250MHz signal generation using Basic TX

Hi,

Greetings.

I have an USRP Rev-4.5 board, which contains two daughter boards, Basic
TX
and BasicRX. According to the TX and RX Daughterboards data sheet, the
TX
daughter board is capable of generating up to 1 MHz to 250 MHz signal.

I am unable to generate transmit signal more than 44MHz using the
usrp_siggen.py program which comes with the Gnu Radio software
development
kit to generate the Transmit signal.

Appreciate if anyone could provide instructions for generating the
frequency
up to 250 MHz as well instructions for using the external clock for the
usrp
board.

Thank you in advance.

Best Regds,
Sudhir.

On 03/29/2010 08:11 PM, S’dir wrote:

kit to generate the Transmit signal.
The DAC rate is 128 Msps. Technically, you cannot have frequencies above
the nyquist rate of 64 MHz. The basic tx relies on aliasing to get
anything above that rate. Take a look on a spectrum analyzer when
transmitting, you should see the signal and its aliases. -Josh

Thank you Josh,

Appreciate if you through a light on “the instructions for using the
external clock for the usrp board”

Thanks & Regds,
Sudhir.

http://gnuradio.org/redmine/wiki/gnuradio/USRPClockingNotes