I am currently receiving a station in the Chinese language on 21550.00 Khz varying in strength between -76 dBm and -88 dBm (s7-s9) while my propagation widget is telling me 160 meters is fair and everything above that non-existent. 

     There are some deep fades and very bad selective fading that occasionally renders the signal unintelligible even when the signal is strong. There are some quite strong signals above 17 Mhz.  Given that it’s almost midnight local time this is somewhat unusual, especially given the relatively weak solar cycle.

     There is another station receivable on 21690.00 Khz but it is -90 dBm or less in strength and although I can tell there is a male voice, I can only hear it during peaks and there is too much noise to even discern the language.

     I scanned higher and found nothing and in ten minutes time 21690.00 Khz is no longer receivable, not even detectable.  The station on 21550.00 Khz is also gone.  Nothing above 19Mhz is receivable now.  There is a very strange periodically recurring signal between 18990 Khz and 19001 Khz that is almost like they’re trying to create an image in a spectrograph.  Check it out.  Tell me that isn’t weird.  It repeats about every 30 seconds or so.

     This is one mysterious weird signal.  Now 17,985 is the lowest frequency I can receive any voice transmissions on.  The propagation has changed dramatically in half an hour.  Time for me to call it a night.