[TowerTalk] Another Antenna Azimuth Indicator

[David Gilbert]

A few weeks ago I described a system to remotely monitor the direction 
my antennas were pointing after the potentiometer in my Prosistel 
PST-71D crapped out.  It used 18 discrete Hall Effect switches, and 
while it works fine it does seem like a bit of a clumsy approach even to 
me and the resolution isn't ideal.

Csaba, HA3LN, saw my video and mentioned that he was working on a 
similar project but using a rotary Hall Effect angle sensor.  I liked 
his idea a lot, but he plans to mechanically connect the sensor to the 
rotator and I prefer to have a non-mechanically connected setup using 
magnetic coupling.  A video describing my latest approach can be found here:

https://youtu.be/2XbAxJ5nDBI

It's a simple and relatively inexpensive way to remotely monitor which 
direction an antenna is pointed without needing a mechanical connection 
to the mast holding the antenna. The resolution is pretty good, 
certainly better than the beam width of almost any amateur radio 
antenna. It uses a rotary Hall Effect angle sensor together with an 
Arduino to convert the output of the sensor to degrees and display the 
azimuth on a small OLED display. Magnetically linked wheels ("gears") 
... one on the mast and another mounted nearby ... couple the mast 
rotation to the rotary sensor. The software for the Arduino is extremely 
simple, can be programmed from almost any computer via a USB connection, 
and is available upon request. The items that were 3D printed were 
created using OpenSCAD, but should probably be reworked for smaller 
magnets and a smaller overall size.

Many thanks to Csaba, HA3LN for the suggestion to use the rotary Hall 
Effect angle sensor, and to my son Scott for the code for the very 
effective adaptive jitter filter.

As usual, any thoughts for improvement are appreciated.

73,
Dave AB7E