by Dan Greenall

A half century ago, the BBC World Service used a number of different interval signals.   A few minutes prior to the start of a broadcast, a recognizable, often repeating tune would be played that would enable listeners to more easily locate the BBC in a crowded band on a typical analog receiver.

A peek into the 1975 World Radio TV Handbook notes a few of these.  There was the Morse signal V (as in, V for Victory), primarily used for broadcasts to Europe.  It was also identified as 4 notes tuned B-B-B-E, and an example can be found on Jerry Johnston’s page of shortwave interval signals:

https://www.iaswww.com/swmp3/intervalsignals/simple_is.php

Next, a version of the children’s nursery rhyme “Oranges and Lemons” was used during the 1970’s, and I  have managed to save a recording of it here:

https://archive.org/details/oranges-and-lemons_202510

Then, there were the three notes “B-B-C” in tonic scale.  This was assigned to the World Service for Africa and other services.

Finally, though not listed in this edition of the handbook, was the highly recognizable sound of the Bow Bells. This one came into common use during World War Two when it was broadcast as a symbol of hope for the people of Europe.  At least one source states that the original recording was made in 1926, now 100 years ago.  Many recordings of the Bow Bells interval signal can be found online via YouTube.

More recently, many of the BBC World Service broadcasts seem to start up very abruptly.  An open carrier appears on the frequency to be used only minutes, or even seconds, before the program (already in progress) begins. One example is noted in this recording made on February 5, 2026, just prior to 2200 UTC sign-on, on a frequency of 11645 kHz.

However, two of the above-mentioned tuning signals appear to still be occasionally in use.  The three-note B-B-C was observed on March 4, 2026, at 0028 UTC on 7445 kHz. This recording was made through a Kiwi SDR on the island of Cyprus.

I also logged them using their Bow Bells interval signal on December 28, 2025 at 2358 UTC on 6155 kHz while listening on a Kiwi SDR in Thailand.  Here is how they sounded then.

As well, SRAA reporter Paul Walker noted reception of the Bow Bells back in September 2025 on 9410 kHz.  Follow this link to his report:

https://shortwavearchive.com/archive/bbc-world-service-carrier-and-interval-signal-september-19-20-and-25-2025?rq=paul%20walker

I would be curious if other listeners have heard any of these interval signals recently preceding   BBC World Service broadcasts.