By Maris Goldmanis
The Numbers Stations are not new radio phenomena; they have been spotted on the radio waves since World War I and became most prominent during the Cold War. Yet the first organized group specializing to monitor and log number stations was founded on 1993. It was original Enigma active from 1993 to 2013 They work was greatly inspired by the Cold War era numbers stations. Yet less information is publicly available about number stations monitoring before the foundation of Enigma. That gap is now filled with the release of the Monitoring Times Magazine – a popular radio hobby magazine published from 1982 to 2013. The site American Radio History provides us with their issues from 1983 to 1989. Monitoring Magazine covered a wide spectrum of radio hobby interests – ham radio, shortwave radio station listening and logging, the newest radio technology and… numbers stations. The authors of the journal were also interested in these strange signals, made few interesting discoveries and published their findings. What’s more memorable that from 1984 to 1986 on semi regular basis a special section “Les Numeros” by Havana Moon about numbers stations was published within the journal. Havana Moon or William (Bill) Thomas Godbey, KB2OOR was one of the first numbers stations monitors who published his findings on journals like Monitoring Times and the Popular Communications. He lived for many years in the West Palm Beach area, moving later to Briarcliff Manor, Ossining, NY. His pen name was based on a 1983 music album by Carlos Santana, hinting that at least some of the numbers stations he investigated were transmitting from Cuba. He is the author of book the “Los Numeros” and “Uno, Dos, Quatro – A Guide to the Numbers Stations”, published by Tiare Publications. His editorials on the Monitoring Times shows a great insight into Cold War era numbers stations. This article will take a insight into Monitoring Times publications mentioning numbers stations from 1983 to 1989.
On November-December issue the prime attention is devoted the Cuban “5 digit Spanish circuit” a early name to the V02 station. The station was reported to be active on the 3090/4100 kHz on the hour with repeat at 15 past the hour on 3090/4040 kHz. Other strange signals were heard on 7540 and 8805 kHz – a YL in English with alpha characters in groups of five. Also 8127 kHz in English at 0100z alpha numeric characters in heavy Spanish accent. Also notable is report from West Germany about German language station on 2030z on August 31 Thought to be a native speaking because “finif” was used for “fünf” (5) as with German radio ops. The recitation was terminated with a chime sounding at 2051z. From the description the station reported was no other than the gongs and chimes G03 the famous East German STASI numbers station. Also, it was reported that the Soviets change their codes and ciphers on 24 hour basis, sometimes on 12h basis. The longer a code or cipher is used the more vulnerable it becomes.
The February issue begins with feature article about the US Air force HF communications mainly the Emergency Action Messages. As today they used general voice call “MAINSAIL”. Any station hearing this call responded and provided the requested service. Usual service was direction finding, phone patch for official communications usually over AUTOVON (Department of the Defense Automatic Voice Network System), or to request Clear/Secure radio teletype, configuration used is
MIL STD 188C, 100 wpm 850 Hz FSK, 2.0 kHz center frequency (space 2425 hz mark 1575Hz). The journal published all known frequencies and schedules of the EAM broadcasts from their base locations. Many of the bases are still used today; however the frequencies differ from now. Meanwhile Havana Moon was short on interceptions on this issue however noted Spanish five digit transmission on 6229 kHz at 0500z on 25/11/83.
In March issue Havana Moon reported that many listeners became concerned over 5-digit Spanish transmissions and sent complaints to the Federal Communications Council (FCC). One of the first such FCC response to the 1976 request was such: “”…We have determined that the signals you described are emanating from outside the United States. Consequently, this administration has no jurisdiction over the operation. Regretfully, we have no definitive information to give you.” Such similar worded responses were sent to other listeners over the years. On November 1984 Havana Moon reported that a National Security Agency (NSA) agent says that they monitor the 5-digit transmissions, but won’t comment anything else.
