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The Buzzer – ZhUOZ (Formerly UVB-76)

Waterfall image

Name: The Buzzer („Жужжалка”)
Callsign: ZhUOZ
Former Names: UVB-76, UZB-76, MDZhB
Country of Origin: Russia
Voice Summary: Male/Female live voice
Frequency: 4625 kHz/ 6998 kHz (since November 2015)
Mode: AM with suppressed LSB, voice messages can be in USB, or LSB
Counterpart Stations: The Squeaky Wheel, The Pip

Station Summary

This Station was first spotted in the late 70’s and is known for its constant buzzing (1.25s buzzing, then 1.85s pause). The buzzing tone acts as a channel marker to keep the frequency always in use for emergencies, and it can also be used for propagation measurements. The Buzzer used to have the ENIGMA ID S28 although it is not a numbers station. From February 18-26th, it used a temporary night frequency (assumed) on 3216 KHz.

During the years of activity the callsign has been changed. It was known first as UVB-76 although incorrectly as it was UZB-76 (УЗБ-76) as noted in recordings.[6] In 2010 it changed its callsign to MDZhB (МДЖБ). On January 2016 its changed its callsign to ZhUOZ (ЖУОЗ). [7]

The sound of the station today has changed much since it was first discovered.  At one point The Buzzer used to change to a continuous buzz one minute before the hour, and until November 2010, its tone lasted slightly longer (about 0.8 seconds).


The station works as a communications center within the Western Military District that sends codes to corresponding military units and their outposts.  The buzzer transmits continuously through the day, however due to the propagation issues in Western Europe and especially in Northern America, it is problematic to receive during daylight time.

UVB-76 The Buzzer Report articles summarize messages and show important events from 2012-2016:
2012 – 2013

Voice Messages

Sometimes the marker drops and a live voice message is read. The usual voice message format is [Callsign] 58 151 [Codeword] 39 51 65 78 The callsign and the Codeword is spelled out in Russian phonetic alphabet.  (UVB-76 is the pre-movement callsign, the new callsign is MDZhB)

The specific format that the messages are sent in is known in Russian military terminology as “monolyth (монолит) messages”. They are scrambled messages sent live between the radio communication headquarters and subordinate military unit. The purpose for these messages varies between testing the readiness of the unit, training, issuing warning messages and call for mobilization.

In theory the codebook lies in a sealed envelope in a special safe with instructions. For different communication centers have different callsigns, codes and instructions for each military branch. The Russian intelligence agencies FSB, GRU and SVR don’t use such a system, instead it uses only numbers.

See this page for recorded samples, includes primary formats and special messages.

Monolyths are constantly changing, the same monolyth could mean a different thing over time. It’s not a coded message but an order for instance the “BROMAL” – first recorded message could mean either full combat readiness or full withdrawal.

Messages with more than one codeword are sometimes observed and messages with no end numbers after the codeword are rarely spotted.  There has been observations of radio operator sending message incorrectly and then says “sboj” (error) that proves the message is read live.

See this page about the Russian military message types used by Buzzer and its counterparts.


Buzzer Harmonic EM Dissipation’s

There has been observations of Harmonic EM dissipation (when energy waves are getting weaker in equal steps) from Buzzer antenna. When Buzzer frequency is tuned in CW mode the Harmonic EM dissipation can be heard. Every time the antenna transmits, it also inadvertently creates a harmonic rebounding EM. The issues of the buzzer equipment create unintentional signal carriers. The buzzer sound itself consists of a sequence  of frequencies that are 2x of previous so considering they are nicely laid out, they create temporary carriers that last only the time of the buzz itself. If the listener has a receiver that is tuned well enough, he can pick up in them the surrounding bandwidth. This phenomenon tends to occur more on antennas that are not well grounded

Recording by Seth Weiner KC2UXD


  • Current Location

It’s known, judged by radio observation that at least two transmitter sites exist. 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,[3] that serves as the main staff headquarters of the Western Military district in Moscow.

Image of the Towers and Antennas
Incoming View From the Road
Possible 2nd Site at Naro-Fominsk
Someone walking into The Buzzer site
Main Control Building
Larger view with the gate in sight
The Russian Military Districts


  • Former Location

The first known location of UVB-76 was Povarovo in the Moscow district at 56°5′0″N 37°6′37″E [3]However, since 2010 the site has been abandoned possibly due to the 2010 Russian military reform that combined the Leningrad military district and the Moscow military district into one Western military district.  A sample logbook left behind during the move shows the daily work schedule of the station in 2005. [Radio Scanner…]

Recreation of the Buzzer signal using FL Studio


Buzzer signal has sawtooth waveform, and its strong harmonics often serve the role of unintentional carriers, that give a glimpse of bandwidth in UVB-76 area.



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