Inconsistent Phase on Startup

What is the application ?

Can you please share  the setup diagram that you are following? 

devinthompson said:

I am comparing the phase between Tx1 and a signal generator outputting a continuous wave.

Why do you want to compare the the phase between the TX and Signal generator ?

I would like to confirm that the relative phase between the two is consistent between initializations. I am following Figure 66 from the user guide with the only difference is using an oscilloscope instead of a VNA to compare the relative phase between the TX and Signal generator. I would like to recreate the plot in Figure 68.

My current GUI settings are as shown below. I am transmitting a tone with a 0MHz offset from the RF LO.

I would like to confirm that the relative phase between the two is consistent between initializations. I am following Figure 66 from the user guide with the only difference is using an oscilloscope instead of a VNA to compare the relative phase between the TX and Signal generator. I would like to recreate the plot in Figure 68.

My current GUI settings are as shown below. I am transmitting a tone with a 0MHz offset from the RF LO.

Are you giving the same REF_CLK input source to both the eval boards? If yes, connect the REF_CLK output to the oscilloscope and also the TX1 outputs of both the eval boards, and then check the phase of the TX channels of both the boards w.r.t the REF_CLK signal.