|Name||D marker, Fazan-37|
near Saint Petersburg, Russia
"The D Marker" is a Russian military commandment network serving the Western Military District. It broadcasts on 5292 kHz around the clock.
While no other traffic is being sent, the station emits its signature channel marker, the sound of which resembles the Morse code letter "D". The traffic consists mainly of "Monolith" format messages addressed to Фазан-37 (Fazan-37).
This network had operated without a channel marker since as early as November 2011. The channel marker appeared on February 11, 2015; its first iteration had a different sound from today, and has proven to be very unstable at times. On June 5, 2017, the frequency was changed to 3240 kHz. On October 3, 2018, it was noticed that the D marker had started being receivable on 6480 kHz, a harmonic of 3240 kHz; this harmonic disappeared on November 5. On November 29, 2019, the station returned to its original frequency, 5292 kHz. In or after October 2020, the channel marker went off the air, permanently, and hasn't been heard since.