Chuck, I'm pretty sure you are aware of it -- that's the bases of some Phased-Array antennas -- I'm woking on this subject albeit its not related to USRP but your experiment could be the starting point for this kind of venture...
Good job, Angilberto. --- Robert McGwier <[EMAIL PROTECTED]> wrote: > Chuck that is sweet. Nice work. > > Bob > N4HY > > > > Chuck Swiger wrote: > > > This weekend's project was pretty easy and useful. > My indoor antenna > > is a loop > > with pretty sharp Q which requires touching up, > manually, even if > > receiver frequency > > is changed only 50kHz. I have to get up, walk over > to the loop and > > turn a 365pf variable > > cap to 'peak' the signal. > > > > I just found out about MVAM109 varactors, which go > from about 40 - 400 > > pf with > > 0-9vdc bias, so it was fairly easy to use the > gnuradio/usrp aux DAC > > 'D', the sigma > > delta, which is brought out on J17 on the basic RX > board, and makes > > 0-3.3 vdc > > with 12-bit precision, a 2N2222 transistor dc amp > with a 12v supply to > > boost it > > up to 0-9vdc. Put two MVAM109's back to back on > the loop fed thru 100k > > resistors > > (they're very high Z) and now I can adjust and > peak the antenna with a > > slider on the gui ;)) > > > > --Chuck > > > > http://partsandkits.com/MVAM109.pdf > > src.write_aux_dac(0,3,value) 0<value<4095 > > > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > -- > AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, > Packrats > Laziness is the number one inspiration for > ingenuity. Guilty as charged! > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio