The Pip

Around 1990 the marker on 4625 kHz changes character: the short high 'pip' of the 1980s gives way to the droning buzz that gives the station its lasting name. The change is undocumented and unexplained, like almost everything about it.

Boender begins his long-running 'Numbers & Oddities' newsletter and logs, cataloguing the strange utility signals, buzzers, pips, geese and squeaky wheels, that share the shortwave bands with the spoken number groups.