Real-time S-Meter monitoring for Elecraft K4 to identify and characterize RFI noise sources.
# Install dependencies
python -m pip install -r requirements.txt
# Run (replace COM9 with your port)
python K4_smeter.py COM9Output:
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- Hardware: Elecraft K4 with USB connection
- Software: Python 3.x, Windows 11 (tested)
- Configuration: K4 PC2:DTR must be set to NONE (prevents PTT keying)
- Polls S-Meter every 10 seconds
- Displays timestamp and dBm readings
- Configures K4 for consistent RFI measurement (CW mode, AGC off, max RF gain)
- Graceful shutdown on Ctrl+C
- Simple error handling (prints "error" on timeout, continues)
- K4_smeter.py - Simple terminal logger (10s polling)
- K4_splot.py - Real-time plotter with 24-minute rolling window (1s sampling)
CRITICAL: Must configure before first run to prevent transmitter keying
- K4: CONFIG → RS-232 → PC2
- Set DTR → NONE
- Verify baud rate: 115200
Windows Device Manager:
- Look for "Silicon Labs CP210x USB to UART Bridge (COMn)"
- Note the COM number (e.g., COM9)
| Issue | Solution |
|---|---|
| K4 transmits on script start | Set PC2:DTR to NONE in K4 menu |
| Port in use | Close N1MM, WSJT-X, or other CAT software |
| "error" readings | Check USB cable, verify K4 powered on |
| "python not found" | Reinstall Python with "Add to PATH" checked |
- Master Plan - Complete technical specification
- Development Guide - Claude prompt instructions
- Architecture - System diagram and data flow
MIT License - See LICENSE file
Amateur radio RFI monitoring project by Extra class operator