FBI Operation SOLO – Numbers Stations Revealed

by Māris Goldmanis on January 6th, 2015

5 – Figure numbers station message groups


During the Cold War it was a challenge for the intelligence agencies to get their top insider agents within the Soviet Union. For the CIA, the most successful insider story was the Soviet colonel Oleg Penkovsky. He reported vital Soviet military information that helped US to gain upper hand in the Cuban Missile Crisis. For the FBI, the “success story” was Operation SOLO. The story focused among certain individual “Morris Childs” born “Moishe Chilovsky” in Kyiv, Ukraine in 1902. He came to the US in 1911 and became a member of the US Communist Party (CPUSA) and worked as editor for the newspaper Daily Worker. He had fallen out with the party in 1948, and three years later he and his younger brother Jack were approached by the FBI. It was the very heart of the Cold War when the FBI was trying to gain information on the CPUSA and other pro-soviet organizations by getting insiders. It was called program TOPLEV. Jack Childs a naturally born hustler and bag man for the CPUSA underground financial operations took the offer and later convinced Morris who was a top member of the party.

Morris Childs gained great influence within the party and in 1957 was asked by his members to become an international emissary to establish and maintain relations with the Kremlin. This was a breakthrough for the FBI who for years tried to prove that CPUSA follows the directives from the Soviet Union. It was also possible to gain FBI insider within the Kremlin. The Kremlin fell for the bait and Morris Childs traveled to Soviet Union on April 24th, 1958. He met with the top communist party officials in Moscow and the leader of the communist China Mao Tse-Ung. He gained the Kremlins trust and was even invited to the communist partys 21st congress. For the next two decades he took fifty-two international flights where he met top communist party leaders around the world. His reports greatly served the US foreign policy when dealing with the Soviet leaders and gained the FBI and its legendary director J. Edgar Hoover great prominence above CIA.[2]

Morris Childs was awarded with the prestige Soviet Order of The Red Banner signifying how much Moscow respected him. His last flight to Moscow took place in 1977.  In 1982 he retired, ending the 13 year running Operation SOLO. Never before or since in the FBI’s history has it kept agents on a single case for such a protracted period. In 1987 he was awarded with the US Presidential Medal of Freedom. Morris Childs passed away in 1991. Twenty years later in 2011, the FBI released large quantities of the Operation SOLO declassified documents.  With some parts still crossed out, the documents present a great insight of this man’s work within the highest ranks of CPUSA and the Kremlin. Some of these documents also lead to evidence of use of coded numbers messages over the radio and teletype. Also some ciphered messages were delivered using drop-ins.

This document contains instructions of how to use the supplied  “Walky-talky radio and small tuner”. These required him to send three short test signals by “WT”. He had to connect his “WT” to the car antenna and make 3 test signals while driving. The small tuner was needed to tune his radio set. He had to switch the radio to the middle of the bands and bring it to the tuner as close as he can and get the highest volume possible on the radio set. Then make a mark on that place. The picture of the walky-talky in the document looks like an AGS WTR-903 AM Band & CB Transmitter Receiver.

The transmitter/receiver from the operation SOLO document. –
AGS WTR-903 AM Band & CB Transmitter Reciever which looks similar to the one in document

The image on the right shows an AGS WTR-903 AM Band & CB Transmitter Reciever which looks similar.

Another more interesting document dated July 28th, 1964 contains highly valuable confidential information for a “highly valuable informant NY 694-S* (possibly Morris Childs) who has been receiving communication transmitted to him by radio. Transmission was heard by an FBI radio station in Midland at the scheduled times and frequencies which the message “NR 974 GR 409” was sent. Below is the plain decoded text and the ciphered message. The message is genuine 5 figure group number station message that contains information about the members of CPUSA and other foreign communists of visiting Moscow and holding a conference. The other “monitor number 2” station  heard on all 2 contacts and with 5 group chipher shows further information on the communication between Moscow and CPSUSA on an arranging visit. The end of the picture also shows the drop in container.

