|Operational detail pages|
|Active stations||E11, S11a, F11, F03, P03|
|Inactive stations||G10, S26, S11, G11, M03|
This operator, who is believed to be a Polish intelligence agency, is one of the major actors in the field of numbers stations on shortwave. It currently runs many active schedules of E11, S11a, F11, P03, and F03.
In the early days, this operator ran a first (known) generation of numbers stations: G10 and S26. They both used the same voice format featuring musical call-ups. In the late 1970s, these stations ceased to transmit and were replaced by a new generation of stations, with an updated, similar but slightly different format, dropping the musical call-ups: voice stations in different languages E11, G11 and S11, and the morse station M03. In 1994, S11, which used voice samples in Polish, was replaced by a version using Russian instead, which eventually received the designator S11a.
These stations being used for a lower and decreasing number of schedules, G11 has ceased activity since 2014, and M03 since 2016. However overall, the activity and number of schedules operated by this agency follow a steady increasing trend.
Around 2009-2010, a digital counterpart to the analog voice and morse stations was introduced: F11. It is not operated as a different, independent station. Instead, it sends 10-15 minutes before the analog transmissions, sending the same traffic. Not all analog schedules have had an F11 counterpart. It is currently believed to operate as a legacy mode, having reduced its number of schedules from 17 at the end of 2014 to only 3 by the end of 2017. Schedules that used it were either stripped of their F11 counterparts, or shut down completely.
Early 2014 saw the appearance of a newer group of digital modes: P03. It operates standalone, without analog counterparts, is based on PSK and uses a more complex, binary protocol, which is not a direct translation of the analog format.
Schedules using P03 were steadily created until late 2016, when a group of FSK counterpart modes to P03 began operation: F03. Currently, all new digital schedules of this family use modes from this group.
This operator used the Windows XP OS as of 2014, as evidenced by leaked shutdown sounds after the last transmission of the day during that summer. Sometimes, two identical transmissions are sent at the same time on the same frequency, but usually the operators correct this quickly.
This operator is believed to use one TX site, located in the Warsaw area. This can be evidenced by:
- signal triangulation using direction finding equipment
- receivers in the Warsaw area picking up the ground wave
- several instances of scheduled transmissions being omitted during thunderstorms over Warsaw
- Warsaw being the capital of Poland and the most likely location for operations of a governmental agency
See also this blog post.