On Tue, 2010-09-28 at 13:34 -0400, Marcus D. Leech wrote: > > > > It's likely that initialization of the board gain and frequency settings > > will take some finite but non-zero amount of time to settle. It's always > > a good idea to toss the first few samples until things settle down. The > > settling time will be different for each daughterboard and should be > > experimentally determined in your application. > > > > --n > > > > > Yup, and I'd like to point out that this isn't just a "quirk" of this > particular hardware. All such hardware takes a finite amount of time > to "settle" -- the synthesizers often take a handful of milliseconds > to settle to their final value, and even VGA settings take finite time. > > The A/D has no way of knowing what that time is, so it starts sending > samples right away--those samples will contain "artifacts" of > whatever settling has to take place. Fact of life. > > I don't know how the filters in the FPGA are coded, but it also wouldn't > surprise me if they take some finite amount of time to converge > on correct output, since they'll have some indeterminate startup state. > >
My experience is that it doesn't matter how long I wait after setting the gain and frequency. It could be FPGA filters. BR/ Per _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