The April issue featured a numbers stations story on the top list. An article by Bob Grove tells about recent finds by the radio listeners such as the German number broadcasts are traced to Nauen city in the Eastern Germany, the five-digit Spanish and English stations are incoming from Cuba. Suspicions arouse around “kilo-papa-alpha two” transmissions that possible comes from Yugoslavian embassy in Ottawa Canada. With no confirmation from Canadians. But, then the interesting part begins: according to Monitoring Times (MT) listeners the 4 digit English/Spanish transmissions on 9074 kHz and 1153 kHz are actually a US origin. FCC had monitored them and their bearings show that without a doubt the station signal comes from Washington DC area. To determine who is actually using them one MT reader took great time and traveled long miles. He ended up in eastern Virginia near the enclosed site with a barbed wire. He had Kenwood R-100 installed in his old car with a whip antenna. He tuned to 9074 kHz and heard a faint carrier noise indicating that either the transmitter is tuned up or is too far away. Suddenly a paralyzing “Uno,dos,tres…” count begun showing that the site surrounded by dipoles and log periodic arrays is the source of these 4 digit broadcasts. He then tuned off frequency to find a powerful CW station. Carefully retuning his receiver dial he found a Morse signal tape booming on 6925.5, 10637,12022, and on 15540 with the call sign KKN50 officially assigned to the US State Department, but suspected to be used by Central Intelligence Agency (CIA). The place where the signals came was Remington, Virginia just few miles north of the Culpepper route 651. The sign on the entry gate said that this is “Warrenton Training Center, NCS station C US army”. Where the station was A, B and what does the NCS stand for? 12 miles east of Culpepper he found another similar station with dipole antennas labeled as “Station D, Warrenton training center” A long periodic antenna broadcasted KKN50 CW broadcast on 1825 kHz
MT made contacts with US Army Public Information office and received no useful information other than this site is top secret and all information about it are classified. However, then MT found that NCS according James Bamford author of the “Puzzle Palace: Inside the National Security Agency, America’s most secret intelligence organization” the NCS is none other than the National Communications System. So it was a US number station, but questions remained was it was a training station for deciphers at the CIA or NSA or it has something to do with 5-digit stations coming from Cuba Maybe they are coming from US controlled Guantanamo Bay? As usual FCC gave no answers and questioned the accuracy of the statements made by the MT. However, Havana Moon labeled this as the “BIGGEST story to hit the communications world in over two decades!” Havana Moon also received confirmation from a “non-FCC source” that the 5-digit Spanish transmissions are from Cuba and accepted by the Cuban Spanish government and some of the similar stations. The source had connections with many connections with the US government was considered reliable. It was also reported that 4-digit Spanish and occasionally English reading voice on 4307, 6840 and 9074 was the same as the “Spanish Numbers YL” 4670, 5810, 9074, 11532 and 14968 kHz. It was also noted that the 4-digit Spanish numbers transmission site was at Warrington was home to the Army Cryptography School on 1942. Possibly the school still worked but under different name. Later however it was reported by a MT reader that NCS is actually National Cryptographic School. The Warrenton site also called Hill Farms was used according to reader as the NSA communications intercept site. Later it was confirmed that NCS was actually a National Communications System that was introduced on 1962 and disbanded on 2012.
On May MT reader reported that he’s been listening to the Cuban number stations broadcasts since 1985 on 5985 kHz and has made schedule: 0900z 7 days wk-practice message? Three long groups of five digit numbers spotted on 1000z Thursdays, through Sunday mornings short messages 20-30 digit groups. 1030z repeat of the 1000z message. Similar pattern used by V02a in 2012-2013.
On June another numbers station was found this time in Czech language simulcasting on 3767 kHz 4030 kHz the location of the transmission was thought to be Vratislavice, Czechslovakia.
On July the CIA number station again made the MT headlines. A past example of use of the 4-digit 9074 kHz frequency was found in Nicaragua. A local anti-American Marxist newspaper “Soberania” reported that on 1982 Nicaraguan Marlene Moncanda was recruited by CIA to assassinate Nicaraguan foreign minister Miguel D’Escoto. She worked in the Nicaraguan embassy in Tegucigalpa, Honduras and was trained by CIA of how to operate shortwave radio and received instructions from messages on 9074 kHz and 14421 kHz on 11pm from CIA at Langley,VA. When she was arrested the Nicaraguan Counter Intelligence demonstrated evidence- two wooden idols about 20 cm. tall, one of which could be opened to reveal a tube where the keys to decipher the radio messages she was to receiver by radio were found. The spy messages would be written in four digit groups that make up the content of the radio messages. Code books showed that she received 4 digit messages. Another agent Carlos Rodolfo Icaza Espinoza was also alleged to receive CIA messages on 14156 kHz. The radio both were using was Sony ICF-600w If the information in the Nicaraguan magazine was correct then it showed the connection with the 4-digit stations at the Warrenton Site and showed how the numbers stations are used in practice.
