HF Tracker - SARCNET

School Amateur Radio Club Network
School Amateur Radio Club Network
School Amateur Radio Club Network
School Amateur Radio Club Network
Go to content
Universal HF Tracker with F4GOH
We will be using this Universal HF Tracker PCB, based on our original Arduino Pro Micro tracker design and expertly produced by Anthony F4GOH, to build a variety of different SARC projects. The PCB can produce a High Frequency RF signal in the range of 1MHz to 12.5MHz using an AD9833 Direct Digital Sequence (DDS) frequency synthesizer. The signal can be modulated with different Weak Signal modes such as WSPR, JT9 and JT65 using our Arduino 5V/16MHz Pro Micro software. The PCB also connects the Arduino to an external GPS receiver, I2C bus, analog and digital I/O. It could therefore broadcast the position of the tracker as well as other telemetry information for thousands of kilometres over the air.

Please visit Anthony Le Cren's excellent Ham Projects blog. Contact Anthony if you wish to buy PCBs.
This is the top side of Anthony's PCB.
It measures approximately 50mm (2") square and weighs only 4g.
J1 is the battery input.
J2 offers 5V and GND plus 3 Digital I/O or ADC inputs.
J3 is for an AD9833 DDS.
J4 is for an I2C bus.
J5 is for the GPS.
J6 is for the SMA antenna connector.
J7 enables the RF output.
J8 is for an external reset switch or to extend the power on reset function.
U1 is a voltage regulator.
U2 is an Arduino Pro Micro.
U3 is a DS18S20 OneWire temperature sensor
This is the bottom side of Anthony's PCB, which is used for the surface-mounted capacitors.
The board is packed with many important features:
A resistor divider network, R13/R14, enables the Arduino to monitor the battery voltage.
The P-Channel MOSFETS, Q3/Q4, are used to enable and disable the DDS and GPS subsystems for power savings.
The RF Amplifier uses two BS170 FETs in parallel for higher output power.
The FETs are powered directly from the 6V battery supply.
The Low Pass Fileter L1, L2, L3 and C5, C6, C7 and C8 reduces the harmonics generated from the DDS.
On onboard voltage regulator provides 5V to the Arduino, DDS, GPS and the temperature sensor.
Project 1: WSPR Beacon
This project will be a Weak Signal Propagation Reporting beacon. When signals from this beacon are received by a network of listening stations, it will help us and Amateur Radio operators all around the world understand the prevailing ionospheric propagation conditions. Checkout here what that looks like.
Project 2: High Altitude Balloon Payload
This project will help us track our High Altitude Balloons which can, if the conditions are right, circumnavigate the globe in the jetstreams of the upper athmosphere. Please note that under section 115 of the Australian Environment Protection Act 2017, it is now illegal to launch balloons into the environment, even for scientific and educational reasons, without approval.
Project 3: Ocean Current Tracker
This project will help us track our free-floating ocean buoys. The buoys will follow the worlds ocean currents. We can learn about the flow of ocean currents. Who knows where they will end up?
Back to content