[EMAIL PROTECTED] wrote: > Hi all- > > can anybody explain why the USRP/ LF_RX would seem to introduce a DC > bias or offset to a signal generated by a function generator? I have > a function generator configured to produce a 1 kHz .1 V P-P signal > into a 50 Ohm load. I have a Lecroy digital oscilloscope configured > with the input at high-impedance to monitor the signal. When I > connect the signal to the USRP, I see the trace on the Lecroy gets > shifted UP by about .06 volts, ie I have to add a -0.06 V offset at > the function generator to zero the bias.
Are you sure everything is on the same ground? Disconnect everything but leave it powered up, and measure the voltage on the ground of the scope, lfrx, usrp power supply, and sig gen. Then reconnect things and do the same. > Oddly enough, usrp_oscope.py doesn't show any DC bias whatsoever, > regardless of what offset I put into the function generator. Maybe > it's removed inside the flow-graph? DC offset is automatically removed in hardware, but you can turn that feature off. Matt _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
