German Teletype (RTTY) Weather on HF (Shortwave) Radio - DDH9 - 20240623 22:33UTC

This is a video of the German Weather Broadcast from DWD, Hamburg, on shortwave (HF), using teletype (RTTY). I demonstrate two decoding software options: JWcomm32 (older), and, FLdigi. Note the in FLdigi, the "Reverse" feather is selected to properly decode the signal (in either USB or LSB, you still need to select, "Reverse").

The radio used to receive these weather bulletins is an Icom IC-7610, using an antenna designed for 160 Meters.

RTTY is a system for broadcasting text over radio. The technology dates back to the late 1950s and seems somewhat anachronistic. Speeds are slow, even slower than NAVTEX. A similar service is the USCG service, SITOR (Simplex Teletype Over Radio) providing offshore and coastal forecasts over very wide and remote areas from the tropics to the polar regions.

There is dedicated equipment to receive RTTY and SITOR but we can receive both using a standard HF/SSB receiver with software packages such as TRUETTY and SEATTY to decode the signals.

The main advantage of RTTY/SITOR is the reception of information over an entire ocean area. The USCG also shares frequencies across multiple transmitters according to a schedule, rather like NAVTEX. The system is available over the Atlantic and Pacific including polar regions not served. For more about SITOR see the Monitoring Times link or the USCG site.

Around Western Europe and the Mediterranean, the Deutscher Wetterdienst (DWD) , the German Weather Service has accepted the responsibility to broadcast weather information for mariners on RTTY. Frequencies are in the table on the webpage at:
https://weather.mailasail.com/Franks-Weather/Radio-Teletype-Weather-Broadcasts

This video captures the RTTY transmission on 14467.3 kHz (with adjustment in the passband to center on Mark and Space as seen in the video).

DWD (Hamburg) Broadcast Content:

Some broadcasts are of raw weather observations in a WMO coded form.

Otherwise, for the broadcasts include,

+ Strong wind, gale and storm warnings for German Bight, Western and Southern Baltic Sea, German North Sea and Baltic Sea coast

+ Weather forecast for the North Sea and Baltic Sea, Weather situation, forecast valid for 12 hours and outlook valid for another 12 hours

+ Weather report German North Sea and Baltic Sea coast, Weather situation and forecast valid for 12 hours.

+ Navigational warnings for North Sea, Baltic Sea and German coast

+ Weather report Norwegian Sea and Baltic Sea Route North Cape - Shetlands, The Quark - Gulf of Finland. Weather situation and time series forecast for 2 days

+ Weather report North Atlantic. Route Pentlands - Southwest Greenland. Weather situation and time series forecast for 2 days

+ Station reports North Sea and Baltic Sea

+ Weather report Western European Sea. Route Southern Ireland - Area Canarias. Weather situation and time series forecast for 2 days

+ Medium range weather report North Sea, Weather situation and time series forecast for 5 days

+ For the Mediterranean there are Station reports Mediterranean Sea

+ Weather report Mediterranean Sea (in German), Weather situation and forecast valid for 24 hours.

+ Alborán - Tunis. Weather situation and time series forecast for 2 days

+ Weather report Eastern Mediterranean Sea (in German). Route Eastern Tunis - Rhodes/Cyprus. Weather situation and time series forecast for 2 days

+ Medium range weather report Mediterranean Sea (in English), Weather situation and time series forecast for 5 days

+ Around the North Sea and the Baltic this service is a useful supplement to NAVTEX. Particularly so are the 5 day outlooks, These give wind forecast every 12 hours for the 5 day period. The values are straight from the DWD NWP model at a few grid points although these are sufficient to give an overall view and much quicker to receive than synoptic charts on radio fax.

In the Mediterranean, most valuable is the 5 day forecast which seems to be used and very highly regarded by the majority of serious cruising yachtsmen. It is a most valuable service for predicting the major strong wind systems such as Mistrals, Libeccios, Tramontanes, etc. Such winds are usually well predicted 4 and often 5 days ahead. Conversely, I have never found the 24 hour forecast to be much use. For this period, the French, Spanish and even the Italian NAVTEX broadcasts are to be preferred.

73 de NW7US