UVB-76

UVB-76, also known by the nickname "The Buzzer", is a shortwave radio station that broadcasts on the frequencies 4625 and 4810 kHz. It broadcasts a short, monotonous , 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. The start date of broadcasting is disputed. However, it was allegedly reported to start broadcasting sometime in the 1970s.
Name.
The station is commonly known as the Buzzer in both English and Russian (). From the start of broadcasting to circa 1978, the station identified itself as UYB-76 (Russian: УЫБ-76). From 1978 to 2010, the station identified itself as UVB-76 (), and it is still often referred by that name. In September 2010, the station moved to another location and adopted the identification MDZhB (). On December 28, 2015, the station began using the callsign ZhUOZ () – pronounced "Zhenya, Ulyana, Olga, Zinaida". Since March 1, 2019, the station appears to have used a number of new callsigns, the most recurring of which is ANVF().
Format.
The station transmits using AM with a suppressed lower sideband (USB modulation), but it has also used full double-sideband AM (A3E). 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. One minute before the hour, the repeating tone was previously replaced by a continuous, uninterrupted alternating tone, which continued for one minute until the short repeating buzz resumed, although this stopped occurring in June 2010.
Since the start of broadcasting sometime in the 1970s, the buzzer broadcast as a repeating two-second pip, changing to a buzzer in the late 1980s/early 1990s. It briefly changed to a higher tone of longer duration (approximately 20 tones per minute) on January 16, 2003, but has since reverted to the previous tone pattern. These buzzes have gotten longer in duration and deeper in pitch over time, and breakdowns have been more frequent, suggesting the possibility of the buzzes being mechanically generated. In one instance of a breakdown in 2016, a person can be heard beating the mechanical buzzer to make it work again, implying that there is normally 24/7 monitoring of the transmissions.
Voice messages.
Sometimes the buzzing sound is interrupted and a voice message is broadcast. These messages are usually given in Russian by a live voice, and follow a fixed format. An example of such a message:
At 21:00 UTC on December 24, 1997:
 Ya UVB-76, Ya UVB-76. 180 08 BROMAL 74 27 99 14. Boris, Roman, Olga, Mikhail, Anna, Larisa. 7 4 2 7 9 9 1 4
Voice messages were thought to be very rare, until 2010 when listeners reported increased activity of the station, spurring on further monitoring and allowing listeners to "catch" more of the messages which would have otherwise gone unnoticed. On June 5, 2010, UVB-76 went silent for approximately 24 hours, resuming the normal buzzing pattern on the morning of June 6. At 13:35 UTC on August 23, 2010, a voice message was broadcast:
 UVB-76, UVB-76. 93 882 NAIMINA 74 14 35 74. 9 3 8 8 2 Nikolai, Anna, Ivan, Mikhail, Ivan, Nikolai, Anna. 7 4 1 4 3 5 7 4
On October 17, 2016, The Buzzer broadcast at least 18 different messages in less than 24 hours.
Apparently, since around the beginning of 2020 more frequent messages have been heard.
Four voice broadcasts could be heard between January 13 and January 27, 2020.
On May 11, 2020, two messages were heard, one at 13:11 UTC and a second one at 15:22 UTC.
On May 14, 2020, another two messages were broadcast, one at 8:00 UTC and another one at around 10:00 UTC.
On June 17, 2020, two messages were heard, one at 11:39 UTC and a second one at 11:47 UTC:
 VZhTsKh VZhTsKh 10 269 KYeDROKYeKS 99 57 53 14.
 VZhTsKh VZhTsKh 74 701 KON'YuNKTURA 57 55 86 97 VDYeLYVAN'Ye 06 71 29 59.
On June 18, 2020, one message was heard at 10:12 UTC:
 ANVF ANVF 17 042 DAMPOLYaD 75 79 69 56; 
 ANVF ANVF 17 042 DAMPOLYaD 75 79 69 56.
