I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went farther
than building simple demonstration circuits. I wondered if there was anyone
on this list that may be able to shed some light on what I would need and/or
how I would use them (a schematical description), or even point me to the
"yellow brick road".


Thanks!
--
//Clint Alexander

Clint Alexander wrote:
I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

Try burying a WiFi dongle and see what you get. 2.4gHz has the advantages
of being COTS (commercial off the shelf technology), easy to build
directional antennas, cheap and easily adapated to digital technology.

It also has the advantage of being legal in almost (if not) every country
in the world.

I'm not sure it will reach through 3-10 feet of dirt, but I expect that
anything much above 15khz will have that problem.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

On Jun 1, 4:44*pm, "Geoffrey S. Mendelson"
wrote:
Clint Alexander wrote:
I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

Try burying a WiFi dongle and see what you get. 2.4gHz has the advantages
of being COTS (commercial off the shelf technology), easy to build
directional antennas, cheap and easily adapated to digital technology.

It also has the advantage of being legal in almost (if not) every country
in the world.

I'm not sure it will reach through 3-10 feet of dirt, but I expect that
anything much above 15khz will have that problem.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel *N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.

On Jun 1, 5:22*pm, UKMonitor wrote:
On Jun 1, 4:44*pm, "Geoffrey S. Mendelson"
wrote:





Clint Alexander wrote:
I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

Try burying a WiFi dongle and see what you get. 2.4gHz has the advantages
of being COTS (commercial off the shelf technology), easy to build
directional antennas, cheap and easily adapated to digital technology.

It also has the advantage of being legal in almost (if not) every country
in the world.

I'm not sure it will reach through 3-10 feet of dirt, but I expect that
anything much above 15khz will have that problem.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel *N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

Try googling Avalanche / beacon / tranceiver / 457KHz

http://pistehors.com/backcountry/wik...e-Transceivers

UKM- Hide quoted text -

- Show quoted text -

Also Loc8tor

http://www.loc8tor.co.uk/Store/

UKM

UKMonitor wrote:
http://www.loc8tor.co.uk/Store/

I don't know what you are hiding, but some of the ELT (Emergency locator
transmitters) are tracked by satellite, and if you set one off sirens
go off in control centers.

Great if you are trying to get rescued, a disaster if you want to find
your "stash".

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

On Jun 1, 10:21 am, "Clint Alexander" wrote:
I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went farther
than building simple demonstration circuits. I wondered if there was anyone
on this list that may be able to shed some light on what I would need and/or
how I would use them (a schematical description), or even point me to the
"yellow brick road".

Thanks!
--
//Clint Alexander

Andy writes: I messed with a transmitter used to map out caves and
tunnels a while back and think that would fit your bill. I don't
remember the details
but I think it ran around 100 Khz or so, and the antenna was just a
coil
of wire about a foot in diameter, using magnetic near field coupling.
Power was only a few watts and the range was hundreds of feet.

If you google things like "cave mapping" , " spelunking
transmitters",
and keywords like that, you may have a lead to follow.

Good luck,

Andy W4OAH

On Jun 2, 12:35*am, AndyS wrote:
On Jun 1, 10:21 am, "Clint Alexander" wrote:





I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would be
a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went farther
than building simple demonstration circuits. I wondered if there was anyone
on this list that may be able to shed some light on what I would need and/or
how I would use them (a schematical description), or even point me to the
"yellow brick road".

Thanks!
--
//Clint Alexander
Andy writes: * *I messed with a transmitter used to map out caves and

tunnels a while back and think that would fit your bill. *I don't
remember the details
but I think it ran around 100 Khz or so, and the antenna was just a
coil
of wire about a foot in diameter, using magnetic near field coupling.
Power was only a few watts and the range was hundreds of feet.

* *If you google things like "cave mapping" *, " spelunking
transmitters",
and keywords like that, you may have a lead to follow.

* * * * * * Good luck,

* * * * * * *Andy W4OAH- Hide quoted text -

- Show quoted text -

At 457KHz they use ferrite rod antennas

I think if you are building your own system you need a crystal locked
transmitter and a very narrow bandwidth ( DSP filters ? ) receiver in
order to obtain the best range and rejection of unwanted noise and out
of band signals.

Some design notes can be found here.

http://www.ece.uvic.ca/~mblarows/ELE...ort%202-r1.pdf

http://www.backcountryaccess.com/eng...Future_000.pdf

Google or search US patent websites for 457KHZ transmitter antenna.

