Stephanie Maks - VA3GRR Radio Beacon

On Air

Introduction

VA3GRR is a radio beacon, operating on the 10 meter amateur band. Its frequency is 28.205.5 MHz. It runs just under 5 watts of power into a vertical half-wave ringo style antenna. It transmits a message in CW (Morse Code) which plays over and over again. The message that is transmitted contains the call-sign, the beacon's location and Maindenhead Grid position, and then a random word which is changed irregularily.

I run VA3GRR 'around the clock'; it runs pretty much unattended. The rig is located in my studio where I can see its indicator LEDs, so I know at a glance that it's running and all is well.

VA3GRR has been running, in one form or another, since the late 1990's. It's been through a number of overhauls and rebuilds, both the transmitter and the controller have been built over again quite a few times. I got the beacon idea from my friend Hugh (VA3TO), who operates a beacon on the 6 meter band. Hugh also got me started with some code for the microcontroller PIC16F84A.

This beacon is an Amateur Radio project. For information on Amateur Radio, click here.

Operation

My beacon is now just a wee little controller board that is plugged into the home-made data port on my Elecraft K2 transciever.

On the Controller board, there are 5 small 'DIP' switches. Left to right these are: Run program; Message 1; Message 2; Message 3; and Message 4. The first Green LED indicates Power, the second Green LED indicates Status. The first Red LED is a Fault indicator and the second Red LED is the Transmit LED. The two Yellow LEDs are not used at the moment.

To activate the beacon, all I have to do is turn on the K2, and make sure that it's set to the right frequency, mode, and power level. Then I lock the K2 controls, and on the beacon controller, I set the first DIP switch, and then pick one of five messages with the other four DIP switches (if the other four switches are all 'off', then Message 0 is played).

Controller

The Controller is built around a Microchip Technology PIC16F84 microcontroller. This PIC chip has 13 I/O ports and uses a very simple crystal oscillator. It can run a beacon very easily. I've configured it with 5 inputs and 8 outputs; the 5 inputs allow the selection of different stored messages, and also allow it to monitor a 'Fault' signal. The 8 outputs let it control status LEDs as well as the keying circuit. For information on the beacon program, see below.

The Controller has two connectors. J1 has 3 connections: #1 is Power In (+5 volts DC); #2 is Ground; #3 is the Keying signal. These three lines connect with J2 on the Transmitter board. J2 has 4 connections: #1 is the Fault input; #2, 3 & 4 are extra outputs. The Controller is designed so that it can be used as a stand-alone beacon controller, so it can be connected to any transmitter that grounds the key line for transmitting. It would also be a very simple programming change to configure one of the 3 extra outputs for positive keying, if required. A schematic of the controller can be viewed by clicking the thumbnail below.

Programming

The PIC program is pretty straightforward. When started, the program first cycles through a LED test to ensure all the outputs are working correctly. Then it starts running the loop which contains the actual beacon message. Towards the end of the fixed message, it tests the four DIP switches and if any are on, it selects one of the alternate message words. Otherwise it sends the default message word. It then loops back to the beginning. A number of subroutines also exist, including one for each CW character (letters, numbers, some prosigns), the delay base, and a fault detection and handling routine.

If you like, you can download or view the beacon software by clicking the thumbnail below.

Reports

In the half-dozen or so years that I've had my beacon running, I've received reports from all over North America, parts of South America, and from the UK and parts of Europe. For information on other 10 meter beacons, a list is maintained by Bill WJ5O of Corpus Christi, Texas.