History

S11a began in 1994, replacing S11, which transmitted in Polish. It became known for very little actual traffic, only sending null messages for years. This only changed in mid-2000s.

Since September 2002, S11a's audio comes from a PC. The old transmissions had better voice clarity than now.

S11a on December 3rd, 2001, before digitization. Recording courtesy of Numbers & Oddities.

Further information about the broadcast location. (Blog in Polish)

In 2006 - 2009, a variant S11b existed, which included the group "77777" as the first, second, last but one, and the last group of the messages.

Notable increase in activity of S11a was during September and October 2007, with daily messages of large amounts of groups.

Prior to June 1st, 2008, the null messages and message intros were 5 minutes and 20 seconds long, rather than the current 3 minutes and 20 seconds.

Up until mid-2013, E11 was frequently, but not always, observed with audio of bad quality, with distortions and/or background buzzing.

Distorted S11a transmission. Recorded on December 25th, 2011.

From April to August 2014, S11a was notably frequently observed with Windows XP shutdown sounds following the last schedule of the day, but not always.