June 1st 10, 05:32 PM
posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Aug 2009
Posts: 13
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What to use for an underground transponder?
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
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