As the numbers stations became popular a book called How to tune to the secret shortwave broadcasts” by Harry Helm for 7,99 $ was advertised on MT. One of the first of its kind. The Havana Moon looked back on 1961 event the “Hollow Nickel” case or the case of Rudolf Abel who was highest ranking Soviet spy ever captured spying in US. He received instructions from KGB via 5 digit groups on 17 MHz, 14 MHz and 6 MHz frequencies from CW station with a 3 element numeric ID. He was detected because he unintentionally gave one of his special nickels to the paper boy as a change; inside the “Hollow nickel” there was coded message. It took many years for FBI to decipher the message in the Hollow Nickel for it was found on 1953 and after a series of events in 1961 their find the culprit Rudolf Abel.
On August strange transmission of five musical notes followed by groups in unknown language was reported on 0530z on 4030 kHz. However, some MT reader sent letters of protests that the journal is too focused on the number stations and gives very less information about activity VHF/UHF spectrum that is also interest of many of the MT readers. However, the Havana Moon continued his regular columns looking to find the source of the 5-digit Spanish transmissions on 3090/4040 kHz, whom he thought might be also from US. The Warrington 4-digit numbers made a huge sensation among the media causing for people to search for government secret radio sites all around the country. It was also reported that the notorious 4-digit sites at Warrenton were restricted to the soviet diplomats and journalists. On December article suggested that some of these 4 and 5 digit transmissions comes from Norfolk Naval base and are used for encrypted communications between the land and sea and the transmission site is located at Driver,Virginia. Meanwhile Havana Moon discovered the disappearance of the five digit transmissions on Sunday from 0000z to 05000z. Meanwhile Spanish 5-digits were found on daytime as reported by listeners in Florida. On November one listener reported that the Spanish 5-digit female voice transmission was 13640 kHz was playing backwards. Unfortunately he did not record this strange event.
While gathering usual information on the 4 and 5 digit stations, Havana Moon also received interesting notes about German language station. On 11617 kHz “unknown language German sounding female” with 5 digit groups preceded by “flute sounding instrument and voice in unknown languange”. It could have been the G18-8 Note Rising and Falling station. But, even more intriguing and what Havana Moon called “Bizzare” was a “Gypsy like song with violins and whistler and then Termina! Termina!” The weird broadcast was received on 6824 khz that Havana Moon attributed to the Basque separatists. Because of the strange language and music. However as Termina means end in Romanian this station came from communist Romania and was later called V1 Romanian Skylark.
January Havana Moon column featured a long reported, but forgotten “GBZ2” station on 6270 kHz with the “British accent” repeating GBZ2. It was first heard on November 3 1983. After repeating a noise described as “data bursts” in AM mode. The New England based monitor mentioned that after the increase of hostilities in the Middle East there was great increase of the spy number broadcasts. The frequencies 3820 kHz and 4670 kHz were reported to be very active at night. Both the reporter and Havana Moon speculate that these YL type stations with peculiar accent might be used by Israeli Mossad. Indeed the Mossad number stations were known to use NATO phonetics with strange accents.
On March MT received letter from Major David N Stone, executive officer, Office of the manager, of the National Communications’ System who read the MT article about the NCS affiliated number station in Warrenton. He explained that the NCS is “a confederation in which Federal Government departments and agencies participate with their telecommunications assets to provide essential communication services for the Federal Government under all conditions ranging from normal day -to -day situations to national emergencies and international crises, including nuclear attack.” The NCS is used by wide set of US government agencies including CIA. The officer wrote that NCS can be used by each of the government agency to satisfy their working needs. So MT speculated that the number station sent from army radio site can be used by CIA, Defense Department and NSA.
Meanwhile other listeners reported strange male Spanish voice number station on 5615 kHz about 0100z “with rather unevenly spaced 5-digit transmissions with less “mechanical” sounding voice than others stations heard. The signal was very strong in Florida. Meanwhile Havana Moon was puzzled by the strange phonetic alphabet stations appearing on 7445 kHz on 0215z and on 0245z received mostly in USB mode. While some DX clubs label them as “utility stations” the Havana Moon noticed that the “traffic frequency” 7540 khz becomes active five minutes after the cease of the 7445 kHz activity. The usual “traffic format” starts with JID in phonetics for many minutes, then “Message, Message”, then “Text, Text”, then message comes in phonetics, and concludes with “End of Message”. And the “Repeat” goes all around again. He also noticed that phonetic “November” is always spelled as “Novebeer”. What Havana Moon did not know back then, but what we now is this station was E10 used my Israeli Mossad with “Novembeer” as of its peculiarities. 
