Meyerton and Pyongyang on 3,320 kHz

3,320 kHz is occupied by transmitters in Meyerton, South Africa and Pyongyang, North Korea but at my location in grid square CN88 they are not heard at the same time because there is never a time when all three locations are even close to being in darkness. By the time each UT day begins, Meyerton has been in darkness for several hours. Not too long after that, the sun sets here, a darkness path exists and a tropical band opening is created. A couple of hours after that, the sun rises in South Africa and the signal is lost. A few hours later, while it's still night time here, the sun sets in North Korea and the signal from Pyongyang propagates well across the northern Pacific. Eventually the darkness path is lost when the sun rises here. This conveniently lets me compare two very different paths on the same frequency every UT day.

Starting in late March, I recorded 3,320 kHz for 10 consecutive days and then again for nine more days, but not quite consecutively.

The first 10 days are shown here...


Averaged together, they look like this...


The remaining nine days are shown here...


Averaged together, they look like this...

The 2019-03-19 curve terminates early because of a mistake I made with a circuit breaker in preparation for the arrival of an electrician.

During the period of these recordings I paid a lot of attention to the popular space weather indices but could not find any that correlated with the observed signal strengths. The second period had more varied signal strengths than the first but I could not even find any reason for that. The only trend I can even claim to see is that signals tend to be strongest during twilight at the receiving end of the path.