◆ WELCOME TO RADIO SILENCE :: THE COLD WAR NUMBERS STATION ARCHIVE ◆ "If you can hear this, you were meant to." ◆ Last updated: 03 Feb 2024 ◆ Visitor count: 047,882 ◆ NEW: Recording UVB-76-61-1014 added to the archive ◆   
► Welcome to Radio Silence

This site is dedicated to the preservation and study of Cold War-era numbers station recordings. Numbers stations were (and some still are) shortwave radio broadcasts of spoken numbers, letters, or Morse code, used by intelligence agencies to transmit one-time pad messages to field agents. They are one of the strangest and most enduring artefacts of the Cold War.

I've been collecting recordings since 1997, when I first heard something unexplainable on 7812 kHz at 2200 UTC. This site is my attempt to catalogue everything I've found, and everything sent in by the community. All recordings are provided for historical research and educational purposes.

New here? Start with the Station Guide for background, then browse the Full Archive. If you have recordings to contribute, see the About page.

► Featured Recording — UVB-76 Variant, 14 October 1961
Station ID:UVB-76 (variant — pre-standard format)
Date:14 October 1961
Time:21:47–21:49 UTC (approx.)
Frequency:1420.405 MHz
Duration:47 seconds active signal + 14 seconds noise tail
Source:Anonymous donation, received 2019
Format:WAV, 44.1kHz mono (converted from original magnetic tape)
⚠ Curator's note: This recording is unlike anything else in the archive. The frequency alone is anomalous — 1420.405 MHz is the hydrogen line, a frequency universally reserved for radio astronomy. No known intelligence agency is documented as having used this frequency for agent communications. The signal structure also departs from every known UVB-76 format. I have no explanation for this recording. I'm publishing it because I received it anonymously with a note saying it had been "suppressed for 58 years" and I believe strange things deserve to be heard.

► Full recording page with spectrogram analysis tool →

► Recent Archive Additions
DateStationFrequencyDurationNotes
14.10.1961 UVB-76 variant 1420.405 MHz 0:47 ⚠ Anomalous
06.08.1977 The Lincolnshire Poacher 11.545 MHz 18:40 MI6 / GCHQ format
12.03.1969 M8a (Soviet lady) 9.040 MHz 4:22 Standard 5-fig groups
29.11.1982 Cherry Ripe 14.920 MHz 8:15 Australian origin
03.07.1973 E5 (Czech lady) 6.995 MHz 11:04 OTP format confirmed

View full archive (412 recordings) →