On May the MT again returned to the famous USAF EAM’s describing the meanings of the various code names used in the messages like “Skybird”, “Skyking” and so on. “Skybird” for instance meant “alert all bombers aloft”, Skyking meant “ATT Any SAC Sta” meaning attention to any Strategic Air Force station”. Ringmaster was call to the NORAD HQ, Raw Hide was codename for president Ronald Reagan, Timberwolf- Vice president George Bush, Cement Mixer- White House and so on. This leads to an interesting question does some of the codenames are still used and what is the codename for current president Obama and vice president Biden?
On June Havana Moon noted strange Spanish five digit station that was read live. Not only that, but before the numbers the female operator said word “Attencion” for three times, 472 as the identifier 40 group count, message and “Final”, “Final”. This might be one of the first test transmissions of the famous Cuban V02a Attencion station that continued to broadcast until 2012 when it turned into hybrid mode HM01. The transmission was on 3688 kHz at 0337z. Another find was the Czech language station in five digits that starts with five musical notes for three minutes then the numbers follow. What was peculiar that all five digit Spanish transmissions cease after the start of the Czech transmission. Another listener reported about the Bulgarian numbers station on 6676 kHz on 2300z.
On July the monitors of the Warrenton/Remington numbers station finally managed to make a list of frequencies used by it and its schedule (picture bellow) that was a result of a careful devoted work to the numbers stations monitoring. On August the usual Spanish five digit frequency 3090/4030 kHz was switched to 3090/5090 kHz. Meanwhile the new 4-digit transmissions showed up on 4310 kHz at 0430z.  Another interesting observation on that month was 12470 kHz on 2336z was AM tones “as someone was keying an electronic organ signal 40 over S9”. Havana Moon stated that it possibly could have been European embassy transmission. Was it some early variant of XPA or X06?
On October MT concluded a poll on the most monitored radio signals by the readers. Numbers stations gathered 6%, while leading was police 54%, aircraft 39% and broadcast 39%. Also the MT listened to the Russian ships on HF and made pronunciation table of the Russian numerals.  On November one concerned reader sent a long letter to MT voicing his concern over the numbers stations articles epically about the Warrenton sites. He stated that information published on these articles may help the US rivals like USSR and others to do harm on the US security. Reminding that “loose lips –sink ships” he demanded justification for publishing such “juicy story that you know might help to sink a ship”. The author of the letter wished to stay anonymous. MT responded that they are sorry that their articles about Warrenton offended the reader, but stated that they fail to see how these articles help to “sink a ship”. Hard to say who was the complainer – concerned patriotic citizen or a government representative trying to silence these publications.
On December someone noted a Russian numbers station on 6839,5 kHz. Not much was given besides that it was in Russian. Havana Moon made frequency and schedule list of the “phonetic stations”, “two letters phonetics in German and English”, “five digit German/English”, and “German five digits “with music box introduction”. The German numbers station with a “music scale” was attributed to the recent spy scandals in the Western Germany. The station was used by Eastern Germany.
The MT January issue was the last of the regular Havana Moon “Les Numeros” columns. With the phrase in French au pays des aveugles les borgnes ont rois (In the land of the blind the one -eyed are kings.) he said adios to his readers and contributors giving no explanation about the cease of his publications. He concluded his regular list with the list of the sites that according to him were the five digit Spanish number stations in state Florida. First site was northwest of the Miami, Florida the INS/BP and prison and VHF/HF antennas and 16 meter dish for FLSATCOM. Second; the US Army communications service detachment west of the New Dade county zoo. Site contained many HF and VHF antennas and encrypted RTTY on 149.000 MHz was sent regularly not far from there. Third site was the USGC COMSTA Miami at the north eastern corner of site one at the Florida Turnpike. Site with dozens of HF antennas including long periodic’s, rhombic’s, conical monopolies and 250 ft tower VHF/UHF unidirectional antennas. Site four was the US Navy Security Group, Card Road about four miles from the Florida city. In the multistory building, set inside two rings of approx 150 ft radio towers. As Havana Moon always stressed that he does not believe that all five digit Spanish numbers broadcasts come from Cuba.
