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Melor Antenna Position Encoder
by Jim Smerdel

This is the MELOR antenna position encoder and signal strength unit. It is accurate to 1 degree and includes a LCD bar graph turn indicator to keep the antenna wire from getting wound up. It uses the US Digital shaft encoder to track the antenna position. The heart of the electronic unit is a PIC16F877. The unit gives positions to the 'T' relative to the front of our truck.

We then enter this number into a program on our laptop which reads the current heading of the truck from our GPS and draws a vector on Street Atlas from our current position to the 'T'.

The next generation MELOR unit will include a bar graph signal strength meter and a top secret (Paul-Vector Finder) function, guaranteed (by Paul) to never fail.

One additional feature we're contemplating is a fail safe button. When you realize that you are totally lost and there is no hope of finding the 'T', you would push this button and the LCD would suggest reason why you have to quit the hunt early. For example:

  • Our alternator has failed and our battery is getting low... see yah at the next hunt.
  • My wife called and the baby is sick, I need to get home right away.
  • We know where the 'T' is, but we're low on gas and must get to a gas station.

Melor Antenna Position Encoder

This is a photo of the MAPE on the test bench.

The Liquid Crystal Display panel on the left indicates the bearing the antenna points relative to the hunt vehicle. Here a message also appears to remind the user not to turn the antenna too many times in one direction and wind up the antenna cable. The left display is an analog signal strength meter. Like the LCD, it is illuminated for night use.

Melor Antenna Position Encoder - Revealed

Open on the test bench from above.

Like so many electronic devices, there often isn't a lot in the box. A single board device containing a PIC16F877 microcontroller with custom program is the heart of the device. It communicates with the signal level output of a modified radio receiver and the position indicating electronics mounted at the base of the antenna mast.

Melor Antenna Position Encoder - Angle Sensor

A view from the side of the MAPE angle sensor mounted in the hunt vehicle.

The antenna mast seats in the white PVC connector above the board, and a shaft through the wood turns the turn counter mounted underneath. To the right is a jack for convenient connection to the main unit.

Melor Antenna Position Encoder - Antenna Mast Step

A view from the top of the MAPE antenna mast step in the hunt vehicle.

The antenna mast rests here and is connected to the turn counter which is mounted under the wood support.


Credit to Jim Smerdel for concept, engineering and production of both hardware and firmware associated with the Melor Antenna Position Encoder.


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