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WSPR - Weak Signal Propagation Reporter

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What is WSPR

A WSPR beacon, Weak Signal Propagation Reporter, is a low-power amateur radio transmitter designed to send Weak Signal Propagation Reporter digital signals (pronounced "whisper") across global distances. It typically costs around 45 to 55 GBP and operates on 1–30 MHz with roughly 200mW (23 dBm) of output power.

How It Works

  • Weak-signal decoding: Uses 4FSK modulation to transmit tiny signals well below the noise floor (-28 dB SNR).

  • GPS synchronization: Integrates an active GPS antenna to lock transmission timing precisely to even-numbered minutes.

  • Automatic positioning: Computes your Maidenhead grid locator straight from GPS data without manual setup.

Operating Rules for Foundation Licensees

WSPR is a highly rewarding tool for UK Foundation licence holders, but it requires strict attention to power settings and scheduling:

  • Drastically Reduce Power: The fundamental ethos of WSPR is weak-signal testing. While your licence permits up to 25 Watts PEP, typical WSPR transmissions use between 100 milliwatts and 5 Watts. Transmitting with 25 Watts on WSPR is considered bad practice and can overload local receivers.

  • Automated Beacon Restrictions: Under Section 10 of the UK licence, Foundation holders cannot operate an unattended beacon. You must be present at the controls, meaning you cannot leave WSPR running on your computer while you leave the house or go to sleep.

  • Duty Cycle Management: WSPR requires a continuous 100% duty cycle for 2 minutes straight. Ensure your transmitter or transceiver can handle sustained transmission without overheating, especially if you are using compact QRP radios.

The popular Banggood WSPR Beacon (typically built around an Arduino-based chip, an Si5351 clock generator with TCXO, and a built-in GPS module) operates in a fully automated manner once configured. Out of the box, it defaults to the callsign BG6JJI on the 20m band, meaning you must reconfigure it with your own UK Foundation callsign before legally transmitting.

WSPR (Weak Signal Propagation Reporter) was created in 2008 by Nobel Prize-winning physicist and radio amateur Joe Taylor (K1JT)

Operating Safeguards

As a UK Foundation licence holder, remember that unattended beacons are prohibited. Keep the unit within your operating shack so you can quickly pull the power cable if any unexpected transmission faults or interference occur.

Are you planning to run this beacon into a multiband wire antenna (like an end-fed half-wave), or do you have an external low-pass filter bank ready to swap in for cleaner harmonics when changing bands?

Follow these steps to program and run this specific hardware version:

1. Initial Setup & Hardware Connections

Before connecting the device to power, attach the external elements to protect the RF amplifier circuit:

  • HF Antenna: Connect your resonant HF antenna to the SMA RF OUT connector via a 50 Ohm coaxial cable.

  • GPS Antenna: Attach the included active external GPS puck antenna to the SMA GPS port. Place the puck near a window or outdoors to acquire satellite signals.

  • Data Cable: Plug a USB cable into the device's port (USB-C or USB-B, depending on your generation) and connect it to your PC or laptop.

2. Connect via Serial Terminal

The Banggood beacon uses an internal serial-to-USB chip configured at a default speed of 9600 baud.

  • Open the browser-based application SerialTerminal.com using Chrome or you could download a local program like PuTTY.

  • Select the correct COM port assigned to your USB device.

  • Set the speed to 9600 baud (if your specific variant was updated with alternative firmware, try 115200).

  • Press Enter; you should see the current status or a text response confirming the link

3. Send the Configuration Command

The beacon uses a unified command format sent directly via the serial terminal input bar. The command must be written exactly as follows:

 CONFIG:[CALLSIGN],[GRID],[POWER],[FREQUENCY IN HZ]

Setting the Parameters:

  • CALLSIGN: Your exact amateur radio callsign.

  • GRID: Your Maidenhead grid locator. You can leave this blank if you want the beacon to use its Auto-GPS location tracking feature (it will calculate your grid automatically).

  • POWER: Set this to 23, which matches the hardware’s maximum capability of 23 dBm (roughly 200 milliwatts).

  • FREQUENCY: Enter the exact dial frequency for your chosen band in Hertz.

Target Frequencies (in Hz) for the 2E0ERO Magnetic Loop :

Configuration:

Type your chosen line into the serial terminal bar and press Enter. The terminal will return a confirmation message, and the parameters will save to the device's onboard EEPROM memory, persisting even when powered down.

Last Modified 2026 April 29 - 04:37