The first known OK 2-way CW QSO at 535 THz (within the range of 461 - 788 THz) on December 31, 2016, 22:15z, over a distance of 90 kilometres, from JN89AO to JO80KF (SOTA SP/SW-001) between OK2BWB and my non licensed friend.
TX: Cree LED, total luminous flux 250 lm, apex angle 40°, 660 cd
RX: Naked eye, R-S: 33 (limited by air turbulence), binoculars 8x30: R-S 57.
Binoculars “RX LNA gain”: approx. 15 dB, given by: sqrt(2)*{30/7}^2
Vincent T Ciaramella, Message of Fire: An examination of the distances between the signal fires lit to announce the fall of Troy and determining if the relay system could work as found in the play “Agamemnon” by Aeschylus
The distance is what makes this so remarkable – I wouldn’t have guessed it possible without a much brighter light source or a collimated source (laser). Thanks for sharing this!
How does one record this activation in the SOTA database?
It’s not an amateur radio band; the frequency is above the scope of the ITU.
There was an interesting piece in one of the mags (Radcom I think) a year or two ago about lightwave, but modulation was involved - which I don’t think applies to the activity described above. In any case - modulation or not - lightwave is not part of the amateur bands.
Tom is right that it can’t be logged, non-amateur bands etc. but that doesn’t mean this kind of communications cannot be incorporated into SOTA in the future.
If added, one would expect at least one stage of electronics in the Receiver for it to count as an “amateur” contact, which is the basic requirement used for the VK7 experiments. “Visual reception” should not be acceptable…
So if you used the zoom on a digital camera that would be OK? Doesn’t make sense to me. Let’s turn it around: if you are against the use of eyes, would this invalidate the use of a morse code reader on the HF bands? Or reading FT8 signals or seeing SSTV images on the monitor screen? I think you are straining after artificial distinctions. To me the crucial point is that SOTA is an amateur radio award scheme, requiring that contacts are made between licensed radio amateurs in accord with the terms of their licenses. This is what the GR says. Nanowaves require no licence at present, the operators as yet need not be hams, so this activity can’t be part of SOTA. If the situation changes, as well it might when high powered light sources are involved, then this can be reviewed, but at present it is a fascinating sideshow.
Some of the members of the club I belong to have used lightweight, both red and ir. One used to hold the UK record for ir distance. Can’t remember how far exactly, 122km comes to mind though.
