DiscoverScroll article

UVB-76 (Russian: УВБ-76; see § Name and callsigns for other callsigns), also known by the nickname "the Buzzer", is a shortwave radio station that broadcasts in upper sideband mode on the frequency of 4625 kHz (wavelength of 64.8 m).

It broadcasts a short, monotonous buzz tone (), repeating at a rate of approximately 25 tones per minute, 24 hours per day. Sometimes, the buzzer signal is interrupted and a voice transmission in Russian takes place. While its true purpose has never been revealed, the transmission is not related to the Dead Hand system, despite being sometimes referred to as Doomsday Radio. It has been interrupted and stopped many times yet no retaliatory response – nuclear weapons nor Intercontinental ballistic missiles (ICBMs) – has been launched as a result. The best-supported theory is that it is part of a military command network for the Leningrad Military District of Russia.

The UVB-76 signal was first detected by shortwave radio listeners, with the earliest preserved recording from 1982 capturing its repetitive tone on the 4625 kHz frequency.

The station is commonly known as "the Buzzer" in both English and Russian (Russian: Жужжалка, romanized: Zhuzhzhalka). From its first voice transmission in 1997 to 2010, the station identified itself as UZB-76 (УЗБ-76). The callsign UVB-76 was never used by the station itself, but is rather a mistranscription of UZB-76. In the following years of transmission, the main callsign of the station changed regularly. In addition to these main callsigns, the Buzzer also uses other "side callsigns" which are being used less frequently than the main callsign. The signal consists of a buzzing sound that lasts 1.2 seconds, pausing for 1–1.3 seconds, and repeating 21–34 times per minute. Until November 2010, the buzz tones lasted approximately 0.8 seconds each.

The buzzing sound is sometimes interrupted by the broadcast of voice messages. These messages are always given in Russian by a live voice, and follow three fixed formats:

Example of a Monolith message sent on the Buzzer with exactly one callsign, one ID group and one message block (most common type):

Since it has not been heard for years, messages of this type are most likely not being sent on the Buzzer anymore.

Only on very rare occasions have there been any external civilian communications—unless authorised by the Russian defence ministry—with UVB-76, given its status as a military radio. The UVB-76 operator combined three individual transmitters, with one above, one below and the other centre 4625 kHz transmitting MS-5 burst, along with CIS-12 modern audio as well as tones in several states, summarising together a highly dense spectral pattern with the upper-side band.

However, Rimantas Pleikys, a former Minister of Communications and Informatics of the Republic of Lithuania, has written that the purpose of the voice messages is to confirm that operators at receiving stations are alert. There is speculation published in the Russian Journal of Earth Sciences which describes an observatory measuring changes in the ionosphere by broadcasting a signal at 4625 kHz, the same broadcast frequency as the Buzzer. Another theory, described in a BBC article, states that the tower is connected to the Russian 'Perimeter' missile system, and emits a "dead hand" signal that will trigger a nuclear retaliatory response if the signal is interrupted as a result of a nuclear attack against Russia. Like the Buzzer, these stations transmit a signature sound that is repeated constantly, but is occasionally interrupted to relay coded voice messages. This may have been due to a reorganization of the Russian military. Since 9 August 2015, the station is not transmitting from the Kerro Massiv transmitter site ("Irtysh") anymore, possibly due to a reorganization of the Russian military for the particular area which may cause the frequency to be used only in the Moscow Military District.

Quick Facts

• Sometimes, the buzzer signal is interrupted and a voice transmission in Russian takes place.
• It broadcasts a short, monotonous buzz tone (), repeating at a rate of approximately 25 tones per minute, 24 hours per day.
• While its true purpose has never been revealed, the transmission is not related to the Dead Hand system, despite being sometimes referred to as Doomsday Radio.
• The UVB-76 signal was first detected by shortwave radio listeners, with the earliest preserved recording from 1982 capturing its repetitive tone on the 4625 kHz frequency.
• The best-supported theory is that it is part of a military command network for the Leningrad Military District of Russia.

Source material: Wikipedia - "UVB-76". Adapted and summarized for DiscoverScroll. Original contributors are credited through the linked Wikipedia article. Read original on Wikipedia. CC BY-SA 4.0. Changes were made from the original.