I've regularly heard XSL on several frequencies between 8 and 9 MHz, but recently it seems that I'm picking it up more actively between 4 and 5 MHz. Is this just due to propagation changes?
As I was looking at the Youtube clip, I was curious--what's the tone that starts at about 0:40?
Also, what's the wide chirp that happens at around 0:43? It shows up as a yellow bar across the entire waterfall display. I hear that regularly, almost regardless of frequency or time of day up here in Alaska. I haven't identified a pattern with it, but every 10 minutes to 30 minutes I'll hear it.
Thanks for posting this Token!
The 4 MHz freqs of the slot machine are up all the time, in fact almost all of its frequencies are up almost all the time. So, if you are now hearing the 4 MHz freqs it is just propagation.
At 0:40 in the video I switch to a new frequency, in this case 6250 kHz. There is a BC station carrier at about 6250.4 kHz, mixed in with the Slot Machine signal, and that is probably the tone you are talking about. There is also general rise in the background noise level and that is caused by both the BC station and a Chinese OTHR (over the horizon radar) that sometimes covers the same frequency range.
The yellow bar you are talking about at 0:43 is an ionosonde, also called a chirpsounder. Yes, they do sweep on regular and generally published times and at specific rates. There are many all around the World. However, if you really want to you can plot time vs frequency and figure out which one (or ones) you are hearing at your specific location. They sweep a rather wide range, with some going from 1 to 40 MHz. Most generally only sweep say 2 or 3 MHz to 28'ish MHz.
Here is a shot of one sweeping from about 6600 kHz to about 28000 kHz, it was probably starting much lower down, say 2 or 3 MHz, but propagation was not showing it at my location until it got up to a little over 6 MHz. In this image you can also see that there are at least 4 ionosondes active at this particular time.
T!
