This 80 metre fox-or transmitter is a very small low power transmitter which mounts inside a plastic conduit. Its primary use is small foxhunts and fox-or-ing (orienteering style) foxhunt events.

The PCB measures just 40x12mm and runs off a pair of AA batteries. The transmitter operates on the fixed frequency of 3.58MHz and has an output of approximately 6dBm (4mW).

A short antenna about 40cm long gives the transmitter a range of about 100 metres. A longer antenna will give greater range.

For a number of reasons however this product has now been discontinued.  Plans for building the transmitter are shown below. Design source files can also be provided if required.

1) Schematic

2) PCB Overlay

3) PCB Bottom Layer

4) PCB Bottom component assembly

5) Case mechanical details

For fox-or-ing use in a typical course would use between 5 and 10 transmitters.

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