[Discuss-gnuradio] Unable to tune USRP/DBSRX

[Praveen Vikram]

Hi,

I am trying to use the DBSRX daughterboard with a USRP1.

I have tried several things to tune it to a certain frequency but nothing seem to work.

1) I used usrp_fft.py and it starts saying "Unable to set Initial frequency" in the status bar.

2) I tried usrp_rx_cfile.py like this:

         usrp_rx_cfile.py -g 94 -d 8 -R a -f 1.57542G -N 100M op

and it gave me the following output:

Using RX d'board A: DBS Rx

USB Sample Rate 8M

Failed to set frequency

3) Then I tried writing a small python script myself which was essentially:

        self.src0 = usrp.source_c(0,8);

        subdev_spec = usrp.pick_rx_subdevice(self.src0)

        self.src0.set_mux(usrp.determine_rx_mux_value(self.src0,subdev_spec))

        subdev = usrp.selected_subdev(self.src0, subdev_spec)

        subdev.select_rx_antenna('DBS Rx')

        b = subdev.set_gain(104)        

        a = self.src0.tune(0,subdev,fc)

        print "ADC freq: "+repr(self.src0.adc_freq())

        print "Decim:    "+repr(self.src0.decim_rate())

        print "Daughterboard: "+subdev.name()

        print "\t Freq Range: "+repr(subdev.freq_range())

        print "Set gain to 104db: "+repr(b)

        if a:

            print "true"

        else:

            print "false"

And I got the following output:

ADC freq: 64000000

Decim:    8

Daughterboard: DBS Rx

Freq Range: (500000000.0, 2600000000.0, 1)

Set gain to 104db: True

false

I am unable to set the frequency to anything in the given range for the daughterboard.

When I turn on the USRP, the green light on the board close to the USB port blinks fast. Once I run a script using the USRP it starts blinking slower. 

But the script doesn't complete either. (i.e if I use the usrp_rx_cfile.py, it would hang after printing the first two lines of the output I have pasted above. After which I have to press Ctrl+Z and then run sudo kill -9 <ps#>).

After which every time I run a program that uses USRP, I am unable to set the center frequency.

 

I'am using GNURadio 3-3.0 on Ubuntu 10.04 with linux kernel 2.6.32.

I'am not sure if I am doing something stupid or there is something wrong with my daughterboard. I'am out of ideas at this point and any help will be appreciated.

Thanks,

Praveen