|Operational detail pages|
|Active stations||E17z, S06s|
This operator is unidentified and of uncertain origin. It runs E17z and S06s, which seem to have obvious origins in the Russian E17, E06 and S06 stations. However their formats are slightly different, E17z and S06s featuring pauses between the five 0 of the outro. With time they also received different voices.
Painfully compelling divergences reside not in the format itself, but in the contents: this operator uses very short messages, usually only between 5 and 8 groups. They are not encrypted using one-time pads, but more probably use a codebook, as pieces of identical group sequences are often observed multiple times in different transmissions. This operator also follows clearly different scheduling habits. Thus, and despite some habitual confusion from reporters, S06s operations really have nothing to do with S06.
According to this recording, this operator also has a German voice available, although it was never reported in an intentional transmission or as a normally operating station.
Direction-finding efforts have pointed to two separate transmitter sites in Northwest Ukraine: one in Lviv and one in Rivne. Observations of the Sunday 0630z/0640z S06s schedule using frequencies of 22 MHz and 20 MHz, given its particular propagation with a long skip zone, seem to indicate that a receiver located in Lutsk picks up the ground wave of this signal: this would be consistent with the nearby above locations in the same area.
Moreover, the presumed site in Lviv was formerly used by Radio Ukraine International, which would be public infrastructure and could point to a governmental origin.
On October 31st, 2016, operator chatter was leaked on the air 10 minutes before and throughout a scheduled S06s transmission: the chatter referred to regular transmitter warmup and setup procedures of this operator. It also revealed the operators using the Ukrainian language among themselves, as a supporting piece of evidence for the origin of this station.
Known test frequencies are 5140, 5454, 6280, 7635, 8180 and 10240 kHz, for E17z, using ID 274. These tests have been seen to simulate advanced transmission failure scenarios, going as far as fallback to live operators.