Strange thing with XCVR2450 on USRP2

GNU Radio
1

Hi,

I’m quite new to USRP2 and XCVR2450. Today, I get a new XCVR2450
combined
with USRP2. Using usrp2_fft.py, I found a notch in the center of the
spectrum, which is about 500kHz wide. And I tried an early ordered
XCVR2450
on the same USRP2, the notch disappeared and the spectrum seems normal.
However, when I switch to new frequency carriers, usrp2_fft.py and
usrp2_sig_gen.py alway report “Failed” in the down left corner. But I’m
sure
the daughterboard is indeed receiving or transmitting on the carrier
with
the help of a vector signal generator or spectrum analyzer.

Thanks in advance.

Hanwen

2

Hi Johnathan,

The XCVR2450 board with a DC notch is version 1.1 the serial number is
543.
I attached two screenshots of the usrp2_fft.py.
The XCVR2450 board which has problem of tuning is also version 1.1 with
serial number of 79.
The motherboard is version 4.0 wih serial number of 543.
The revision of GR is 11182, the last change of it was made on Wed, 10
Jun
2009.
I don’t know how to get the firmware and FPGA version. Is there a
command
line telling these versions?

Thanks a lot!

Hanwen

2009/9/8 Johnathan C. [email protected]