Thanks, Jason. I should have posted our observations back when we made them. We're doing okay with the two-USRP setup, but it's good to have options.
-Marc On Mar 14, 2011, at 12:30 PM, Jason Abele wrote: >>>> However, the WBX has enough internal leakage between tx and rx that we >>>> gave up on single-daughterboard full duplex. >>>> >>> >>> Just a heads up, you had not tried WBX without C1 installed on the >>> grand-daughterboard, or even without the grand-daughterboard at all, >>> just using J202 and J201 on the main WBX board, you might see if one >>> of those scenarios could meet your tx-rx isolation requirements. >>> > > Sorry, missing and *if* in there ( ... Just a heads up, if you have not ... ) > > Basically, C1 allows for reception on the TX/RX antenna port, it > connects the two T/R switches. > > However, if you are looking to do full-duplex, you will not be > receiving on the TX/RX port anyhow, just RX2. So rather than having > an implicit leakage path through the T/R switches (RF switches rarely > give more than 20-30dB isolation, depending on frequency), you can > remove C1 on the grand-daughterboard and improve isolation at the > expense of not being able to receive on the TX/RX port. > > If you want to go even further, you can remove the grand-daughterboard > entirely and install SMA connectors in J201 and J202. You will also > need to move a capacitor to AC couple J201 and J202 to the circuit. > > Jason > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
