Many thanks to SRAA contributor, Manfred Reiff, who shares the following recording and notes:
I made this recording on (our) Sunday 30 October 1977 at 0841 to 0853 GMT (now: UTC) on 21570 kHz. It was one of my first recordings made with a newly bought GRUNDIG Satellit 600 Professional. I used both the built-in Telescope Antenna (144 centimeters in length) and a self-made outdoor antenna consisting of steel mast of 10 meters in height. On top of the mast my dad and I installed a copper pipe of nearly 5 meters in which we put a solid steel mast. In the gap my dad filled in liquid silicone to stabilize the system. We connected both metallic parts so it looked like a conductor. The antenna still exists although I moved to another location in 1987.
Please note that it is the original recording without editing it (reduce noise).
This recording was made on 30 October 1977, starting at 0841 GMT on 21,570 kHz: