Re: [Discuss-gnuradio] Simultaneous TX/RX Sample Code for RFX (FLEX) 400

[Eric Blossom]

On Fri, May 19, 2006 at 11:26:54AM -0700, rdmiller wrote:
> 
> Greetings,
> 
> I am having an issue receiving signals properly using a single RFX (FLEX)
> 400.  I am using usrp_siggen.py (with a sinusoid) to transmit via "TX/RX" in
> the 450 MHz range, and have verified its functionality via a spectrum
> analyzer.  The transmitter ("TX/RX") is hardwired to the receiver ("RX2")
> via an SMA to SMA cable.  I have tried the following:
> 
> 1.  Using usrp_rx_cfile.py directly
> ==>  This results in incorrect data.
> 2.  Adding the following line to usrp_rx_cfile:
> u.select_rx_antenna(1)
> ==>  This results in an error, as the method ("select_rx_antenna") is not
> found.
> 3.  Adding the following line to usrp_rx_cfile:
> u.subdev.select_rx_antenna(1)
> ==>  This also results in an invalid method error.


# not tested, but expected to work...

self.subdev.select_rx_antenna('RX2')



> My question is whether or not any of the above tests should work.  If not,
> can someone proved some simple sample code to properly receive data using
> "RX2" of the RFX 400 while the "TX/RX" port is being used as a transmitter?

You're going to need a serious amount of attenuation (pad).
Connecting the 100mW transmitter output directly into the Rx input
port isn't going to work.

Eric