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## Re: Edmund Parabolic Reflectors

 Subject: Re: Edmund Parabolic Reflectors Gregory Kunkel <> Wed, 4 Aug 2004 14:54:03 -0700 (PDT)
 ```If the manufacturer chooses to make a parabalic dish with a diameter equal to 4 times the focal length he must make the depth equal to the focal length. That is unless his factory is in a different dimension. Greg Kunkel --- Mike Feldman wrote: > Gregory Kunkel wrote: > > > The math of parabolas states that the width of a parabola at > the > > level of the focal point is 4 times the focal point. So each of > the > > parabolic dishes have a depth equal to its focal length. > > That's true given the assumption that the design happens make the > depth of the dish equal to focal length, but there's nothing > mathematical forcing the manufacturer to this constraint. > > > So the 18" has a depth of 4.5" and the 24 inch has a depth of 6". > > That being said, the Edmund dishes are in fact as deep as their > focal length, and my 24" diameter dish measures 6" deep. It seems > to me that there was some discussion here or on a related list > about the Telinga dishes being deeper than their focal length, > and that's important for sound reflectors more so than for > optical reflectors. > > -- Mike > > > ------------------------ Yahoo! Groups Sponsor > --------------------~--> > Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. > Now with Pop-Up Blocker. Get it for free! > http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/PMYolB/TM > --------------------------------------------------------------------~-> > > > "Microphones are not ears, > Loudspeakers are not birds, > A listening room is not nature." > Klas Strandberg > Yahoo! Groups Links > > > > > > __________________________________ Do you Yahoo!? Yahoo! Mail Address AutoComplete - You start. We finish. http://promotions.yahoo.com/new_mail ________________________________________________________________________ ________________________________________________________________________ ```
 Current Thread Re: Edmund Parabolic Reflectors, (continued) Re: Edmund Parabolic Reflectors, Dave J Re: Edmund Parabolic Reflectors, Gregory Kunkel Re: Edmund Parabolic Reflectors, Walter Knapp Re: Edmund Parabolic Reflectors, Walter Knapp Re: Edmund Parabolic Reflectors, Mike Feldman Re: Edmund Parabolic Reflectors, Eric Benjamin Re: Edmund Parabolic Reflectors, Gregory Kunkel Re: Edmund Parabolic Reflectors, Mike Feldman Re: Edmund Parabolic Reflectors, Jim Morgan Re: Edmund Parabolic Reflectors, Dave J Re: Edmund Parabolic Reflectors, Gregory Kunkel <= Re: Edmund Parabolic Reflectors, Gregory Kunkel Re: Edmund Parabolic Reflectors, Rich Peet Re: Edmund Parabolic Reflectors, Mike Feldman Re: Edmund Parabolic Reflectors, Jim Morgan RE: Edmund Parabolic Reflectors, Martyn Stewart Re: Edmund Parabolic Reflectors, Dave J Re: Edmund Parabolic Reflectors, Klas Strandberg Re: Edmund Parabolic Reflectors, Klas Strandberg Re: Edmund Parabolic Reflectors, Jim Morgan Re: Edmund Parabolic Reflectors, Klas Strandberg