198 kHz BBC Radio 4 Longwave (500 kW Droitwich Transmitting Station)
198 kHz Longwave is the crown jewel of British broadcasting history. Transmitting from the gigantic mast radiators at Droitwich with 500 kilowatts of power, its ground wave blankets the entire United Kingdom and North Sea.
198 kHz BBC Longwave
Longwave (LF Broadcast) • LF (Low Frequency) • AM Mode
- Modulation Standard
- Amplitude Modulation (AM) with phase-modulated 50 baud data subcarrier
- Channel Grid / Bandwidth
- 9 kHz LF Broadcast allocation
- Transmitter Power (Typical)
- 500,000 Watts (500 kW AM)
- Polarization
- Vertical T-antenna mast radiator (213m high)
- Signal Propagation Mode
- Ultra-low attenuation ground wave
- Typical Broadcast Range
- Entire British Isles, Ireland, France, Low Countries, and North Sea
Carries BBC Radio 4 programming, the revered daily Shipping Forecast for mariners, Test Match Special cricket commentary, and acts as the official fail-safe "letters of last resort" radio check for Royal Navy Vanguard nuclear submarines.
- Listen at 00:48, 05:20, 12:01, and 17:54 UK time for the soothing, rhythmic reading of the Shipping Forecast gale warnings and coastal station reports.
- The 198 kHz carrier is maintained to extreme atomic precision and was long used as an off-air frequency standard.
Frequently Asked Questions about 0.198 MHz
Why is BBC Radio 4 Longwave famous in naval history?
Royal Navy submarine commanders are instructed that if BBC Radio 4 on 198 kHz stops broadcasting for several consecutive days, it may indicate Britain has suffered a catastrophic nuclear strike, triggering instructions in the letters of last resort.
What is the Shipping Forecast heard on 198 kHz?
The Shipping Forecast is an iconic meteorological bulletin issued by the Met Office on behalf of the Maritime and Coastguard Agency, covering sea areas around the British Isles (Dogger, Fisher, German Bight, Fastnet, etc.).