On July 1, 2020, one message was heard at 12:31 UTC:
 VZhTsKh VZhTsKh 217O 217O 88 498 79 789 KAINOGON 52 47 37 68;
 VZhTsKh VZhTsKh 217O 217O 88 498 79 789 KAINOGON 52 47 37 68.
On July 8, 2020, from 07:40 UTC to 14:40 UTC, the buzzer broadcast 13 different messages.
On July 30, 2020, three messages were heard, one at 11:20 UTC, a second one at 12:16 UTC and the third message at 13:14 UTC:
 ANVF ANVF 18 844 BRYZGALKA 94 96 27 09 ATOLLOVYJ 60 76 53 11;
 ANVF ANVF 18 844 BRYZGALKA 94 96 27 09 ATOLLOVYJ 60 76 53 11.
 ANVF ANVF 54 400 BAULOBYK 53 57 71 19;
 ANVF ANVF 54 400 BAULOBYK 53 57 71 19.
 ANVF ANVF 77 253 BUKVOYeD 40 68 55 47;
 ANVF ANVF 77 253 BUKVOYeD 40 68 55 47.
On August 3, 2020, one message was heard at 12:45 UTC:
 ANVF ANVF 61 691 KOLOMER 92 80 07 74;
 ANVF ANVF 61 691 KOLOMER 92 80 07 74.
On August 6, 2020, one message was heard at 11:43 UTC:
 VZhTsKh VZhTsKh 217O 217O 34 050 41 065 KARTING 82 17 24 19;
 VZhTsKh VZhTsKh 217O 217O 34 050 41 065 KARTING 82 17 24 19.
On August 9, 2020, one message was heard at 10:45 UTC:
 VZhTsKh VZhTsKh 217O 217O 58 930 78 148 ZABORChIK 84 48 55 97;
 VZhTsKh VZhTsKh 217O 217O 58 930 78 148 ZABORChIK 84 48 55 97.
On August 11, 2020, two messages were heard at 03:22 UTC:
 ANVF ANVF 11 234 LAGOKYuRI 69 69 10 18;
 ANVF ANVF 11 234 LAGOKYuRI 69 69 10 18.
 ANVF ANVF 52 135 KORZhOBAYaN 54 05 29 46;
 ANVF ANVF 52 135 KORZhOBAYaN 54 05 29 46.
On August 12, 2020, one message was heard at 02:17 UTC:
 87O1 87O1 217O 217O 19 611 61 649 BOYeKOKLYeJ 83 62 80 06;
 87O1 87O1 217O 217O 19 611 61 649 BOYeKOKLYeJ 83 62 80 06.
On August 14, 2020, from 02:11 UTC to 08:12 UTC, the buzzer broadcast 13 different messages.
On August 21, 2020, a very long message with 16 callsigns was heard at 17:25 UTC:
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 69 536 32 000 24 664 75 363 81 077 90 617 42 765 89 276 80 984 65 798 07 393 98 234 13 379 16 021 27 767 66 461 68 580 GNYeTOTOR 73 21 86 73; 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 69 536 32 000 24 664 75 363 81 077 90 617 42 765 89 276 80 984 65 798 07 393 98 234 13 379 16 021 27 767 66 461 68 580 GNYeTOTOR 73 21 86 73.
On August 22, 2020, four messages were heard, one at 04:04 UTC, a second one at 10:12 UTC, a third message at 13:07 UTC and a last one at 15:05 UTC:
 VZhTsKh 54 733 KORMOZONT 25 32 86 50;
 VZhTsKh 54 733 KORMOZONT 25 32 86 50.
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 97 079 72 005 88 147 07 542 53 273 10 004 68 520 00 169 66 800 45 344 93 229 13 776 40 817 98 387 12 217 99 994 06 523 DUDOChNIK 85 29 05 64;
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 97 079 72 005 88 147 07 542 53 273 10 004 68 520 00 169 66 800 45 344 93 229 13 776 40 817 98 387 12 217 99 994 06 523 DUDOChNIK 85 29 05 64.
