Decoders
All decoders
Every decoder in the app, in groups, with a link to its page.
Decoders turn a signal into text or other readable information. They work from the audio you are listening to, so tune to the signal first. A card for the decoder appears on Home when it has something to show. Some results (NAVTEX and weather fax) are also kept in the Library History.
Text signals #
| Decoder | What it reads |
|---|---|
| Morse code | Morse in the CW mode, shown as a one-line strip. |
| NAVTEX | Maritime safety messages on 518 kHz and nearby. |
| RTTY | Radio teletype in USB or LSB. |
| PSK31 | Keyboard-to-keyboard text in USB or LSB. |
| Weather fax | Weather charts from coast stations, drawn line by line. |
Marine #
| Decoder | What it reads |
|---|---|
| DSC calls | Digital calls between ships on marine channel 70. |
Time and navigation beacons #
| Decoder | What it reads |
|---|---|
| Time signals | The time and date from the WWV and WWVH time stations. |
| VOR and ILS | Aviation navigation signals on 108 to 118 MHz. |
| NDB beacons | The Morse name of an aeronautical beacon. |
Tones and digital voice #
| Decoder | What it reads |
|---|---|
| CTCSS and DCS tones | The sub-audible tone or code a two-way radio channel uses. |
| Digital voice: who is talking | Who calls whom on digital voice channels. Never plays the voice. |
What you need #
HF decoders (NAVTEX, weather fax, RTTY, PSK31, most Morse) need a receiver that can tune below about 24 MHz, such as an RTL-SDR Blog V4. Explore says "Needs HF" where this applies.