There is a lot of long wave usage in Australia with NDBs from 200 Khz to about 450 Khz and VLF stations such as North West Cape operating on 22.7 Khz sending messages to U.S. submarines from Washington.
PROPAGATION OF LONG WAVE
Unlike short-wave with deep QSB LF signals tend to be steady over long distances even during night time, Because of more ground wave characteristic a 100 watt station would have about the same range as a 1000 watt medium wave broadcast station during the day.
In 1968 during a world trip I was starting to hear European long wave broadcast stations when I was halfway across the Atlantic ocean including the BBC on 200 Khz with a transistor portable radio at night.
At my Cousin's place in Surrey England again with a small transistor I could hear most of the European LW stations including Warsaw 1000 miles during the day with not much different signal strengths at night.
Long wave broadcasting 150 - 285 Khz is limited to region 1 [ Europe ] and Russia , Eastern Russian LW stations have been heard in Victoria at night with weak signals.
North West Cape near Exmouth Western Australia is an U.S naval communication station runs about a megawatt on 22.7 Khz sending messages to submarines.
VLF stations including OMEGA navigational
systems can be heard world wide day and night due the ground wave and ducting
between lower layers of the ionosphere and the Earth's surface.
AMATEUR RADIO AND LONG WAVE
Some countries have allocated portions of the low frequency spectrum to licensed Amateurs and other countries have allowed experimental stations conduct tests on LF.
In New Zealand Amateurs can use 160 to 190 Khz and propagation tests between ZL Hams and VK stations with permits are very common in the evenings Mode used is usually on CW since it is about the best mode to get through band noises with weak signals SSB has been used at times.
In the United States anyone can use LF on 1750 Metres using license free equipment but would not be really suitable for serious LF experiments since the power is limited to 1 watt and aerial not more than 50 ft long.
UK amateurs can use frequencies as low as 73 Khz and 136 Khz since the 160 - 190 Khz region is allocated for Long Wave broadcasting.
Here in Australia submissions are in motion between the WIA and the ACA to negotiate for a LF Amateur band.
LONG WAVE LINKS
The following links are provided to some of the most interesting WEBSITES.
73 Lionel VK3NM/VK6DC