One thing I have always wondered is how pulsing an oscillator generator at a certain frequency but doing it in a super short time of several micro seconds actually sets up a range of frequencies. From what I remember it had to do with the pulse being so short that the no fundamental frequency was set up but that it also had something to do with the Heisenberg Uncertainty Principle. I am having a hard time understanding what the HUP has to do with it?

Regards,
Caleb