[Laser] PWM of LED in QST

[Tim Toast]

I had read somewhere while looking at the PWM circuits recently that you should only use half of the total pulse width range when generating AM. So you wouldn't use the full range of 1/99 to 99/1 as you do when controling motors - Is that true?

In other words, with the strongest modulation, the pulse width might vary from duty-cycle 25/75 to 75/25. But it could also be set to use 10/90 to 60/40. Or it might use 40/60 to 90/10 and still have full modulation?

Would using the full (or almost) range of duty cycles cause some distortion of the AM detected in a receiver?