In this post, we'll go back more than 30 years to the years 1988 to 1990 which was around the time of the peak of solar cycle 22. In an issue of RadCom (journal of the RSGB) back in 1988, it carried this interesting news item...
"Graham Rogers, VK6RO, (Western Australia) has been granted an experimental licence by the Department of Communications to transmit on the spot frequencies 35.810 MHz and 4l.750 MHz for the purpose of propagation checks, particularly to ascertain the MUF (Maximum Usable Frequency) between 30 and 50MHz during the coming peak of Cycle 22.
FM will be transmitted, probably using a six element log- periodic Yagi covering 30 to 54MHz. with an cirp of about 83waits. Proposed callsign is VK6R. Graham will look on 28885 and 28385kHz for stations to stand by for his spot frequency transmissions. He is currently looking for a suitable transmitter."
It's worth remembering that this was a time when most people didn't have the Internet or even email. To let people know of any upcoming activity or experiments, you had to hope that people actually read about it in some amateur radio magazine.
Results... I asked Graham, VK6RO about this experiment and he said that he had managed to get a loan of a commercial low-band VHF FM radio for the tests. As for the tests, he did manage to get a report from a radio amateur in Japan on 35.810 MHz that was pre-arranged. The distance for the North-South path was in the region of 7000-8000 kms.
Graham reports that the biggest problem was the lack of activity on 28.885 MHz even though it was supposed to have been the 50-MHz liaison and crossband frequency at the time. Again, remember that there were no DX-clusters at this time.
Another problem that Graham notes was that most radios weren't able to receive between 30 MHz and 50 MHz back then.
Comment... While the tests met with limited success, the 35 MHz and 41 MHz signals would most likely have been heard in Europe near the peak of the sunspot cycle. The problem as already noted was that most radio amateurs probably weren't even aware of the tests at the time.
It's interesting though that the licensing authority in Australia at the time was willing to grant a temporary license for these frequencies. Could it happen again for say 40 MHz?
Maybe in the 40 MHz ISM band from 40.660 MHz to 40.700 MHz?
Would other licensing authorities around the world be willing to grant similar temporary licenses for the upcoming solar cycle 25?
Link...
1) For more information on the 40 MHz band, see a list of previous posts on this page on the blog... https://ei7gl.blogspot.com/p/40-mhz.html