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 16 532 60 735 53 207 40 835 15 923 30 347 55 255 04 470 85 804 11 939 04 194 66 007 50 830 05 109 40 791 41 063 24 537 IKROMYeT 62 77 18 81;
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 16 532 60 735 53 207 40 835 15 923 30 347 55 255 04 470 85 804 11 939 04 194 66 007 50 830 05 109 40 791 41 063 24 537 IKROMYeT 62 77 18 81.
 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 34 532 25 876 72 427 86 875 51 023 84 399 70 719 31 228 14 904 00 193 04 311 15 069 05 852 38 785 39 223 85 666 01 562 GUL'BIShchYe 15 69 48 42; 'M4T 5PTsB LNTM ZhD9S MSZh7 28YA YeDGShch 2GYeTs 7U8T KhIZhJ OMP4 58Shch1 53AJ AMVS 34ShchK V'TD YeIYJ 34 532 25 876 72 427 86 875 51 023 84 399 70 719 31 228 14 904 00 193 04 311 15 069 05 852 38 785 39 223 85 666 01 562 GUL'BIShchYe 15 69 48 42;
On August 24, 2020, one message was heard at 16:28 UTC:
 ANVF ANVF 217O 217O 83 466 95 436 KUMOZhBAN 64 79 23 75;
 ANVF ANVF 217O 217O 83 466 95 436 KUMOZhBAN 64 79 23 75.
Unusual transmissions.
Distant conversations and other background noises have frequently been heard behind the buzzer, suggesting that the buzzing tones are not generated internally, but are transmitted from a device placed behind a live and constantly open microphone. Because of the occasional fluctuating pitch of the buzzing tones, it is supposed that the tones are generated by a tonewheel as used in a Hammond organ. It is also possible that a microphone may have been turned on accidentally. 
One such occasion was on November 3, 2001, when a conversation in Russian was heard:
 Я – 143. Не получаю генератор... ...идёт такая работа от аппаратной.
Below is a log of unusual signals and other anomalies which listeners to UVB-76 have captured;
In September 2010, several unusual broadcasts were observed; these included portions of the buzzer being replaced with extracts from Tchaikovsky's "Swan Lake", and in one instance, a sound that resembled that of a woman screaming.
On November 11, 2010, intermittent phone conversations were transmitted and were recorded by a listener (at 14:00 UTC) for a period of approximately 30 minutes. These conversations are available online, and seem to be in Russian. The phone calls mentioned the "brigade operative officer on duty", the communication codes "Debut", "Nadezhda" (Russian for "hope", both a noun and a female name), "Sudak" (an alternate name for the Zander, and also a town in Crimea) and "Vulkan" (volcano). The female voice says:
 Офицер дежурного узла связи "Дебют", прапорщик Успенская. Получила контрольный звонок от Надежды... ...поняла.
On July 17, 2015, the station broadcast what appeared to be a RTTY signal in lieu of the buzzer.
On February 7, 2019, several transmissions that were likely sent by a third party were broadcast. One of them goes:
 Ya - Pogrom, Ya - Pogrom. Vozduh. 49 832 VOLKOSTYK 12 38 86 52
Notably, through much of 2020, more unusual activity and anomalies was recorded on the buzzer's frequency by listeners as follows.
On May 15, 2020, The Buzzer was interrupted by a third-party transmission, likely sent by French fishermen.
On the same day, about four hours later, The Buzzer began playing Russian music.
On May 17, 2020, UVB-76 (a.k.a. "The Buzzer") was interrupted again by a short third-party transmission. It is suspected to have been sent by the same French fishermen as on May 15, 2020,
On May 30, 2020, at about 20:00 UTC, music was heard on The Buzzer's frequency.
On June 9, two events could be witnessed. At 20:03 UTC, the buzzing generator of UVB-76 broke down; the buzzing continued only a few seconds later. Another anomaly happened at around 21:00 UTC, multiple transmission of morse code (of unknown origin) were heard.
