Morse Code Background
Edit on GitHubWhy Morse survives: history, the PARIS standard, and why it still fits a rescue beacon
Morse Code Background
Overview
Morse code is nearly 200 years old and still the right choice for a rescue beacon. This page explains why, and the standard the firmware implements.
Why Morse Still Fits
| Requirement | How Morse delivers |
|---|---|
| Lowest common denominator | Decodable by ear or any AM radio |
| No protocol needed | No sync, no handshake, no decoder |
| Robust at low SNR | Human brain integrates weak signals |
| Short messages | SOS is 9 elements - seconds on air |
The PARIS Standard
Timing is calibrated so the word “PARIS” takes exactly 50 units:
- Unit =
1200 / WPMms. - At 13 WPM a unit is 92 ms.
| Element | Units |
|---|---|
| Dot | 1 |
| Dash | 3 |
| Intra-char gap | 1 |
| Inter-char gap | 3 |
| Word gap | 7 |
Pros and Cons vs Digital Modes
| Aspect | CW Morse | Digital packet |
|---|---|---|
| Equipment needed | Any AM radio | Matching decoder |
| Human readable | Yes | No |
| Robustness | Excellent | Good with FEC |
| Battery cost | Minimal | Similar at low rate |