naturerecordists
[Top] [All Lists]

Re: Wildtronics a good product?

Subject: Re: Wildtronics a good product?
From: m_pesente
Date: Sun Sep 24, 2017 9:35 pm ((PDT))
Bruce,
you write at your website that =94Gain, for an ideal 22-inch dish with a pe=
rfect parabolic shape and focus, is characterized by a curve starting at 0d=
B at 200Hz,

The Macauly Library says that: =94The diameter of a parabola determines the=
 lowest frequency sound that a parabola can amplify. If the wavelength of a=
 sound wave is greater than the diameter of the parabola, the sound wave wi=
ll not be captured or amplified by the parabola.=94

The wavelength of 200 Hz is 1,7 meters. Hence, a parabola capable of (start=
ing) amplifying at 200 Hz must have a diameter of 1,7 meters =3D 67 inches.

The wavelength of 400Hz (where you claim that your 22" dish has 6 db amplif=
ication) - is 0,85 meters =3D 33 inches.

Can you explain?

Marco




<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU