USRP1 warning "requested RX frequency is outside of the system range, requested RX frequency is outs


Sorry if I have too much question, I am getting started with GNU radio,
I did not find the answer for this on the Internet.

I have USRP1 and inside it has 2 daughter boards: WBX and RFX400.
I run the FM receiving grc file and got this

UHD Warning:
Tune Request: 102.500000 MHz
The ification:
Target Frequency: 102.500000 MHz
Clipped Target Frequency: 380.000000 MHz
The RF LO does not support the requested frequency:
Requested LO Frequency: 380.000000 MHz
RF LO Result: 400.000000 MHz
Attempted to use the DSP to reach the requested frequency:
Desired DSP Frequency: 20.000000 MHz
DSP Result: 20.000000 MHz
Successfully tuned to 380.000000 MHz

I changed various frequency and figure out the range that has
tuned is from 380Mhz to 520Mhz.
I don’t know why this happen, the WBX suppose to have range from 50Mhz
2200Mhz. Does it come from the wrong firmware ?
And moreover, my USRP has 2 daughter board, so how can I choose exact
daughter board to use ? In UHD USRP source of GNU radio. only have
for antenna port for example RX2 or TX/RX, right ?

Best regards,

On 08/14/2015 06:21 AM, Hoang Nguyen T. wrote:

The ification:

Discuss-gnuradio Info Page
The UHD source includes a “subdev specification”.

If your WBX is in the first slot, you’d use:


If your WBX is in the 2nd slot, you’d use:


As the subdevice specification.

You can use:

uhd_usrp_probe --args “type=usrp1”

To get a listing of the device configuration, including which slot your
WBX and RFX2400 cards are in on the USRP1.

Hi Hoang,

the 380MHz is the lower frequency you can get with a RFX400. That’s

You can chose your daughterboard by using the number of channels
argument (if you want both), or the subdev spec [1], like:
to select the WBX in your second slot.

Best regards,

[1]USRP Hardware Driver and USRP Manual: Configuring Devices and Streamers

Thank you,
Now it works with exact frequency .

On Fri, Aug 14, 2015 at 9:35 AM, Marcus Müller
[email protected]