This unidentified operator of Ukrainian origin runs primarily the S06s station, along with its lesser-used E17z English language variant. Despite the historical designators and similarities in format, these stations are not to be assimilated or confused with the Russian S06 or E17 stations of the Russian 6 operator.

On top of using different voices from S06 and E06, painfully compelling divergences reside not in the format itself, but in the contents: this operator uses very short messages, typically only 5 to 8 groups long. Pieces of identical group sequences are often observed throughout multiple different transmissions.^[1] Each schedule carries one message for the first 2 weeks of the month, and then another for the further 2 weeks. None of this behavior is exhibited by S06 and E06, despite S06s being often incorrectly reported as "S06".

As binding characteristics, in addition to these traffic patterns, and transmitter signatures, S06s and E17z voices were mixed together in at least this same pre-transmission warmup. According to the following recording made before a scheduled transmission on July 18, 2013, this operator also has a German voice available, although it has never been reported in an intentional transmission.

Almost all of this operator's voice activity goes through S06s: E17z is used only for a single weekly schedule, and training transmissions.

On August 1, 2019, nearly all S06s and E17z schedule IDs were changed, marking the first such event in the known history of this operator. The previous IDs have been in use since at least the late 1990s.

Since the night of February 24, 2022, when the large-scale military operations and invasion of Ukraine by Russia began, this operator has ceased all activity and transmissions on the air. The precise reason is unknown, as well as whether and when operations could or would resume in the future.

Location

The primary transmitter site is located north of Rivne, Ukraine. Apart from S06s/E17z, this site also carries digital activity using proprietary systems, both broadcast and point-to-point. One of the identified point-to-point link targets was the Ukrainian peacekeeping mission in the Democratic Republic of the Congo.

For a few days starting on October 31, 2016, operator chatter was regularly leaked on the air 10 minutes before and throughout scheduled S06s transmissions: the chatter referred to the routine transmitter warmup and setup procedures of this operator.^[2] It also revealed the operators using the Ukrainian language among themselves, as a supporting piece of evidence for the origin of this station.

Training transmissions

This operator holds training transmissions several times a year. They are made in English (E17z) on various frequencies including 10240, 8180, 8080, 7635, 6280, 5454, 5252, and 5140 kHz. The transmission ID is always "274."

These transmissions cover various failure scenarios, such as interruption during the intro or in the middle of a message. To accommodate them, the messages sent are usually several times longer than the standard 5 to 8 groups. The last resort scenario shown in these transmissions is fallback to a live operator, either male or female, who reads out the message just like the usual generated voice does.

Operation quirks

In addition to training transmissions, on October 7, 2021, a scheduled, production transmission of S06s was performed by a seemingly live operator instead of its automated voice, making it a rare deed in this automated numbers station era.

References

1. ENIGMA 2000 Newsletter #87 (March 2015), pp. 45-48 [accessed 22 September 2018]
2. Numbers & Oddities Newsletter #229 (October 2016), pp. 14 [accessed 16 July 2018]