Xref: utzoo sci.electronics:5968 rec.ham-radio:10366
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!oakhill!val!ben
From: ben@val.UUCP (Ben Thornton)
Newsgroups: sci.electronics,rec.ham-radio
Subject: Re: ultrasonic mics/transducers
Keywords: ultrasonic microphones
Message-ID: <328@val.UUCP>
Date: 25 Apr 89 15:40:13 GMT
References: <1989@otis.oakhill.UUCP>
Reply-To: ben@val.UUCP (Ben Thornton)
Organization: Video Associates Labs - Austin, TX
Lines: 28


In article <1989@otis.oakhill.UUCP> charlie@oakhill.UUCP (Charlie Thompson) writes:
>I am looking for something to use as an ultrsonic microphone.
>I have a little 25KHz ultrsonic transducer but it is resonant
>at 25KHz and offers a very narrow bandwidth around 25.  I'd like
>to have something with a broader response.  I tested a cheapie
>condenser mic and it seems to work at 25K pretty well.  The
>intended application is a tuneable untrasonic receiver of the
>heterodyne/homodyne variety and hence the need for broad-bandedness.
>Coverage up to 40KHz is desireable.

  Hmmm... how about one of those cheap electret pellet microphones?
These are the kind that are built into small cassette tape recorders
and hand-picked ones are used as the element in a PZM.  They are
normally bandwidth-limited by the circuit they are used in, but I
think they will actually respond well into the ultrasonic range.
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-- 

Ben Thornton             packet:  WD5HLS @ KB5PM
Video Associates Labs      uucp:  ...!cs.utexas.edu!oakhill!val!ben
Austin, TX              fidonet:  1:382/40 - The Antenna Farm BBS