Wednesday, November 29, 2006

How to Build a Remote Caller

Here is a plan of how to build your own remote controlled varmint caller.

The 'designer' of this setup is Mr. Lourens Goosen of the Free State Nature Conservation. He does not hold any ‘patent rights’ on this and explicitly gave me permission to publish this info. Any further information needed can be asked by emailing a request from my web page at

The photos can be seen below this text.

The basic player is a normal automobile Radio/CD player of the type with an infrared remote controller. The remote uses an infrared light beam to control the CD player, volume, ON/OFF and track select. The range of such infrared controllers is measured in feet rather than yards. The range is enough to reach from where you may be hidden in the shade of a tree [or sitting on the back of a pickup truck] to where the transmitter is up on a branch in the tree [on the roof of the pickup]. The trick is that he uses what he calls “blaster” transmitter/receivers that converts the infrared light into a radio signal. These ‘blasters’ are readily available from many radio/TV shops in South Africa, and I would assume also in the USA?

He would control the setup by the remote that activates the blaster pick-up through the transparent plastic. The receiver ‘blaster’ then converts the radio signal back into infrared, which in turn controls the CD player. By using vertically installed aerials he claims that he gets at least 100 yards line of sight control. The higher the transmitter is the further the likely range at which the radio signal can be picked up by the remote caller. He told me that the maximum he has achieved is 270 yards on a downhill line of sight setup. Lourens says that the big plus of this setup is that there is no radio-type “hiss” on the speakers, as the radio signal only controls the car remote control. The sound quality is as good as your CD and the CD player & speaker! Naturally the remote is simple, no keypad and just a single step forward to next track. You have to make a memory note of which sound is on which track.

I most surely intend building one for my own use. The big cost here is the car radio/CD player, which cost about R 1000 in South Africa.

The first photo show the actual caller in the wooden camo box and the transmitter in clear plastic container on top of it. This one has a 10 W horn speaker mounted on the outside. What can not be seen is the 12 volt battery behind the Radio/CD player.

Here a close-up of the actual automobile Radio/CD player. With the sliding rear panel removed. Here is a Sony, but any brand will do! The reciever 'blaster' is mounted above the radio/CD player. The infrared light reflects off the removed back lid well enough to be picked up by the reciever on the radio/CD player. Watch out for a metal box - it will absorb the 'heat' much better than wood, which reflects the infrared 'heat'!

The clear plastic container with the actual infrared car Radio infrared remote wrapped in clingwrap foil to protect it from rain etc. on top of container.

Just another close up view of system.

The transmitter with lid removed.

The 12 volt batteries last for at least a few nights' actual calling. Remember to recharge these batteries at a slow charge rate. A so called 'trickle charger' will do the job quite well. A normal automobile battery cahegre will likely cause damage - it is said even an exploded? - battery.
This is the biggest, by far, lynx or caracal I've ever seen!

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