The Russian Buzzer, ENIGMA ID S28, on 4625 kHz, is currently in one of its extended breakdowns. They periodically happen and can cause a splash within certain communities when they do, certain doom porners really run with it. Since at least 0130 UTC this morning, 17 February, 2020, and as of the time of this posting, 1430 UTC, the Buzzer has not been sending its normal periodic buzzes, instead it has had a deep transmitter hum. Several times in that period the normal, or a relatively normal, interrupted buzz has returned for short periods, always to give way to the transmitter hum.
At about 1240 UTC I tuned to the signal to see if it was still malfunctioning. I happened to have caught one of the S28 messages the Buzzer periodically transmits. After the message it returned to the same broken transmitter hum.
https://www.youtube.com/watch?v=hmIYiQVjagUT!