The Buzzer

The Buzzer broadcasts a continuous repeating buzzing tone on 4625khz. Sometimes this is interrupted by number station type messages in Russian. The original call sign is UVB-76 (technically UZB-76), but the current call sign is ZhOUZ.

The station was branded as "MDZhB" (Russian: МДЖБ) in 2010, which stands for "Mikhail, Dmitri, Zhenya, Boris". And then it rebranded in 2015 as "ZhOUZ" (Russian: ЖУОЗ), which stands for "Zhenya, Ulyana, Olga, Zinaida".

Likely not to be a number station

Apparently the station is mostly for testing that the communications personnel of the receiving sites are awake.