I’m still in the exploring phase of my GNU radio work and currently ran
an annoying problem. All I want to do is transmit AM from one USRP to
another, which I thought would be the simplest RX/TX chain I could come
with for a start.
However, I have not managed to get a clean AM reception with a USRP. I’m
pretty sure the tx component works, because I can listen to my
with an old kitchen radio and it sounds fine.
RXing with the USRP simply doesn’t work, though, neither with
nor with anything I could come up with. I get lots more noise than
and usually I get a very loud buzz or whistle which is a lot louder than
TXed signal. Has anyone else had this problem?
I’m using the Basic* boards directly connected to an antenna (no
filtering). I realize this is not how the BasicRX is intended to be
can this be the cause of a loud buzz or would it only create lots of
noise? Basically, is this a completely futile attempt?
I also tried the TVRX and then I sometimes get some spectral lines
40kHz next to my main signal (this frequency doesn’t occur anywhere in
chain, it’s audio at 32kS/s interpolated to 320kS/s for the USRP). My
on the TX chain seem OK, at least I haven’t seen those spectral lines on
(external) spectrum analyzer. Has anyone else ever seen lines like this?
Thanks for any help,
Institut fuer Nachrichtentechnik