Hi Meir,
Can you please specify your Clock frequency.
Assume your clock frequency is " Y "
And your output frequency is "X"
At this case you will get the spurious of combination (m*X) ± (n*Y)
Where n & m are positive integers.
For Your case the generated spurious may be equal to your output frequency. ie, 200MHz.
Bust in case of 201MHz Your output frequency is offset by 1MHz. that's why your are getting spurious at 1MHz Spacing.
I am attaching one MS Excel sheet with this for your reference.
Regards,
Durgesh.R