Devices for listening through walls

[stan]

Can anyone point me to any webisite or provide me information about
how to build a device that can listen through a concrete wall?

Thanks

 

[burbeck]

On 25 May 2004 23:38:52 -0700, stanfleisch90@hotmail.com (stan) wrote:

Can anyone point me to any webisite or provide me information about
how to build a device that can listen through a concrete wall?

Thanks

hi there stan,
the tradishional method for a device of this type is an inverted wine
glass,

 

[burbeck]

On Wed, 26 May 2004 09:31:18 +0100, burbeck <crooksie@bigfoot.com>
wrote:

On 25 May 2004 23:38:52 -0700, stanfleisch90@hotmail.com (stan) wrote:

Can anyone point me to any webisite or provide me information about
how to build a device that can listen through a concrete wall?

Thanks

hi there stan,
the tradishional method for a device of this type is an inverted wine
glass,

traditional even

 

stanfleisch90@hotmail.com (stan) wrote:

Can anyone point me to any webisite or provide me information about
how to build a device that can listen through a concrete wall?

I'd start with a small masonry bit, sized for my microphone element...

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[Johnboy]

I built one of those gadgets back in my high school days
for science class. I glued several types of microphones
into holes drilled in suction cups of all types. Then built
a high gain amp and used headphones. I recall we used
plumbers putty around the edge of the cup for use on
locker room cinder block walls, all that was needed was an
air tight seal. The thing worked real good and was a lot of fun.
Not much high tech needed for this application.

Can anyone point me to any webisite or provide me information
about how to build a device that can listen through a concrete wall?

Thanks

 

[Watson A.Name - \"Watt Su]

<William P.N. Smith> wrote in message
news:uhs8b0tjgk08t3uitnhm7lmgd660921qsv@4ax.com...

stanfleisch90@hotmail.com (stan) wrote:
Can anyone point me to any webisite or provide me information about
how to build a device that can listen through a concrete wall?

I'd start with a small masonry bit, sized for my microphone element...

Speaking of walls.. I wonder what happened to the guy who wanted to use
a dog repeller on some neighbor's mutts that were several hundred feet
away..

I was talking to a lady the other day and she said that they had bought
a dog repeller to use on their neighbor's dog. They're right next door,
and they put it on the side of their house. But she said that it had a
very limited range, so even tho the device worked on the side of the
house, the dog would just go into the back yard and keep on barking.
THis unit has a bark sensing circuit, and an ultrasonic element to
produce high levels of sound near the unit. But I guess ultrasound
doesn't travel as far as regular sound as it gets absorbed and
dissipates faster. So her unit isn't effective enough to cover the
whole area. She saisd that it cost something like $70 from some company
online.

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com