Re: [Discuss-gnuradio] starting USRP basicRX pickup

[Eric Blossom]

On Fri, Apr 14, 2006 at 12:39:45PM -0700, Erik Tollerud wrote:
> 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...

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