[Discuss-gnuradio] Simultaneous send and receive with USRP2 and RFX900 Daughterboard

[Pascal Sachs]

I'm trying to simultaneously send and receive a sine signal with the
USRP2 with a RFX900 Daughterboard. My setting is:

- An arbritary signal generator sends a sinus signal to RX2
- The USRP2 sends a sine signal through TX/RX to an external Scope
- The sampling rate is 1e6
- Interpolation at the sink and decimation at the source are both 100
- The center frequency is 900MHz
- I use gnuradio 3.3git-696-glae689f
- The USRP2  has the latest firmware on it

I use the following computer:
Thinkpad T41, 1.4GHz, 768MB RAM
Intel Corporation 82540EP Gigabit Ethernet Controller

The sine signal sent out by the USRP2 looks nice on the scope and has no
gaps in it.
The signal received by the USRP2 on RX2 is only once or twice visible
with some gap inbetween and then disapears completely.
Attached is a picture of the received signal and the code I used.

When I only receive a signal without sending, the signal looks nice.
Only sending signals works as well without any problems.

Does anyone has an idea what went wrong and/or how to fix it? Is there
any possibility to chose the antenna for transmission and reception?

Thanks for any hint and answer
Pascal Sachs

rx2_signal.png
Description: PNG image

send_and_receive.py
Description: Text Data

signature.asc
Description: Dies ist ein digital signierter Nachrichtenteil