I am looking for ideas to come up with something cheap to generate a 12V 1000Hz 20% duty cycle signal. I have tried with a 555 timer but I would have to use potentiometers which I would like to avoid. The trial circuit I built was only 918Hz with 22% duty cycle. I’d like to be within +- 10 Hz but I should be ok with +- 2o Hz. Ideally I’m trying to come up with something that I don’t need to fine tune with a scope and is cheap.