In the United States there are no broadcast stations operating below the AM band, though non-directional beacons, time stations and military communications are transmitted in the so-called longwave band that sits below 535 kHz. Longwave has been used for broadcasting in Europe and the Middle East for decades, but it’s a fact I’d sort of forgotten until this week when I learned about the backlash to plans by Irish state broadcaster RTÉ to end its longwave service in just a few weeks.
One of the advantages of longwave is somewhat greater propagation at both day and night as compared to the mediumwave band, which is what AM is called outside the US. (The reason why other countries don’t call it the AM band is because the abbreviation stands for Amplitude Modulation, which is the name for the broadcast technology, which is also used on the longwave and shortwave bands.)
The Irish Post quotes a listener from Nottingham, England who says the only RTÉ service he can receive in his car is longwave, and, “I certainly do not want to listen to it on my computer.” Nottingham is over 200 miles away, and across the Irish Sea, from the transmitter’s location in County Meath, Ireland.
Since 2002 the longwave service has broadcast RTÉ Radio 1, which features mixed music and talk programming intended for a nationwide audience, also broadcast on FM in Ireland. The head of RTÉ Radio 1 estimates that no more than 2,000 people listen to the longwave broadcast. Aside from longwave RTÉ radio is available in Britain on satellite TV provider Freesat and online.
The 252 kHz station was originally used for a joint venture between the RTÉ and Radio Luxembourg, which from 1989 to 2002 broadcast the 24-hour Atlantic 252 service of pop and rock music modeled after American commercial radio. Aimed primarily at the UK audience, Atlantic 252 declined in popularity over the course of the 90s as better sounding FM competitors came about.
Many countries, including France, Turkey, Iceland and Germany, still broadcast on longwave, while Russia ended its broadcasts on the band in January of this year. The BBC also continues Radio 4 broadcasts on longwave in the UK at 198 kHz.
