Image: Current ZS1I test setup (Click on image for larger view.)
As mentioned before I am busy gearing up for the next 6 Meter DX Season soon to open in South Africa. There is little to no activity in the Mossel Bay, Southern Cape area where I live. So why not create activity? I decided to embark on "The ZS1I - 6 Meter Magic Band Project in the Southern Cape Area of South Africa". I am currently getting my equipment ready for this venture.
Now one need a few handy "tools" to assist you in "playing" on the 50 Mhz band. In future articles I will explain what I am using and how I set it all up. Apart from a radio, computer, firmware, antennas etc. I was looking for an easy and relative cheep way to spot openings on the 6 Meter band and also to monitor WSPR signals. The setup must be fully automated and be able to send spots to WSPRNET. Another must have was the function to use a Telegram phone alert bot that pushes an instant notification to my smartphone the exact millisecond the monitor intercepts an opening on 6 Meters.
Now what is a Compact Low Power Automated WSPR Monitoring Station?
An automated WSPR Monitoring Station is a compact, low-power radio receiver setup. It listens for specific Weak Signal Propagation Reporter (WSPR) radio signals transmitted by amateur radio operators globally.
Image: Raspberry Pi Zero 2 W (Click on image for larger view.)
Here is a breakdown of what it is and what it is used for:
What It Is
- The Brain: A Raspberry Pi Zero 2 W microcomputer running automated listening software like rtlsdr-wspr or WSJT-X.
- The Operation: It runs 24/7, automatically tuning to specific radio frequencies, decoding digital WSPR signals, and uploading the data to the internet via Wi-Fi.
What It Is Used For
- Atmospheric Testing: It measures how well radio waves travel through Earth's ionosphere at any given moment.
- Antenna Benchmarking: It helps operators see how well their antennas perform by checking if their signals can reach your station.
- Space Weather Tracking: It monitors how solar flares, sunspots, and day/night cycles affect global radio communications.
- Data Crowdsourcing: It automatically uploads reports to WSPRnet, contributing to a live, global map of radio propagation.
- Catching Band Openings: It acts as an early warning system, instantly detecting when changing atmospheric conditions suddenly allow signals to travel thousands of kilometers on a previously "dead" frequency.
Here is how the system works from the antenna to your phone.
Image: RTL SDR Receiver V4 (Click on image for larger view.)
1. Recording the Spots
- The Radio: Your SDR dongle constantly listens to a set radio frequency (like 14.0956 MHz for the 20-meter band).
- The Software: Digital software on the Pi cuts the audio into strict two-minute windows.
- The Decode: The software processes the audio to extract the caller's call sign, grid square, and signal strength.The Local Log: Every successfully decoded message is instantly written to a local text file called ALL_WSPR.TXT.
2. Sending Spots to WSPRnet
- The Upload: Right after writing to the local log, the software uses your Wi-Fi to bundle the data.
- The Network: It sends an automated internet request to the central WSPRnet database.
- The Map: Your station’s data joins thousands of others to update global propagation maps in real time.
Image: Telegram Bot (Click on image for larger view.)
3. Connecting Smartphone Push Alerts (Telegram)
To get instant alerts when a specific distance or rare call sign is logged, you connect a custom script to your log file:
- Create the Bot: You message @BotFather on Telegram to create a free bot and get an API Token.
- Get Your ID: You message @userinfobot to find your personal Telegram Chat ID.
- Monitor the Log: You run a lightweight Python or Bash script on the Pi that actively watches (tails) the ALL_WSPR.TXT file for new entries.
- Trigger the Alert: The script checks each new line. If it meets your criteria (e.g., a signal from > 5,000 km away), it sends a web request to Telegram, and your phone buzzes instantly.
Beneath is a few decodes on 40 meters run with the current test setup:
Images: Decodes (Click on image for large view.
I have ordered a few "goodies" that will be used to complete the project. In Part 2 we will be looking at the setup and use of the WSPR Monitoring Station. I will also look at setting up an automated band monitor for FT8. Very similar to the WSPR Monitoring Station except that we need much more processing power and a wider bandwidth. More on this in a future posting.
