Re: [Discuss-gnuradio] two channel rx phase relations

[Chuck Swiger]

At 09:03 AM 9/14/2005 -0700, Eric Blossom wrote:

> On Wed, Sep 14, 2005 at 10:47:01AM -0400, cswiger wrote:
>
> > Two channels input (mux = 0xf0f0f1f0) - can the two
> > DDC be phase locked or sync'd ? The phase between them
> > appears to jump about at random after a
> >
> > chan0.set_rx_freq(0,-freq)
> > chan1.set_rx_freq(1,-freq)
> >
> >
> >
> The phase changes because the two set_rx_freq are not atomic with
> respect to each other.  It might be possible to disable the given Rx
> or Tx side of the USRP, set both of them, and then reenable.
>
> A quick look at usrp_basic.h reveals that I have not exported the
> (currently) protected methods set_rx_enable, rx_enable, disable_rx and
> restore_rx or the corresponding methods on the tx side.   Let me take
> a look at that.

Ok, if src = usrp.source_c(0, 128) )  then is the above what src.start()
and src.stop() are? I see usrp_basic_rx::start () has references to
set_rx_enable, etc.   It seems to be working.

--Chuck


        self.dut_out.stop()
        self.dut_out.set_rx_freq(0, -self.frequency)
        self.dut_out.set_rx_freq(1, -self.frequency)
        self.dut_out.start()