Outline

The idea is for someone to hide the transmitter and then others to find it using a receiver and various antennas and techniques to determine the direction to follow.

Transmitter

The transmitter is the same as the RC lost model transmitter but with a easier to follow beep transmission and a shorter antenna. The shorter antenna reduces the transmitted signal making it easier to track in a smaller area like a local park.

Activate the transmitter by removing the small black jumper and put the transmitter in a plastic bottle to protect it and hide it somewhere not too obvious. Don’t loose the jumper as it’s needed to turn the transmitter off later. If you’re hunting in a smaller area the transmitter can be on the ground but for a larger area if you hang it in a tree signal coverage will be better. Try to keep the antenna wire straight and vertical.

Receiver

The receiver contains a 9V alkaline battery that should last quite some time. The small white button on the bottom end turns the receiver on and off as well as toggling the squelch on and off.

Power On/Off

Push and hold the button for about 4 seconds to turn the receiver on. It will hiss when and stay on. A shorter press will not latch it on; to prevent accidentally draining the battery. When it is on you can turn it off by pressing and holding the button for 5 seconds while the LED flashes. When the LED stays on, release the button and the receiver turns off. The receiver will automatically turn off 15 minutes after the button was last pressed.

Squelch – power button

Press the power button to toggle the squelch off to on or on to off. When the squelch is off or “open” you can hear the hissing noise and occasional other signals on the same frequency.

When the received signal is strong the squelch will allow just the required signal to be heard and mute the hissing. Most of the time you will need to hear all the noises to work out what’s going on.

Two attenuator toggle switches

The attenuator reduces the signal from the antenna that passes to the receiver. This can be useful when tracking a stronger signal; getting closer.

Two switches allow 4 attenuator settings from no attenuation to maximum attenuation with both switches on.

Headphones can be plugged in and can make it easier to hear weak signals and determine direction more accurately.

Antennas

There are many antenna options from simple omnidirectional whips to higher gain directional types like the yagi. The transmitter operates at 433.92 MHz which is high enough that antennas can be quite good but not too large.

To determine direction more accurately from a distance a yagi is a good idea. For smaller areas and close in hunting a whip or no antenna is required.

Hunting

Starting some distance out use the yagi antenna to detect the signal. Slowly sweeping the antenna and trying horizontal and vertical (polarisation) you are looking for the strongest or clearest signal.

When the yagi angle (horizontal/vertical) is matching the transmitter antenna you will have the best signal. Rotating the yagi off axis is a good way to reduce the signal level as you get closer to the transmitter.

At some point the signal will be too strong for the yagi and you won’t be able to choose a direction. At this point try the receiver without a antenna at all. If you can hear the signal, try using your body as a shield by holding the transmitter close in front of your chest and slowly rotate. You will find that when the signal is best the transmitter is in front of you or when the signal disappears the transmitter is behind you. Repeating this process at various locations you can home in on the transmitter.