6 bips as transmitted on the BBC since the year 1972. It is a sine wave of frequency 1 kHz. More info: www.miketodd.net/other/gts.htm. Duration: 00:06.
6 bips as transmitted on the BBC from the year 1924 to 1971. It is a sine wave of frequency 1 kHz. More info: www.miketodd.net/other/gts.htm. Duration: 00:06.