•  A strange buzzing signal has been repeating endlessly on the frequency of 4625 kHz since the mid-1970s
• In 2025, the Buzzer’s activity spiked dramatically, including transmissions during a phone call between Russian President Vladimir Putin and US President Donald Trump in February

MOSCOW 

Since the mid-1970s, radio enthusiasts have been captivated and mystified by a strange, buzzing signal repeating endlessly on the frequency of 4625 kHz. It has no official name, no known operator, and no clearly stated purpose. But it has earned a nickname that echoes its persistent sound: the Buzzer.

“No one knew its purpose, but intrigued enthusiasts kept monitoring the frequency, hoping to one day uncover the mystery behind these transmissions,” said Maxim Vilkov, a historian and the person responsible for the Journal of Russian and East European Historical Studies, in an interview with Anadolu.

The signal first gained notoriety for its monotonous buzz tone that played around the clock. That changed in 1995. “In 1995, the radio frequency started transmitting words that appeared to be either meaningless nonsense or coded messages,” Vilkov explained.

The structure of the transmissions has remained oddly consistent. Alongside the buzzing, listeners began hearing strings of seemingly random information: four letters, four digits, a word spelled out letter by letter, and then another alphanumeric sequence.

“The coded words occasionally have actual meaning, but more often they’re just random letter combinations,” Vilkov said.  

A buzzing 2025

Yet that randomness is part of what makes the Buzzer so compelling: It does not follow a schedule and might remain dormant for years, buzzing monotonously, and then suddenly erupt into activity.

“What’s particularly interesting is the complete lack of pattern in these transmissions,” Vilkov continued. “The station might remain silent for years, broadcasting only the buzzing signal, then suddenly transmit as many as 24 words in a single day, like it did in 2008.”

In 2025, the Buzzer’s activity spiked dramatically. While its purpose remained unknown, the sudden increase offered observers a fresh lens, particularly in relation to political and military developments.

“This surge in activity sparked particular interest in the specific words being broadcast,” Vilkov said. “It even became something of a game – people would try to interpret their meanings and predict political developments based on them.”

Several of the transmissions appeared to coincide with notable moments in Russian military operations.

One example came ahead of the launch of Russia’s advanced Oreshnik missile, when the Buzzer transmitted 12 words in a single burst. Another followed during mass drone strikes on Ukrainian military positions, when the station broadcast the cryptic words “bezzlobie” – meaning “absence of evil” – and “khryukostyag,” a hybrid of the Russian onomatopoeia for a pig’s oink and an archaic word for “banner.”

The Buzzer also stirred curiosity during diplomatic events.

When Russian President Vladimir Putin and US President Donald Trump held their first phone conversation in February, the station transmitted two highly unusual words: “blefopuf” – possibly a variation of “bluff” – and “boltalka,” which means “chatter.”  

Theories abound, but ‘no definitive answer’

As global curiosity around the station intensified, so too did efforts to uncover its origins. But decades later, the mystery remains intact.

“Unfortunately, there’s no definitive answer about its purpose,” Vilkov admitted.

One of the most alarming theories links the Buzzer to Perimeter, the Cold War-era nuclear retaliation system known in the West as Russia’s Dead Hand mechanism.

This system was designed to ensure a second-strike capability even if Russia’s military command was wiped out in a nuclear attack.

But Vilkov is unconvinced: “Skeptics rightly note that such a system would require constant transmission, with any interruption potentially triggering launches. Yet the Buzzer frequently goes silent for days at a time, which would be unacceptable for a fail-deadly system.”

Other theories have circulated in the West. Some speculate the Buzzer is a tool for covert communication – perhaps a channel used by Russian intelligence to transmit instructions to operatives abroad.

Yet official responses have been sparse, with Russian authorities typically brushing off the subject. Questions about the Buzzer are often treated with the same derision as UFO sightings.

Just one notable exception exists. “Only Andrey Kartapolov, chairman of the State Duma’s Defense Committee, has acknowledged it,” said Vilkov.

Kartapolov said UVB-76 – the designation often associated with the Buzzer – “serves an important national defense function unrelated to the Perimeter system,” he added.

A more grounded theory places UVB-76 within a broader global context, as one of many so-called “numbers stations” – shortwave broadcasts believed to be used for encrypted, one-way communication to intelligence personnel.

Vilkov said it is known for certain that similar systems are used by a raft of countries, including Russia and the US.

Despite these parallels, the Buzzer’s character is distinctive. Its eerie consistency, the occasional injection of absurd or poetic-sounding words, and the total lack of confirmation about its origin have turned it into a pop-culture legend among shortwave radio hobbyists and conspiracy theorists alike.

“That calm voice cutting through the static to announce words like ‘bezzlobie’ and ‘blefopuf’ continues to captivate listeners,” Vilkov concluded. “Whatever its true purpose, the Buzzer’s transmissions will likely fuel speculation and wonder for years to come.”