >able to successfully demodulate the SCPC DVB-S QPSK video transmissions
> >at symbol rates like
On Sat, Oct 14, 2006 at 06:49:03AM -0700, Eric Blossom wrote:
> The USRP could receive the raw signals for DVB-T in the 6 and 7 MHz wide
> channel format. The 8 MHz wide version could be somewhat degraded
> because of filter rolloff at the edges of the passband of the digital
> downconverter in th
On Wed, Sep 13, 2006 at 10:05:56AM -0400, Marcus Leech wrote:
> >>There are double pulses that I'm seeing, with variable timing between
> >>the main pulse
> >>and the sub-pulse. The other 1350Mhz radar is much further away from
> >>me, but
> >>perhaps the "sub pulses" I'm seeing are coming from
On Tue, Sep 12, 2006 at 08:01:51AM -0400, Marcus Leech wrote:
> David I. Emery wrote:
> >
> > The transponders are 1090/1030 mhz and not 1350. 1350 is just
> >radar.
> >
> There are double pulses that I'm seeing, with variable timing between
> the
On Mon, Sep 11, 2006 at 11:30:47PM -0500, Rick Parrish wrote:
> *giggle*
>
> Marcus ... that's an aircraft transponder. Except for some vintage
> 1930's aircraft that don't have an electrical system - every plane /
> helicopter has one. Hit Google or Yahoo! for "Mode-C" and "Mode-S"
> transpond
On Fri, Jun 02, 2006 at 10:30:36AM -0700, Matt Ettus wrote:
>
>
> Just read about MovieBeam on Slashdot. They mention that it
> "piggybacks" on a PBS signal. I assume they mean a digital TV channel,
> but they have a very small antenna.
While I have no specific inside information at
On Sun, Mar 05, 2006 at 12:03:33PM -0800, Eric Blossom wrote:
> Good question. I've wanted to revisit it myself too.
> As I recall it was to reduce the spurs in the DDC output.
> If you get a chance, please see if you can find relevant papers.
> I suggest searching for "DDS spurs", or something li
On Sun, Mar 05, 2006 at 05:53:44PM -0800, Eric Blossom wrote:
>
> In the FPGA, the phase word (not the accumulator) is approximately
> 15-bits wide. This gives worst case phase-truncation spurs of -90 dBc.
> This looks small enough that we can safely ignore it. Therefore,
> I suggest we stop tru
On Tue, Dec 06, 2005 at 04:34:34PM -0800, Matt Ettus wrote:
>
> DBS small satellite dish systems often have LNB feedhorns capable of
> multiple polarizations and/or multiple bands. This is often controlled
> by changing the voltage which powers the device. However, some have a
> more complex con
On Wed, Nov 30, 2005 at 05:12:11PM +1030, Daniel O'Connor wrote:
> On Wed, 30 Nov 2005 16:33, Matt Ettus wrote:
> > A useful application would be to control a calibrated noise source and
> > measure the power in a given bandwidth with it on and off. This is how
> > a noise figure meter works.
>
>
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