A natural follow up to watching the solar cycle progress, like we did with yesterday's post, is to ask what can we do if the ionosphere just won't cooperate?
This assumes you want to contact other people or places via ham radio, for some piece of wallpaper or other. I mean, obviously, if you're stuck in a broken down car in the middle of nowhere, you want some sort of phone or high bandwidth connection.
An answer that's easy to overlook and can work very well on VHF is meteor scatter. Back in April of '24, I put up a post about it, called "When Hobbies Converge or What The Heck is Meteor Scatter?"
Back in the 1950s, hams discovered that the trail created in the upper atmosphere by meteors burning up acted like a radio reflector, as if the ionosphere was enhanced. The effect is most beneficial to VHF stations which typically don't have regular, predictable ionospheric propagation. In the early days, this was done with Morse code, or CW as the hams typically call it (CW for Continuous Wave). Now that we're firmly in the age of computer assisted modulation modes, most people trying to bounce signals off the meteor trails are using a computer assisted mode. The most popular appears to be MSK144 (.pdf alert).
MSK stands for minimum shift keying, a form of continuous-phase frequency-shift keying (FSK) with shift equal to half the baud rate. MSK144 uses message frames of 144 bits and modulation at tone frequencies 1000 and 2000 Hz to transmit channel symbols at keying rate of 2000 baud. The resulting audio waveform can be viewed as a form of offset quadrature phase-shift keying (OQPSK) with individual pulses shaped like the first half-period of a sine wave.
Contacts made via meteor trails in other modes sometimes happen without either end of the contact knowing the connection was caused by a meteor and without using MSK144. Generally, though, your chances of success are better during the named meteor showers that get talked about regularly on sites like Space.com, as well as sites aimed more at amateur astronomers. While the number of meteors per hour varies widely between showers, there's generally one named shower per month, and there's some "sporadic meteor", also called a pebble or something, burning up in the atmosphere even on days when no "shower" is predicted. You'll have more luck looking for contacts in MSK144 mode on the frequencies hams have been using.
That's why I'm bringing this subject up now. One of the biggest regular annular showers has been ramping up, the Perseid shower, which will (purely coincidentally) peak overnight on Aug. 12-13 under the dark skies of the new moon. It so happens the 12th is the day of the solar eclipse that will be seen to reach totality from a few small areas in east Greenland, western Iceland and northern Spain, so the people who experience totality of the solar eclipse may be treated to a meteor trail or two.
While sporadic meteors can provide short duration openings, long messages can take excruciatingly long times to send. Meteor scatter also tends to be shorter distances. While multiple hop sporadic E can enable contacts across the US, meteor scatter tends to be more like 1000 miles or less. Occasionally, 1500 miles can happen. That cross-USA kind of multiple hop sporadic E seems to happen less often than meteor scatter, too.
Still, there have been a handful of grid squares in the SE US that I've worked by meteor scatter easier than waiting for other openings. There's such a thing as the other station being too close, too.
Perseid meteors streak over Lucerne, Switzerland, during the 2018 shower's peak. The photo was taken with an Olympus E-M1 Mark II camera in Live Composite mode. Scene exposure of 2 seconds; the Perseids exposure was about 30 minutes long. Orest Shvadchak
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