[Amps] muffin fans

2 2@vc.net
Thu, 25 Jul 2002 03:53:01 -0700

>In the vein of the B-36, kind of anyway--doesn't the helicopter make a
>beating sound with the air from the pressure side of the rotor against the
>tail assembly?

The beating sound from a helicopter comes from the sound of the rotor 
tips approaching the speed of sound.  // Off topic tidbit:  The rotor 
tips move so fast that, with an IR night video, air-friction heating at 
the rotor tips causes them to appear as light sources.  

>On the noise making--my fan bearings  make noise--the air moving through
>about everything makes noise, and especially the air moving through the
>small expanded metal screen (for sheilding) between the tube enclosure and
>the rear of the compartment. I use a 4 in. muffin fan of suspect parentage,
>120 volt, for a 2x813 amp, it's a little noisy, but lower then the summer
>QRN from the reciever, so it gets used.    Way less the the air conditioner
>blowing in my face from 3 ft away.
>W5SET steve

-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,