How to tell PSS to ignore a vpulse source

 Dear All,

I am doing a PSS/PSP analysis. I am using a vpulse at the supply node. This vpulse is meant for generating a supply step input The step starts at 2us and then sets at the supply voltage in the rest of the simulation time.

I have set the period of this source very large (T=1ms).

I have other vpulse sources which generates the periodic clocks (T=0.4ns).

But PSS is also considering the supply- Vpulse and setting the beat frequency 1K.

Is there any way of telling PSS to ignore the supply- Vpulse and set the beat frequency as per the clock-Vpulse ?

I am also trying with setting the beat period manually ie. 0.4ns.  Is this the right way ?

Kind Regards,