Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...

Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term


Richard H. Kuschel
"I canna change the law of physics."-----Scotty

Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term


Richard H. Kuschel
"I canna change the law of physics."-----Scotty

Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Yup that's the critter I want to build

"Dale Farmer" wrote in message
...


Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Yup that's the critter I want to build

"Dale Farmer" wrote in message
...


Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

DN wrote:

Yup that's the critter I want to build

Then the main design problem is instead of picking up
vibrations from air you want to pick up vibrations from the
nail or pin, and not the surrounding air. Some sort of insulating
can around the backside, and attach the pins to the actual
sensing element.
There is the problem that the pin/nail will need to stand up to
a lot of pressure when it is pushed into the medium you are
listening through. this would be an interesting challenge to design,
if I knew how to design microphones.

--Dale

DN wrote:

Yup that's the critter I want to build

Then the main design problem is instead of picking up
vibrations from air you want to pick up vibrations from the
nail or pin, and not the surrounding air. Some sort of insulating
can around the backside, and attach the pins to the actual
sensing element.
There is the problem that the pin/nail will need to stand up to
a lot of pressure when it is pushed into the medium you are
listening through. this would be an interesting challenge to design,
if I knew how to design microphones.

--Dale

This shouldn't be too hard to do. I remember when I was back in high school
(*sigh*) I built a "wireless microphone" which of course was actually just a
listening bug. When I put it on a table and someone set a coffee mug down on
it, I'd get a loud "boom" from the receiver speaker. The sound waves coupled
through the table were much stronger than the ones arriving through the air.
This wireless device used one of those little electret mics. I think it
would be easy to reduce the sensitivity of the circuit, add a voice
pass-band filter, and then figure a simple way to add a wall mounting
system. Perhaps a pin if you don't want to do much cosmetic damage to the
wall. Either way it doesn't take much pressure to couple the device to the
mounting surface.
Email me if you'd like more detail and a schematic.




"DN" wrote in message
ink.net...
Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...

This shouldn't be too hard to do. I remember when I was back in high school
(*sigh*) I built a "wireless microphone" which of course was actually just a
listening bug. When I put it on a table and someone set a coffee mug down on
it, I'd get a loud "boom" from the receiver speaker. The sound waves coupled
through the table were much stronger than the ones arriving through the air.
This wireless device used one of those little electret mics. I think it
would be easy to reduce the sensitivity of the circuit, add a voice
pass-band filter, and then figure a simple way to add a wall mounting
system. Perhaps a pin if you don't want to do much cosmetic damage to the
wall. Either way it doesn't take much pressure to couple the device to the
mounting surface.
Email me if you'd like more detail and a schematic.




"DN" wrote in message
ink.net...
Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...

On Fri, 31 Oct 2003 02:15:20 GMT, Dale Farmer
wrote:



Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Spike mikes are actual mettalic spikes that can be pushed in to a
wall.
They have a transducer pickup on the end that will pick up the minute
vibrations and once greatly amplified can be heard/recorded.
You can usually pick them up in spy shops.
They've been around since the late 40's.
On another note the spike can be made of wood. The Russians taught us
that back in the 50's when they bugged the entire American embassy in
Berlin. Couldn't be detected with the metal detectors of the day and
tons of secret conversations were had by the Soviets.

On Fri, 31 Oct 2003 02:15:20 GMT, Dale Farmer
wrote:



Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Spike mikes are actual mettalic spikes that can be pushed in to a
wall.
They have a transducer pickup on the end that will pick up the minute
vibrations and once greatly amplified can be heard/recorded.
You can usually pick them up in spy shops.
They've been around since the late 40's.
On another note the spike can be made of wood. The Russians taught us
that back in the 50's when they bugged the entire American embassy in
Berlin. Couldn't be detected with the metal detectors of the day and
tons of secret conversations were had by the Soviets.

On Fri, 31 Oct 2003 02:15:20 GMT, Dale Farmer
wrote:



Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Spike mikes are actual mettalic spikes that can be pushed in to a
wall.
They have a transducer pickup on the end that will pick up the minute
vibrations and once greatly amplified can be heard/recorded.
You can usually pick them up in spy shops.
They've been around since the late 40's.
On another note the spike can be made of wood. The Russians taught us
that back in the 50's when they bugged the entire American embassy in
Berlin. Couldn't be detected with the metal detectors of the day and
tons of secret conversations were had by the Soviets.

On Fri, 31 Oct 2003 02:15:20 GMT, Dale Farmer
wrote:



Richard Kuschel wrote:


Ok Audio Mavens,

I need to construct or buy spike mike or similar device.

Anyone?

Thanks...



What is a Spike mic? Not familiar with the term

The only Spike Mic I can think of might be the specialized
surveillance
microphones used by SWAT units in hostage type situations. They are
a microphone mounted to a nail and the thing is pushed into the opposite

side of the wall of the room you wish to listen too. The spike picks up

the vibrations of the wall induced by the sounds in the next room. ( and
the
sounds in this room, and the gurgles of the plumbing, and trucks driving

down the highway half a mile away, and, and and... )
Such toys are sold in specialty law enforcement catalog companies,
and
are generally not available to the public.

--Dale

Spike mikes are actual mettalic spikes that can be pushed in to a
wall.
They have a transducer pickup on the end that will pick up the minute
vibrations and once greatly amplified can be heard/recorded.
You can usually pick them up in spy shops.
They've been around since the late 40's.
On another note the spike can be made of wood. The Russians taught us
that back in the 50's when they bugged the entire American embassy in
Berlin. Couldn't be detected with the metal detectors of the day and
tons of secret conversations were had by the Soviets.