SOLO Memorandum
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Other documents also show evidence of the numbers stations listening for operational purposes. Page 5 again mentions transmitting to informant NY-69-4* presumably Morris Childs that as mentioned above was sent on scheduled time and frequencies. However, no messages were transmitted. Presumably it was one of the common “zero zero zero” message. This document is dated December 9th, 1963.  Meanwhile this decoded message with cipher included contains the CPUSA reaction to 1964 US presidential elections.  Some ciphered messages showed  initial confusion caused by president John F. Kennedy’s assassination, that also advises him rush money (50 color prints repeat number 50 color prints) before the first of the year as the “emergency amount”.

This document contains the Soviet transmitted instructions to Childs that were heard by the FBI listening post in “Midland”.  The whole SOLO documents collections features many deciphered messages showing that use of number stations were integral part of Operation SOLO. These messages were transmitted by the soviet agents of the CPUSA to Childs as their own agent.  Childs then leaked the frequencies and ciphers to FBI, who monitored these transmissions and deciphered them. Most of these messages contained information about the daily work of the CPUSA and other pro-soviet activists, who wanted to keep secrecy from the FBI and CIA. As it was well known that both FBI and CIA almost manically tried to pursue and catch the communist spies during fifties and sixties and beyond.

One document of decoded message shows the frequencies used by these number stations. The message states that “Again your-radio signals of the 14th were unreadable. Therefore my walkie-talkie signal of the 15th, asking for a radio repeat. Three radio repeats have been requested during this period. In recent weeks radio signals were weakened fading, together with atmospheric and local interference. Based on past experience, successful radio results at this time of year should be possible if the frequency-range were increased to 12 megacycles through 15 megacycles, preferably in the 1 Hz megacycle range.. Request this frequency change be made as soon as possible using the same GMT as using now.”  Megacycle is equivalent to megahertz showing that the spies had the usual problems with the propagation we all sometimes face.

After some time another intercepted message states: This will acknowledge your radio schedule for May. New time two hours later with 12666, 13582 and 14413 respectively. The numbers above refer to radio frequencies. Regarding the later radio signals on April 25th and 28th, the conclusion is that best reception is obtained at the later time and on the higher frequency. In all radio signals the reception was much better than on the regular current schedule. This shows how the schedule change takes place. Also a reception report adds to use of the lower frequencies. “Reference to radio reception on Tuesday, November 16, 3R2,1115 GMT freq. 9347 radio fair, but heavy atmospheric and QRM disturbances. 1135 GMT, freq, 10345 much improved less atmospheric disturbances and QRM. 1155 GMT,freq. 11449  radio all signals perfect no atmospheric disturbances no QRM” – these signals are equal to the very best of the radios: in the past.

The technical details of sending these signals are described in this document containing FBI intercepted instructions.  From agent TALANOV to NY 69-4* the instruction describes of using the micro-transceiver. Its advised to not be in the hurry when he has 25-30 groups. He could also transmit 45-50 group message at such speed as in the test. Also the microphone  should been further from the sender when recording. So it was pre-recorded live voice message. The document is marked from 1965. The brand of the transmitter is mentioned on the 1964 document as “E.F Johnson personal 2-2way transmitter”.  Such company really existed and produced AM/CW consumer transmitters.   However, with no brand name mentioned we can only guess how micro was the “micro” transmitter on 1964. when first transistor radios appeared. Then the locations of micro-transceivers are named and to be used only once. For direct contacts with the spy rig center a walky-talky was used. The “Walky-Talky” radios as one mentioned here before also had its own schedules which were mentioned in the documents. Another document also notes that transmitter was installed in a car.

SOLO NY Schedule
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However, because of the frantic work of the double agent Morris Childs, these codes were exposed. Using double agents and insiders is one of the most possible ways to unlock the enemy codes, but also one of the riskiest. Oleg Penkovsky from the CIA was unfortunately caught and sentenced to death. Morris Childs was able to avoid detection and ended up as one of the most successful American spies.



1.)        http://vault.fbi.gov/solo
2.)        Weiner,Tim. (2012) Enemies: A History of the FBI. New York. Random House, p. 174-179.
3.)        http://www2.gwu.edu/~nsarchiv/NSAEBB/NSAEBB375/