1966 Spanish Numbers Station recording with synopsis by Don Hibschweiler

Many thanks to the Numbers Station Research and Information Center who have kindly allowed us to share their published article about a 1966 Spanish numbers station recording made by Don Hibschweiller. Many thanks to Mr. Hibschweiller for kindly allowing us to share his home recording here with the SRAA community.


(Source: Numbers Station Research and Information Center)

Spanish Language Numbers Station from 1966

The most active period of numbers stations monitoring began in 1980s as in efforts by “Havana Moon” or William (Bill) Thomas Godbey, Simon Mason and writers and editors of the “Monitoring Times” journal. Our site has studied numbers stations monitoring in 1980s. The great activity of numbers stations DX and monitoring lead to creation of online based groups like Enigma and Numbers and Oddities in early 1990s. However, number stations did not appear in 1980s, they been around since at least 1914. In their oldest simple form they started as Morse code transmissions, then live voice readings and finally automated voice transmissions, not stopping there yet as digital mode transmissions also hides numbers groups within.

The period before 1980s,1950s and 1960s were very active in terms of espionage. Many declassified documents tell us about CIA and SIS operations in Baltic States, Soviet Union and Eastern Europe and elsewhere using Morse code messages. Then there is a case of Operation SOLO of FBI infiltration in the American Communist Party and Soviet secret service, where numbers transmissions from the Soviet Union were involved.

Numbers stations were in the air and there were people listening to them. So this brings to the subject of this article: a authentic tape recording of several transmissions of Spanish language Five Digit numbers station recorded in 1966.

The recording was made by Don Hibschweiler, who is currently a morning radio host on 90.1 WFYI Public Radio.

As Don describes “the broadcasts were daily at 1700 EST on 6.805 Mhz. The recording was made on July 20, 1966 at my listening post in West Central Indiana. There are Spanish numbers in groups of five.  He always slowed down during the last set of numbers and then says something like, “Toonigh, toonigh”. I also heard one broadcast where the announcer made a mistake.  The broadcast was repeated later with the same mistake and a weaker signal.  I thought this meant the second broadcast was a recording of the first or both were recorded ahead of time.  Also, the difference in signal strength may indicate the use of a directional antenna and/or a different transmitter power.”.

What we have here is a recording of supposedly male voice Spanish language numbers station. The technical issues and specifics of the broadcasts may point to Cuba. Cubans in 1980s to early 2010s used voiced five figure stations with characteristic“Atencion” at the start of the broadcast. This is was known as V02 and V02a before moving on to hybrid digital and voice station HM01  This station however has no such prefixes. It could be old predecessor to Antencion station. CIA was caught using four figure numbers station in Spanish language, so CIA involvement  also cannot be ruled out.

Mr Don Hibschweiler came across this station after reading an article on “Electronics Illustrated” 1966 May issue.

The article is called “How to eavesdrop on real spies” featured real use of numbers stations and radio signal announcements as of case of Bay of Pigs invasion and the Rudolf Abel the Russian spy. It also featured some of the frequencies used by the numbers stations back then and the time of broadcast. Thanks to this journal Don was able to tune into this Spanish language number station.


The article points to various other numbers stations used in 1966. The German language station peculiarly plays “The March of the River Kwai” and classical music piece by Strauss as its interval signal. Such station has not been heard and any recording of such would be welcomed. 

In the 1960s the first automatic voice machines were developed. In the decade they spread also to Eastern Block. Automated voice creation improved numbers stations as the errors made during live reading were common. Cuba also eventually started using automatic voice transmissions, but this 1966 recording still indicates live or pre-recorded broadcast. 

This recorded Spanish language numbers station as for now stands unidentified until new documents pointing to it are found. This is one of the oldest recording of a number station publicly available and stands as important radio history source.

Many thanks to Numbers Station Research and Information Center and Don Hibschweiller for allowing us to republish this article and share this excellent recording.

"The Buzzer" (UVB-76) numbers station: May 13, 2018


Many thanks to SRAA contributor, Pedro Calhau, who submits the following short recording of "The Buzzer" (UVB-76) numbers station. Pedroo included the following details:

Date of recording: 5/13/2018

Starting time: 19:25 UTC

Frequency: 4625 kHz

Receiver location: The Netherlands

Mode: AM

Notes: This was recorded using the U Twente WebSDR

Numbers station HM01...and Ana Montes

Downloads-001Wednesday morning, I suppose I had number stations on the brain.  It was no surprise, as I had just watched The Numbers Station the previous night.  Nonetheless, I experienced a rather strange coincidence:  I was reading an intriguing article about Ana Montes, “one of the most damaging spies in U.S. history,” when my shortwave radio--parked on 5,855 kHz--suddenly began to fire out an eerie series of numbers and data bursts from the Cuban numbers station, HM01.  It was, unquestionably, the perfect accompaniment to the words I was reading. A reader sent Montes' story--written by Jim Popkin for The Washington Post Magazine--which made for fascinating reading. And as I read the account of Ana Montes' rise in the ranks of the DIA, while simultaneously becoming one of Cuba's most important spies, I remembered that it was actually Montes' case that reader Dirk Rijmenants' referred to in his paper, and that we posted earlier this year.

