The Buzzer (ZhUOZ MDZhB UZB76)

The Buzzer (NZhTI ANVF ZhUOZ MDZhB UZB-76)
Frequencies	4.625 MHz,6.998 MHz
Frequency Range	4.625 MHz - 6.998 MHz
Mode	AM
Modulation	USB
ACF	—
Emission Designator	—
Bandwidth	2.8 kHz
Location	Russia
Short Description	The Buzzer, call-sign NZhTI (formerly ANVF, ZhUOZ, MDZhB and UZB-76), is a Russian Military Commandment system signal used to broadcast diplomatic ciphered messages known as "monolit" to the russian navy. If there is no message to broadcast, its "homing" signal is a loud ship-horn buzzing sound. It is believed to serve a similar purposes to The Alarm and The Air Horn.
I/Q Raw Recording	—
Audio Sample

The Buzzer, call-sign НЖТИ (NZhTI), nicknamed Жужжалка, formerly known by its previous callsigns АНВФ (ANVF), ЖУОЗ (ZhUOZ), МДЖБ (MDZhB) and УЗБ-76 (UZB-76), is a Russian-based military station that frequently broadcasts Monolit format messages in Russian. Its official name is actually вулкан (Vulkan, Volcano in English). Its trademark buzzer is constantly transmitted while there is no message to broadcast. Active since the late 1970s.

NZhTI is an analogue Upper Side Band voice signal. It has an active carrier at 4625 kHzKiloHertz (kHz) 10^3 Hz. It is believed that the buzzer is not directly modulated but actually recorded by a active microphone, as there have been reports of hearing background chatter while the buzzer was on.

Click Here to Hear The Buzzer Live at WebSDR Univ. of Twente[edit]

Updates[edit]

On September 7, 2010, The Buzzer changed its callsign from УЗБ-76 (UZB-76) to МДЖБ (MDZhB)

Since October 15, 2015, The Buzzer has been seen transmitting in parallel on a new frequency 6998 kHzKiloHertz (kHz) 10^3 Hz, while still transmitting on 4625 kHzKiloHertz (kHz) 10^3 Hz.

On December 28, 2015, The Buzzer has changed its call-sign to ЖУОЗ (ZhUOZ).

On March 1, 2019, The Buzzer has changed its call-sign to АНВФ (ANVF).

On December 30, 2020, The Buzzer has changed its call-sign to НЖТИ (NZhTI).

On January 19, 2022, the two sites became active in sending out the monolit ciphers to the navy for a planned upcoming invasion of the Ukraine. A news article from Mirror also proves this activity as being a part of this invasion:

https://www.mirror.co.uk/news/world-news/six-russian-war-landing-ships-25992846

Location[edit]

At least two transmitters exist for NZhTI. One is confirmed to be at 60°18’40.1″N 30°16’40.5″E where it sends radio relay and phone lines directly from Moscow via St. Petersburg's command hub on Palace Square.

The other site is claimed to be located at Naro-Fominsk, Moscow district at 55°25’35″N 36°42’33″E where the 69th communications center is located, which serves as the main staff headquarters of the Western Military district in Moscow.

The Buzzer:

Example of Voice Messages on ZhUOZ: