It would be great to see more research into this area.

It isn't insurmountable, but it keeps most people from going faster. Perhaps 73wpm represents a natural speed barrier. Very few people ever develop proficiency beyond 75wpm. It is hard to imagine that this is just a coincidence that Morse code begins to take on a different sound at this speed! I'm far from alone in noting that Morse code takes on more of a pulsing sound at 50+wpm.Īt 73wpm, both the length of a dot and dash fall below 50ms - the dot is 16.4ms while the dash is 49.2ms. The average of these two numbers is 48ms. Research shows that as IOIs shorten to 50ms, human perception begins to shift from perceiving a beat/rhythm to pitch.Īt 50wpm, a dot is 24ms, and the dash is 72ms long. The faster the rhythm, the shorter the IOI.

In music, the inter-onset interval (IOI) is the interval between onsets of stimuli, or more specifically, the time between the perceived beginning of one note and the next one. However, this video may provide some insight. It just sounds different, and I can't explain it. Yet still higher, at 70wpm, I notice something distinctly odd that makes Morse code incredibly difficult to copy. In my experience, Morse code loses its signature tone as the speed reaches 50wpm or more, which can make it initially difficult to learn to copy. Music and Morse code share an underlying rhythm, and our internal clock governs our perception of that rhythm. I stumbled across a thought-provoking 11-minute video - What is the fastest music humanly possible? - that may have exciting implications on how we perceive Morse code at high speeds. To learn more about this fascinating topic, please take a look at Tom William's ( WA1MBA) Rain Scatter, SHF and EHF paper. Under ideal circumstances, 700km direct line-of-sight paths are possible.

The larger the angle between stations and the higher the thunderstorm, the longer the potential communication path becomes. And it just so happens that resonance occurs because raindrops are approximately 1/10 the wavelength of a 10GHz signal, which has a wavelength of 3cm. This is possible because scattering occurs more strongly as the particle size increases or the wavelength gets shorter. The 10GHz band lends itself to rain scatter and enables communication over hundreds of miles. The received signal was at 10.3681 GHz, and the remote station was 650km away, line of sight. But that is only the IF (Intermediate Frequency). Take a listen to this short video below, courtesy of Pete ( N0OY). Morse code with no tone?!? Under certain conditions, such as in a thunderstorm, a 10GHz signal will become so scattered that it sounds like pulses of white noise.

Cw programs for ham radio