The mysterious signal known only by its initial content has been heard in numerous places throughout known space for at least the last 250 years, possibly longer. The signal is broadcast over a narrow subspace band and comes from an unknown origin. At first thought to be an anomaly in decoding algorithms that mistook naturally occurring subspace noise for a coherent signal, it has since been proved to be artificial. Though similar in occurrence to Echo Signal Alpha 1 Omega, the signal does not appear to be from a Subspace Deep Echo Array and its origins remain a mystery.
First Occurrence
The first verified occurrence of the signal was in year 2133. An early Warp 1 vessel exploring the edge of the Terran system recorded the signal clearly on their subspace communications system. It was a fluke that they even heard the signal, as the ship had been disabled by an extra-solar meteor shower after an accident in engineering disabled the main deflector dish. The vessel was forced to drop out of warp and conduct repairs. In attempting to call back to the Earth Space Agency (ESA) for technical assistance, they picked up the signal on one of the narrow side-band channels that was generally unused.
Signal Contents
Code 11271. Repeat. Code 11271. Tango Bravo Alpha Niner Zulu Seven. Confirm 11271. Tango Bravo Alpha Niner Zulu Seven. Confirm 11271.
The carrier signal begins 3.47 seconds prior to the start of the audio transmission and what follow never deviates outside of expected parameters of subspace noise in the region. Once the signal has finished a cycle, the carrier wave holds for 3.47 seconds exactly before the carrier ceases. The signal carries on a cycle for 2 hours repeating at regular intervals.
Studies and Origins
The signal does not appear to be localized to any particular area of space and has not yet been recorded appearing in the same region of space twice in a row. The mean time between occurrences is roughly 10-14 months, though there are extended periods where it is not recorded. In 2281 the starship USS Lexington happened to be doing a subspace interference survey within range of the signal and recorded a great deal of data about the signals parameters. On another occasion in 2309 the Klingon vessel the IDF K'Ta was on stealth maneuvers and was able to record vital information about the signal as well, believing it to be a covert human signal within Klingon space, they spent a considerable amount of resources to attempt to locate its source.
So far no attempt to trace the signal to its source has been successful. The closest was when the K'Ta found a signal vector but was unable to verify this vector to establish a distance and bearing.