A "cheat sheet" provided by Cuban intelligence that Ana Montes used to help her encrypt and decrypt messages to and from her handlers. (Source: FBI)

Popkin's account of Ana Montes' life, character, promotions within the Defense and Intelligence Agency, and the sequence of events that led to her FBI investigation and imprisonment, are the stuff of spy novels. And of course, he  mentions numbers stations:

[Montes'] tradecraft was classic. In Havana, agents with the Cuban intelligence service taught Montes how to slip packages to agents innocuously, how to communicate safely in code and how to disappear if needed.[...]

Montes got most of her orders the same way spies have since the Cold War: through numeric messages transmitted anonymously over shortwave radio. She would tune a Sony radio to AM frequency 7887 kHz, then wait for the “numbers station” broadcast to begin. A female voice would cut through the otherworldly static, declaring, “Atención! Atención!” then spew out 150 numbers into the night. “Tres-cero-uno-cero-siete, dos-cuatro-seis-dos-cuatro,” the voice would drone. Montes would key the digits into her computer, and a Cuban-installed decryption program would convert the numbers into Spanish-language text.[...]

On a side note, as Rijmenants points out, using a computer to decipher a numbers station was both unnecessary and risky.

The story continues:

Ana Montes

[...]On May 25, 2001, [an FBI team] slipped inside Apartment 20. Montes was out of town with Corneretto [her boyfriend], and the FBI searched her closets and laundry bins, paged through shelves of neatly stacked books and photographed personal papers. They spotted a cardboard box in the bedroom and carefully opened it. Inside was a Sony shortwave radio. Good start, Lapp thought. Next, techs found a Toshiba laptop. They copied the hard drive, shut down the computer and were gone.[...]The documents, which Montes had tried to delete, included instructions on how to translate numbers-station broadcasts and other Spy 101 tips.[...][...]Later that day, an FBI evidence team scoured Montes’s apartment for hours. Hidden in the lining of a notebook they found the handwritten cipher Montes used to encrypt and decrypt messages, scribbled shortwave radio frequencies and the address of a museum in Puerto Vallarta, Mexico, where she was meant to run in an emergency. The crib sheets were written on water-soluble disappearing paper.[...]

The story Popkin recounts, though, paints the picture of a very complex operative. One who, until discovered, was very successful at her craft.  She pulled the wool over the eyes of the DIA and spied for the Cuban government for many years.

The story is complex, and Popkins' account somehow maneuvers through the twists and turns.

If you want to experience what I did--if a little less coincidentally--click here to read Popkin's full article, and meanwhile play this recording I made of the Cuban numbers station HM01, below:

Note that the year Montes listened to the Cuban numbers station on 7,887 kHz, it only contained numbers--unlike the recording here of HM01 (Hybrid Mode 01) which contains both voice and RDFT data bursts (which you can also decode, but not necessarily decipher).

This recording of the Cuban numbers station HM01 was recorded on April 24, 2013, at 10:00 UTC on 5,855 kHz in AM. Click here to download the recording as an MP3.

Again, click here to read Jim Popkin's full story of Ana Montes on The Washington Post Magazine website.

David Goren's numbers station installation audio

DG-Performance-ShortwaveTwo months ago, I posted that David Goren, talented radio producer and shortwave radio artist, created a Numbers Station installation in the Secret Wars exhibition at the Proteus Gowanus gallery in Brooklyn, NY. David has recently published the audio that accompanies his installation.

Take note that this is not a radio documentary--rather, it's an expansion of his original piece, and part of his sound installation at Proteus Gowanus.  Enjoy:

Numbers Stations: The English Man came back

Two weeks ago this Friday, I caught and recorded the numbers station often referred to as the English Man. He was found in the pirate radio watering hole (of 6,925-6,990 kHz) on 6,949 kHz. After sifting through more spectrum recordings taken the following evening by the Microtelecom Perseus, I realized that I caught him once again at the exact same time and frequency. I have his full transmission in the recording below.

Note: The English Man was broadcast in AM, but I had to dig the signal out of the noise. I used a tuning technique I referred to last year in a post--click here for more info.

Finding the "English Man" numbers station while scanning for pirates

While listening for pirate radio stations last night, I recorded a numbers station. I found it on 6,949 kHz at 1:30 UTC, 26 May 2012. It was broadcast in USB for almost exactly ten minutes. The ID was sent for a full four minutes of that time. I have a full recording below. With a quick check on SpyNumbers.com, I'm pretty sure this is a station called, the "English Man."

If you're not familiar with numbers stations, check out this previous post where Shortwaveology author, David Goren, explores numbers stations.

If you have trouble listening to the embedded player below, simply click here to listen to the mp3 file.