Hello!
Years ago, I sometimes played the transmitter hunting game, probably known to
most of the members of this list.
A friend of mine recently suffered a theft so I thought about the opportunity
to embed little marker transmitters in some object usually left in the yard
(like bicycles for
Hello Andrea,
The angle could be found with a directional antenna or inerferometry, but about
the distance?
About the only reliable way to locate hidden transmitters is by field
strength. The problem in built-up areas is reflections.
At one time Doppler DF systems were popular, but anybody
Hi Andrea:
There are a number of object location schemes. I got interested after seeing the blue dot in the movie The Da Vinci
Code.
It is a totally fictional device.
A lot of new products like a blue dot are coming on the market based on
Bluetooth and the use of smart phones.
But there are
You don't need much power because the device in the toy only needs to
transmit for a few milliseconds then shut off. Some transmuter you
have pings the device in the toy that acts like a transponder. It
only transmits in response to a ping. So limey it can be powered
by a button battery.
Hi Chris:
The trouble with a transponder is the receiver is a power hog.
One way to mitigate that is to have the receiver operate on a low duty cycle and use a transmit signal that's longer
than the receive period.
The military PRC-68 squad radio used this method and the squelch opened so fast
I should mention that the circuit that I attached in the previous post does not
output at 49.152 MHz The output is the third (or fifth?) harmonic of the
crystal frequency...
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At 06:40 AM 5/27/2014, Graeme Zimmer wrote:
A simple beam or dipole is useful, but only when out in the open country
I have seen some of the equipment used by FCC field agents when DFing
deliberate interference to aircraft communications. They used three
transportable fixed mountaintop
On Tuesday, May 27, 2014, Mark Sims hol...@hotmail.com wrote:
I should mention that the circuit that I attached in the previous post
does not output at 49.152 MHz The output is the third (or fifth?)
harmonic of the crystal frequency...
I have had very good luck with these 433 MHz TX
I built some RF beacons for my friend's high power (TRIPOLI) rocketry
projects. We use a TELEVILT UHF wildlife tracking receiver from Sweden
(pricey) that operates in the 434 MHz ISM band. The transmitters are
LINX TXM-LR series transmitter chips with an 8 pin PICAXE processor. The
modulation
On Tue, May 27, 2014 at 11:32 AM, Brooke Clarke bro...@pacific.net wrote:
Hi Chris:
The trouble with a transponder is the receiver is a power hog.
Why does a receiver have to be a power hog? I remember building a
receiver once that did not use any power other then the energy coming
in from
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