On June 16, 2020, the buzzer stopped at 20:40 UTC for unknown reasons. It returned about one hour later at 21:40 UTC.
On July 15, 2020 a Voice message of unknown origin was heard on 4624.2 kHz, just below the Buzzers frequency. The message didn't come from UVB-76 itself because the buzzing didn't stop. The message was in English and contained only numbers, no letters. The only word that appeared in this message was "Attention“.
On August 16, 2020, from 17:26 UTC to 01:50 UTC, on the buzzer frequency, with occasional moments of pause, there was some music playing and some carrier tones. During the strange occurrence, the buzzer marker never stopped, suggesting a third-party origin, possibly from someone who wanted to disturb the buzzer.
Location and function.
The purpose of the station has not been confirmed by government or broadcast officials. 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. Other explanations are that the broadcast is constantly being listened to by military commissariats.
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 as the Buzzer.
It is also speculated that the voice messages are some sort of Russian/Soviet military communications, however they could also be numbers stations for intelligence agencies such as the FSB or the former KGB of the Soviet Union. The buzzing sound is speculated to merely be a "channel marker" used to keep the frequency occupied, thereby making it unattractive for other potential users. The signature sound could be used for tuning to the signal on an old analogue receiver. The modulation is suitable to be detected by an electromechanical frequency detector, similar to a tuning fork. This can be used to activate the squelch on a receiver. Due to the varying emission properties on shortwave bands, using a level-based squelch is unreliable. This also allows a signal loss to be detected, causing an alarm to sound on the receiver.
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.
There are two other Russian stations that follow a similar format, nicknamed "The Pip" and "The Squeaky Wheel". Like the Buzzer, these stations transmit a signature sound that is repeated constantly, but is occasionally interrupted to relay coded voice messages.
The former transmitter was located near Povarovo, Russia, at which is about halfway between Zelenograd and Solnechnogorsk and northwest of Moscow, near the village of Lozhki. The location and callsign were unknown until the first known voice broadcast of 1997. In September 2010, the station's transmitter was moved to the nearby city of Saint Petersburg, near the village of Kerro Massiv. This may have been due to a reorganization of the Russian military. Prior to August 9, 2015, the station is not transmitted 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. At present, The Buzzer appears to be broadcast only from the 69th Communication Hub in Naro Fominsk, Moscow. In 2011, a group of urban explorers claimed to have explored the buildings at Povarovo to find an abandoned military base and, in it, a radio log record confirming the operation of a transmitter at 4625 kHz.
Other callsigns.
Besides the main callsign, there have been transmissions containing different callsigns such as: LNR4 (Russian: ЛНР4), 87OI (Russian: 87ОИ), VM62 (Russian: ВМ62), A1JZh (Russian: А1ЙЖ), MSZh7 (Russian: МСЖ7), OMP4 (Russian: ОМП4), 7U8T (Russian: 7У8Т), VLHN (Russian: ВЛХН), 217O (Russian: 217О), ANVF (Russian: АНВФ), VZhCH (Russian: ВЖЦХ), LNRCh (Russian: ЛНРЧ), VShchCH (Russian: ВЩЦХ), 34ShchK (Russian: 34ЩК), YeDGShch (Russian: ЕДГЩ), 58Shch1 (Russian: 58Щ1), LNR4 (Russian: ЛНР4), 5Ye27 (Russian: 5Е27), M4Z2 (Russian: М7З2), 'M4T (Russian: ЬМ4Т), 5PTsB (Russian: 5ПЦБ), LNTM (Russian: ЛНТМ), ZhD9S (Russian: ЖД9С), 28YA (Russian: 28ЫА), KhIZhJ (Russian: ХИЖЙ), 53AJ (Russian: 53АЙ), AMVS (Russian: АМВС), V'TD (Russian: ВЬТД), YeIYJ (Russian: ЕИЫЙ).
External links.
Live stream from Wedsdr