E05 Cynthia – CIA Numbers Station

Early reports of E05 can be traced to the 1970’s. E05 was one of the English language number stations maintained by the CIA’s network, thus E05 earning the nickname “CynthIA”. The voice employed was very professional in its work, having an obvious American accent.  E05 fell silent in October of 2003.

Transmission schedules at E05’s height transmitted every day, in USB mode and a very strong signal sometimes more powerful than the AM broadcasts around it. At the end of E05’s existence over 100 regular frequencies were logged for it, being relayed from various countries allied with the US. When transmissions began a distinctive background noise was heard behind the voice machine due to high traffic. The noise itself could be described as the sound of rushing air.

Shown Above: Photo of Warrenton Station C (Remington Station) which was utilized by the CIA Office of Communications to transmit E05 and other CIA numbers stations. Credit: fas.org

Callup Recording Sample

Another form of this numbers station was identified as E14. E14 is a ‘control’ station, only sending call ups with no messages; possibly as a way to distract jamming efforts. E05 was another station that had issues with being the victim of intense jamming attempts.  These jammings were suspected to be from Russian or Iraqi warble jammers. Eventually the jamming was less prevalent, maybe because they had something more important to cover.  Or the party jamming and the CIA came upon an agreement to stop jamming each other so much.

E05 and the other language counting number stations could be heard from a very wide range.  It was transmitted as low as 3190 kHz and as high as 27095 kHz.

The jammers would appear at either side of the transmission making it impossible to copy. Sometimes the call up would send clearly, only to be drowned out once the message arrived. On longer transmission the jammers would sometimes go off, its operators making sure E05 was still there before resuming. These became less frequent in the mid 1990’s and E05 had a mostly clear broadcast for the remainder of its life.

Two transmissions were also sent at the same time.  It was another effort to fight the jamming, and to ensure there was at least one clean signal.

E05 Cynthia Number Stations Transmitter Locations

E05 could have been sent from many of the CIA’s transmitter sites.  Two Cynthia transmitter sites have been confirmed to be at Warrenton, VA, USA and Frankfurt, Germany.  Other transmitter sites for this station and the rest of the CIA’s number stations network could possibly be in Guam, Japan, Australia, Diego Garcia. Also South Africa, Europe; England Barford St John, Oxfordshire; Germany Frankfurt area; Spain; Portugal; Greece, Tatoi and Nea Makri near Marathon; Turkey; Morocco.

Message Format

E05 transmissions begin on the hour.  The transmission begins with a 3 figure ID that is repeated three times, then is followed by counting “1234567890.” This repeats for 10 minutes. After the 10 minutes of repeating callup, 10x one second bursts of 1000 Hz tones are sent and she say’s ‘count’ follow by a two or three digit id. The 2nd ID is spoken again with the group count.

Then the message is spoken with a distinct pause after the third number. After the message is sent she says “Repeat” followed by the count again. Then the message is repeated and ends with “End.”

797 797 797 1234567890 1000 Hz tone Count 88, Count 88 050-42 520-64 930-28 658-60 … Repeat Count 88, Count 88 050-42 520-64 930-28 658-60 … End
3-digit ID 3x Repeats 10x Group Count
5-digit single groups.  Pauses after 3rd number Group count
Message repeats.  5-digit single groups.  Pauses after 3rd number Outro
Repeats for up to 10 minutes

Message Sample – Without the 3 Digit Callup

E05 Station Summary

Nickname: Cynthia or The Counting Station
Activity: Inactive Since Oct 2003
Emission Mode: USB + Carrier
Voice Summary: Automated woman’s voice with an American accent
Country of Origin: Warrenton, VA, USA and Frankfurt, Germany; Possibly others in the EU and around the world.
Family Relatives: G05, V05, E14, E21(#), V14 (# May not actually be part of the network)
Station Family: Family 2 “CIA/NSA”


Cynthia number stations recordings via industrial
Simon Mason Karoo “E5 Counting Station” (Archived)
Enigma 2000 Newsletter 19 (November 2003) Page 3
ENIGMA Newsletter 4 Page 13
FAS Intelligence Resource Program – Warrenton Station C (Archived)