Drew Dalgleish wrote:

On Sun, 21 Dec 2003 17:56:56 -0500, "Ron Natalie"
wrote:


"PaulaJay1" wrote in message ...


I got a free program that uses the engine sound to give you RPM. I don't know
the web site but the program says email is . Just
take a laptop to the plane and check it out.


Engine sound or prop sound? How does it work on geared engines?

(just kidding).


Someone suggested using a street light as a strobe to check your tach.
Do the math to figure out what speed will stop the prop and see if
your tach agrees
Drew

I guess you are saying the street light flickers at 60Hz. Than a 2
bladed prop should look stopped at 1800 RPM? I might give this a try but
I think this would be better for calibrating the tach neadle rather than
the tach hour indicator.

John Roncallo