Polish 11

Operating agency Unknown
Enigma family III
Country Poland

Polish (icon)

Operational detail pages
Active modes E11, S11a, F03, P03
Inactive modes G10, S26, S11, G11, M03, F11

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, S11aF03, and P03.

It is unconfirmed which agency runs this family of numbers stations. However, historically, it ran in parallel to and separately from the Swedish Rhapsody family of numbers stations, operated by the Polish UOP (Office for State Protection). As such, the Polish intelligence agencies AW and ABW, born in 2002 from the split of the UOP, can be considered as unlikely candidates for this separate Polish 11 operator. Rather, archive documents[1] as well as open records about suspected transmitter sites point to Polish military intelligence: Służba Wywiadu Wojskowego (Military Intelligence Service) and its predecessors.


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.

This agency has experienced a massive growth in activity during the mid 2010s, although the G11 and M03 modes have been retired since February 2014 and February 2016 respectively.

In the late 2000s, a digital counterpart to the analog voice and Morse stations appeared: F11. It wasn't operated as a different, independent station. Instead, it sent 10-15 minutes before the analog transmissions, sending the same traffic. Not all analog schedules had an F11 counterpart. After a long period of decline (going down from 17 active schedules in late 2014 to just 2 by mid 2018), its last schedule disappeared in December 2018.

Since at least early 2014, this operator has been experimenting with a more advanced modem, featuring a series of PSK (P03) and FSK (F03) waveforms sharing a common protocol. Unlike F11, its relationship with the analog modes is unclear. Many different variations of that modem have been on the air, but few have been adopted on multiple schedules.

Binding characteristics

  • All schedules, regardless of mode, use sets of up to three different frequencies depending on month: from November to February, from May to August, and one for the remaining months.
  • All frequencies the broadcasts are made on come from a restricted list shared by all modes.
  • Analog stations follow the same identical format.
  • By mistake, E11 broadcasts have occasionally used the S11a voice samples, and vice versa.
  • Digital schedules always have two transmissions five minutes apart.
  • Digital FSK modes use a repeating 16-bit word as the intro, while the PSK modes use a 4-bit word.
  • On October 12th, 2018, E11 transmissions happening concurrently to P03b transmissions, on other frequencies, were also leaked through crosstalk in P03b (see spectrogram).


This operator appears to use a single transmission center near Warsaw. Archive documents, open records such as calls for tender, precise TDoA multilateration results and field investigations indicate that this site is most probably the one located in Chotomów[2] at 52°25'46"N 20°52'53"E, and owned by the Służba Wywiadu Wojskowego. Additionally, in case of thunderstorms in this area, scheduled broadcasts are omitted.

Test/training transmissions

Analog broadcasts have an ID reserved for the purposes of testing and/or training: 121. It is heard only in unscheduled broadcasts at various times. The frequencies are typically low enough to be received within Poland itself. Sometimes these broadcasts are made at the same time and frequency for several days in a row.

Operation quirks

This operator is among the most professional on the number station scene, rarely making mistakes. Mistakes have included broadcasting on the previous schedule's frequency, using a wrong language on analog broadcasts, forgetting to open the sound channel (late start, normal finish time), and re-sending the previous month's message.

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.

Since October 2015, the analog broadcasts of this operator feature a 400-2900 Hz bandpass filter, slightly distorting all voice samples.

From June 2018 to December 2018, the analog formats E11 and S11a frequently lacked the operational words "Attention" and "Vnimanie", leading to lack of distinction between the different broadcast sections.

National Holidays in Poland