HX1 – VHF Narrow Band FM APRS Transmitter (144.39Mhz – NA)
The HX1 is a low-power amateur radio transmitter set to a fixed frequency of 144.390 MHz. In North America, this frequency is used for the Automatic Packet Reporting System, or APRS.
APRS is a standard used by amateur-radio operators to broadcast live sensor data on a shared frequency. This data can be received by anyone with the proper equipment, and is aggregated on the internet through gateways run by members of the APRS community. APRS is commonly used to share real-time data including vehicle location (GPS), weather stations, high-altitude balloon tracking, remote sensor platforms, disaster relief coordination, and more. It’s effectively an open-source, open-data, community-run, free to use, IoT system with potentially worldwide coverage.
The HX1 is a 5V, low-power (300mW), narrowband (3kHz) VHF FM transmitter module. With a simple antenna, the range will be around 6 miles (9.65km). Since this is a “bare” transmitter, the data input must be properly modulated and formatted. There are several Arduino software packages that can do this.
Note: Because it uses amateur radio frequencies, you will need an amateur radio license to use the HX1. It’s easy (and fun!) to get one.
Frequency: VHF FM 144.390MHz fixed (2-meter amateur band)
Supply voltage: 5V at 140mA when transmitting
Input logic level: 5V (EN and TXD)
RF output: 300mW (24.7dBm)
Antenna impedance: 50 ohm
Bandwidth: 3kbps NRZ
Dimensions: 1.7″ x 0.6″ x 0.2″ (43mm x 15mm x 5mm)