[Laser] Coherent Source - back on my soap box

[GeoffK]

Enough, already, youngsters ;>)
Those of us who were around back in the stone age of light-comms would 
possibly remember that there was at least one multi-op group (LONG since 
defunct!) that cut corners ... so, contacts above 300 GC. by flashing 
flashlights and visual reception were actually tried. The  League correctly, 
at the time, set up the Rule to require high-tech transmitter (e.g. laser) 
and high-tech receptor (i.e. at least one stage of electronic detection) to 
prevent the flashlight brigade from adding lots of Qs and sections (not 
grids back then). Some of us acquired HeNe tubes with appropriate PS and 
shutter mechanisms to 'modulate' the beam, lots of optics and 
photomultiplier tubes, and actually did Lx DX.
The available components have changed, but the Rule lingers on!
Geoff WA2GFP (still VHF+ contesting after 50+ years)

>I have never figured out why the requirement for contest QSO's is "coherent
> source." The rules also require that the source have one stage of 
> electronic
> detection - no sendimg Morse code by flashing the source on and off and
> copying it by eye. But you're right; outside of contests and for just 
> having
> fun you could use regular LED's.