On next issue first regrets that the “Los Numeros” has been removed from MT appeared on the readers mailing list for one reader the “Los Numeros” was the sole reason for subscribing the MT. Just to show how interesting were the numbers stations back then for listeners. On the final “Havana Moon” column interesting reports about 4 digit “Polish number station” and possible Mossad freq on 9260 kHz. Still without a doubt he laid more arguments that these 5-digit Spanish numbers are the US origin and other possible sites were the Ft. Launderdale and near the Palm Beach international airport. 
On next issue the MT advertized “Havana Moon” book “Los Numeros” and “Uno, Dos, Quatro – A Guide to the Numbers Stations” apparently after long years of numbers monitoring he finally was ready to assemble his observation in one book. On March “Havana Moon” returned with occasional non regular appearance. This time he again reported about “Polish numbers station” repeating “zero, dwa,jedna (the last pronunced as jedena)” This could be also Czech station as the number yeden (one) means the same. On June issue Havana Moon mentioned English live 5 digit transmission as well as other 5-digit Spanish numbers broadcasts. That was the last of the Havana Moon columns. In future MT issues the number stations were mentioned in the logs, the usual Polish/Czech stations, German stations and the Spanish 5-digits. In so the MT issues became less interesting.
Some of the notable mentions are on November issue the report about the FCC conference where they released the list of the jammer locations. As we know during the Cold War the soviet jammers were the most active. The jammer types were nicknamed “spark” a broadband electrical pulses to wipe out a wide spectrum of frequencies. “Sweeper” a strong carrier swept at audio rate back and forth across the targeted frequency sounding much like diesel engine. “Step tone”: a constant series of randomly selected tones (usually 3-bag pipe tones) repeated constantly at the target frequency. And the “noise” – simple white noise transmitted on the frequencies. In Soviet Union the listeners unable to listen to the western broadcasts called these jammers “saws” that sawed trough the broadcast. FCC also for the first time disclosed locations of some of the notorious “single-letter beacons” located in Soviet Union used by their navy. However, no comment was made about the number stations as they fall out of FCC responsibility.
On May issue the MT featured an excerpt from Havana Moon’s book proving that they still haven’t forgot about him. In fact they advertised his book almost on every issue. The book fragments introduced to various numbers stations, how to listen to them and about their origins. Much of the content was seen in the “Los Numeros” columns in 1984-1985 issues. On September Havana Moon appeared again on MT telling he was former member of the intelligence community and involved with the communications activities for most of life. He listed some “hot” frequencies on 3090, 3120,3130,3690, kHz some of them, but not all came from Havana, Cuba. The repeats for those were 4030,4445,4670,4780 kHz 30 past the hour. He also listed some FEMA frequencies that send number station like broadcasts. On November he returned again in the section called “Numbers Stuff”. One of his revelations was that bizarre “gypsy music station” actually comes from Romania. On December it was reviled that some of the phonetic stations are German probably Eastern German origin.
January issue featured interesting article about the Guatemalan rebels who use the number stations. It was suggested that number transmissions on 9996 kHz started by test count 0-9 in Spanish followed by the numbers of five digit groups. The men behind these stations were said to be Unidad Revolucionaria Nacional Guatemalteca (URNG) rebel group. the number of the next line of text. The last two or three minutes of this 20 or 30 minute transmission are sometimes given over to political talks and occasionally there are mentions of the names of military districts and \or rebel company numbers. The transmission, even more rarely, will end with identification for “La Voz de URNG”. Although these communications were mostly used on VHF sometimes they showed up on shortwave. Such rebel communications were also used by Radio Marti the anti-Kastro rebel radio station.
The May issue featured interview with author of the well known spy bestseller Puzzle Palace James Bramford. When asked about the number stations he said it’s obvious that these stations are for clandestine use. He recalled events mentioned in his books when spies were caught and in their trial it was mentioned that they received coded messages from shortwave radio. Such instance was Geoffrey Prime who was soviet spy within British GCHQ and was caught with old German shortwave receiver on which he listened to the Eastern German number stations. Prime then used one time pad to decipher them. It’s evident that other nations including US used such methods of spy control.
