Error With GPSDO USRP x300

[Jones, James (jtjones49)]

Hello, I have a USRP x300 and I am trying to use the GPS module for clock sync. I am running Ubuntu 20 and am using external GPS antennas and am using GNUradio version 3.10.5.1 . I have the following arguments for the USRP source block:

Sync: Unknown PPS

Time Source: Default

Clock Source: O/B GPSDO

However, when running this block I get the following error:

Traceback (most recent call last):

  File "/home/.../Documents/test.py", line 290, in <module>

    main()

  File "/home/.../Documents/test.py", line 268, in main

    tb = top_block_cls()

  File "/home/.../Documents/test.py", line 92, in __init__

    self.uhd_usrp_source_0_0.set_clock_source('gpsdo', 0)

RuntimeError: RuntimeError: Reference Clock PLL failed to lock to gpsdo source.

Any help is appreciated and thank you to Marcus Müller for helping me resolve the incompatibility with the USRPs.

James Jones