Polish 11

Operating agency Unknown

Enigma family III
Country Poland

Polish (icon)

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.

It is uncertain 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.


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.

The activity and number of schedules operated by this agency follow a steady increasing trend, although the G11 and M03 modes have been retired since February 2014 and February 2016 respectively.

Evolution of Polish 11 schedule statistics over the years

Between 2008 and 2010, a digital counterpart to the analog voice and Morse stations appeared: 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 currently appears to operate as a legacy mode, having reduced its number of schedules from 17 at the end of 2014 to only 2 by the middle of 2018. Analog schedules that used it were either stripped of their F11 counterparts, or shut down completely.

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, it operates seemingly independently of the analog stations. It appears to be constantly evolving: for the first 2 years of operation, new schedules were mainly using the P03 modes; the focus has since shifted over to F03. Additionally, there are schedules that shuffle through different modem waveforms depending on the season.

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).

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.

In October 2015, this operator introduced a low gain 400-2900 Hz bandpass filter on its analog broadcasts, slightly distorting all voice samples.

Since June 2018, a number of broadcasts of the analog formats E11 and S11a have lacked the operational words "Attention" and "Vnimanie" respectively, leading to lack of distinction between the different broadcast sections.


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, and Time Difference of Arrival multilateration (see example results below)
  • 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

TDoA multilateration of Polish 11 F03c transmission

See also this blog post relating to locating Polish 11 transmissions.

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