UKM

UKM

For all involved in the thread -- here's a perfect example. Sondes are
locator systems used in many areas (I think) such as pipelines:
http://www.rjmcompany.com/Pipe-cable...0-SuperCAT.htm

These have frequencies of 512hz, 8Khz and 33Khz

I'm searching for any specs now regarding crystal and antenna for both
transmitter and receiver. But I'm certain that the antenna isn't 1000's of
meters long

If I'm reading this right -- I would want to build my own version of the
technology rather than purchase theirs'.

--


//Clint Alexander

"Clint Alexander" wrote in message
news
I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would
be a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went farther
than building simple demonstration circuits. I wondered if there was
anyone on this list that may be able to shed some light on what I would
need and/or how I would use them (a schematical description), or even
point me to the "yellow brick road".


Thanks!
--
//Clint Alexander

On Jun 3, 12:53*am, "Clint Alexander" wrote:
For all involved in the thread -- here's a perfect example. Sondes are
locator systems used in many areas (I think) such as pipelines:http://www..rjmcompany.com/Pipe-cabl...0-SuperCAT.htm

These have frequencies of 512hz, 8Khz and 33Khz

I'm searching for any specs now regarding crystal and antenna for both
transmitter and receiver. But I'm certain that the antenna isn't 1000's of
meters long

If I'm reading this right -- I would want to build my own version of the
technology rather than purchase theirs'.

--

//Clint Alexander

"Clint Alexander" wrote in message

news


I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would
be a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went farther
than building simple demonstration circuits. I wondered if there was
anyone on this list that may be able to shed some light on what I would
need and/or how I would use them (a schematical description), or even
point me to the "yellow brick road".

Thanks!
--
//Clint Alexander- Hide quoted text -

- Show quoted text -

I think we need to know a bit more about your application.

I have one of these pipe / cable locators, you need to have a good
idea of the route the pipework its taking and then 'sweep' the
approximate area with the end of the locator. If you don't have a
starting point it's very time consuming to cover a large area.

The avalanche beacon permits initial detection over a much wider area
which considerably speeds up a 'blind' search.

What size transmitter (physical) are you able to use, Max weight,
Battery duration, required detection radius, depth of burial etc.

UKM

The relationship is so close, I would suggest that the Sonde is a perfect
application for my needs.

Like I said previously, I want to build my own version. So we'll assume this
as the target technology leaving me with the question of what antenna would
be needed to perform these operations. I suppose the oscillator is just a
simple crystal or perhaps even voltage controlled (adjustable). I can use a
555 for this....



--


//Clint Alexander

"UKMonitor" wrote in message
...
On Jun 3, 12:53 am, "Clint Alexander" wrote:
For all involved in the thread -- here's a perfect example. Sondes are
locator systems used in many areas (I think) such as
pipelines:http://www.rjmcompany.com/Pipe-cable...0-SuperCAT.htm

These have frequencies of 512hz, 8Khz and 33Khz

I'm searching for any specs now regarding crystal and antenna for both
transmitter and receiver. But I'm certain that the antenna isn't 1000's of
meters long

If I'm reading this right -- I would want to build my own version of the
technology rather than purchase theirs'.

--

//Clint Alexander

"Clint Alexander" wrote in message

news


I want to make a simple transmitter to use as a locator beacon. But the
source would be in the ground (anywhere between 3 - 10ft). The receiver
would need to locate it, much like a metal detector would except it would
be a small hand-held "wand" with a LCD giving the direction and signal
strength.

I'm not sure of the signaling to use therefore I'm not sure of the
antenna
required. But, it would need it to follow part 15 of the FCC
rules/regulations (none hazardous and allows required interference).

I am completely new at this sort of technology. I have created circuits
before using L555 timer, 4046Phase Loop, etc. But I've never went
farther
than building simple demonstration circuits. I wondered if there was
anyone on this list that may be able to shed some light on what I would
need and/or how I would use them (a schematical description), or even
point me to the "yellow brick road".

Thanks!
--
//Clint Alexander- Hide quoted text -

- Show quoted text -

I think we need to know a bit more about your application.

I have one of these pipe / cable locators, you need to have a good
idea of the route the pipework its taking and then 'sweep' the
approximate area with the end of the locator. If you don't have a
starting point it's very time consuming to cover a large area.

The avalanche beacon permits initial detection over a much wider area
which considerably speeds up a 'blind' search.

What size transmitter (physical) are you able to use, Max weight,
Battery duration, required detection radius, depth of burial etc.

UKM