The BBC’s famous Long Wave (LW) radio broadcasts are being kept in existence by a small number of glass valves and the service will cease once they reach the end of their life, it has been reported.

The Guardian newspaper reports that the BBC has bought up every known valve of the correct type it can get its hands, and could now be down to its last 10.

The service requires pairs of the valves to transmit its service on 198 kilohertz Long Wave from the BBC’s famous Droitwich, Worcestershire site and its landmark 700 foot-high radio masts.

The valves aren’t easy or cheap to get hold of but what is really sinking the service is the BBC’s willingness to keep paying for it in the medium and long term in the light of financial cuts announced by the organisation last week.

Currently the service is used for an eccentric collection of programmes including cricket test matches, coverage of Parliament and shipping forecasts and it is the latter as much as anything that explains the point of keeping the service; long wave radio signals propagate reliably over long distances, especially at night and regardless of the weather, which is good for remote shipping.            

The number of listeners is tiny compared to FM, AM and DAB services operated by the BBC and is seen as a hangover from the radio systems of the past.

"This is technology that is becoming obsolete. Digital radio now reaches 97 percent of the population, and there is plenty time to find new homes for long wave-only programmes," Radio 4 network manager Denis Nowlan told The Guardian.

On that note the Government is supposed to switch over completely to DAB from analogue radio by 2015, or when 50 percent of the population is using the technology, whichever comes first. With DAB listening rates stuck somewhere between 15 percent and 25 percent, this looks likely to take longer than originally envisioned.