[time-nuts] Thunderbolt mounting
Hal Murray
hmurray at megapathdsl.net
Fri Jul 13 07:14:53 UTC 2012
saidjack at aol.com said:
> We deal with big fans all the time, viz. Turboprop engines running at up to
> 2000rpm. Generates nasty massive spurs below 100hz.
2000 / 60 is 33.333 Hz
One man's noise is another man's signal. (Or something like that. I think I
picked it up here, ages ago.)
How hard is it to measure the RPM of the engine if I give you the signal from
an airplane? (If they want to find you, the radar signal is readily
available. R^4th is ugly.)
--
These are my opinions. I hate spam.
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