Re: N310 TX with external LO

On 01/26/2021 06:26 AM, Damon qiu wrote:

Dear Madam/Sir,

     Recently, I had encountered a problem that was the synchronization of signal between the four channels of USRP N310.  For sloving this problem, I used to the mode of external local oscillator (LO) of N310. As this article says (https://kb.ettus.com/N300/N310),  a power divider was used to LO inputting signal into two channels. The amplitude of two channels of LO input was about 3dBm. The LO input frequency was twice the frequency of the desired RF output frequency. Then, the system was switched to the mode of  external LO in the GNU Radio software.

   However, no signal was be output except noise,as shown in figure 1. The figure 2 was the output signal in the modle of internal LO. Plesee help me to slove this problem!

Best regards,

Damon

What is the desired frequency?

What device argument is being used?  You should use "tx_lo_source=external" in the device argument.