[Discuss-gnuradio] USRP at Ham Field Day

[John Ackermann N8UR]

I took my USRP out to my radio club's Field Day site this weekend (an
annual ham radio event where we set up and operate under emergency
conditions from portable locations) and decided to play around.

I loaded Chuck's hfexplorer_9a program and hooked the BasicRX port to a
40/20 meter dipole antenna, about 25 feet up in the air.  I had no idea
what to expect with essentially no front end, but I was pleasantly
surprised that I could copy quite a few stations on SSB and CW.  Of
course, any time any of the transmitters at our site went on the air
(even on 2M), the received signal was squashed!

The experience has made me curious to see just what the sensitivity of
the system is with no filtering or preamp, so I'll hook a signal
generator up to see what it can hear in the lab.  But from the field
experience, I'm guessing that it was hearing signals in the 100uV range.

Good job on the hfexplorer software, Chuck!  Just a couple of
suggestions:  (a) trying to tune in broadcast stations on AM resulted in
horrible distortion -- sounds like extreme overload and clipping; (b)
the skirts of the bandwidth filter seem to be quite broad; maybe more
taps would give better performance, and (c) it would be nice if you
could select bands (or center frequencies) from the GUI without having
to exit the program and restart.

John