hi,

rather stupidly i sold my inverter a while back so i can't try this
out myself:

take a signal from the clock out, invert it and (stirring gently) add
it to the echo signal that is suffering from clock noise.

does it work

(another possibilty could be a delay of 1/2 cycle of the clock, if the
clock is a square wave, but we have no such delay)

anyone fancy trying it out

stu