On June a new 4-digit Spanish number stations broadcast site was found in Florida. The site was located is 26 degrees, 56 minutes north and 80 degrees 5 minutes west, just to the south of Jupiter Inlet. From aerial photos a triangle of three circular HF antennas were found. It was disclosed how the site was located to be a site of the 4670 kHz broadcast. A microwave receiving antenna was also noted and transmissions in the 2 GHz range aimed at this antenna were monitored coming from a passive repeater to the south of Jupiter Inlet. These transmissions were eventually traced further south to their source atop the Federal Building in Miami, Florida. Transmissions on this microwave link appeared to be data that MT source says is then decoded at the numbers station site and synthesized into the voice transmissions for broadcast. The site was reportedly owned and leased by the federal government to the RCA Communications. It was also stated in the article that one disclosed CIA spy Mario Casagrande made interview to the Italian magazine “Europeo” who received CIA transmissions with the simulated females voice known as the Cynthia fro Langley. It began with ten minutes of identification, during which a series of three digit numbers was transmitted. If the middle digit was even, it meant that a message would follow. When there was no message the digit would be odd. To decipher the message, he had to subtract the numbers received by the radio from those written on the tiny pad. The results were numbers between 1 and 26, equaling the number of letters of the English alphabet. The number 1 corresponded to the letter “A “, 2 to “B” and so on. This system is absolutely unbreakable by anyone without the tiny pad, and every message is decipherable only by the pad of the agent to whom it is sent. In the case that the pad should fall into the hand of the enemy, it is possible to decipher messages for a limited period of time only. The content of these messages were requests for information or the operational orders. While his time in Cuba he received about 35 such messages every year.  On next issue some US army veteran send letter stating that Ft. Bragg US Army Special School is the place where people are trained to send and receive number stations. And also these stations were used during Vietnam war. 
On May issue the 4-digit number station site issue was again raised . Many utility shortwave listeners have heard the government run CW station KKN39 (listed by Enigma as M25) on 4956.5, 13387, and 17413.5 kHz. Although some have listed KKN39 as being located in Washington, D.C. (as KKN50 is at Remington, Virginia, 50 miles southwest of Washington), others have speculated that, based on propagation, KKN39 is in Florida. For instance on 1986 Havana Moon stated the one of the 4-digit sites was located at the Dada Zoo Park/Gold reserve drive, south west of the Coral Reef drive. MT author made successful fox hunt found the transmitter facility. It is about 1.5 miles south of US 41, SR 90, SW Eighth Street, Tamiami Trail on Krome Avenue, SR 997, SW 177th Street, old SR 27. (Most major Miami streets have several names causing confusion with different maps. In fact, the Dade County phone book map mistakenly refers to Krome Avenue as 977th Street.) This is seven miles northwest of the NCS /Richmond NAS site and about 15 miles west of downtown Miami. The sign says “Transmitter Facility, Regional Communications Activity, National Communications System, U.S. Army,” and KKN39 signal levels were 60 dB over S9 (full scale). No “numbers transmissions” were foundto originate from this facility. In fact, it is at a distance from Cuba that would make it a poor choice as an HF facility to hit Cuba — it is too close for any but the lower HF frequencies. 
On September Harry Helms published new book the Underground Frequency Guide listing all know active number stations frequencies on 1989. On November the strange Chinese language number station first noted on 1977 was indentified as the China Republic (Taiwan) run numbers station. Nicknamed “New Star” it was heard on 11430, 15388, 9725,8300 kHz. Later Enigma gave it V13 designation. On last publicly available issue on December 1986 one listener reported six digit number stations in El Salvador. It may have been run by one of the fighting sides in the El Salvador civil war.
Our story ends here. Although probably once more Monitoring Times issues becomes publicly available more information about early day numbers stations monitoring will be told. As we saw the numbers stations were interest for many shortwave listeners and Monitoring Times not only endorsed they researched them themselves. The discovery of the Warrenton 4-digit Spanish numbers broadcast site run by CIA made MT famous. The 4-digit Spanish station run by US government is forgotten part of the numbers stations history. But, no doubt the work of the William (Bill) Thomas Godbey the Havana Moon and other MT contributors were inspiration for Enigma, Numbers and Oddities and others numbers stations listening communities. Also for the people of the numbers-stations.com. We hope more MT articles from 90ies will available to public for this is one of the best sources about the numbers stations history.
- http://www.simonmason.karoo.net/page8.html http://www.americanradiohistory.com/Archive-Monitoring-TImes/Monitoring-Times-1985-01.pdf
- http://www.numbers-stations.com/E10 http://americanradiohistory.com/Archive-Monitoring-TImes/Monitoring-Times-1985-05.pdf