Back in the late sixties (Eons ago, I know) I lit off an OS pulse jet in the garage. All the dogs in the neighborhood howled for hours!
In 1970, we ran a much larger pulse jet at work in the outdoor test cell in order to evaluate it's performance for an RPV project (Ryan Aeronautical).
We did this on Saturday, hoping that we could run it when few people were in the plant. As luck would have it, the Mfg. VP, Bill Wiley was there(Unfortunately), and heard it....
We were told under pain of death "Do not ever run that Gawd Damn thing in my factory again!!!!!!!.
That was the loudest thing in the world. They used to be advertised in Popular Mechanics and Popular Science magazines as powerplants for home built helicopters. They were intended to be mounted at the end of each rotor blade, to provide a "no torque" rotor system, and eliminate the need for a tail rotor. They are not throttleable, as they rely on the flutter frequency of the reed valve to admit fuel to the combustion chamber.
Fond memories.........just thought I'd share that one with you.

Harley Condra
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