I can't seem to find a consistent answer to this - I'm trying to test my USRP now that I have the software working correctly, but I can't seem to find much anything in the FM or AM bands (usrp_wfm_rcv and/or usrp_fft) using the antenna that I bought with the USRP (the "144MHz, 430 MHz, 1200 MHz Tri-band 6-inch vertical antenna" one), or just various lengths of wire I tried hooking in. It does seem to lock in a bit around 100.1 MHz (although I don't think that's a radio station in the vicinity), but there's no audio coming out the demod. So should I expect to be getting anything without any RF front end? Oh, and I'm in Tacoma, WA, so there are a number of fairly strong radio stations around...
on 2006-04-14 21:41
on 2006-04-14 23:18
On Fri, Apr 14, 2006 at 12:39:45PM -0700, Erik Tollerud wrote: > around... With no gain or selection in the front end, it's pretty hard to see anything. However, if you use a 75cm piece of wire as an antenna, there's a pretty good chance you'll be able to pick up broadcast FM stations. Note that because we sample at 64 MS/s, when using the basic rx you can't distinguish 96MHz + N from 96MHz - N. Try running usrp_fft.py and seeing what you see. You'll probably have to turn the gain all the way up. The "right answer" is to use one of the daughterboards that actually contains a tuner. E.g., TV RX, Flex 400, Flex 2400. Eric