[Laser] Lasers vs LEDs & ARRL contests

[GeoffK]

> By certain bandwidth I mean any light that most of it's output is confined 
> to a narrow spectrum.  I guess this would apply to most any solid state 
> light emitting device.
> Dex
>
I beg to differ: white-light sources, by definition, are broad spectrum, 
with  many wavelengths across the visible spectrum - perhaps even a 
continuous spectrum. Many Luxeons are white-light output, and so are 
broad-spectrum/ non-coherent. There ARE 'single' color Luxeons (and other 
LEDs) and I've never really understood why some of the most narrow-spectrum 
units are not allowed (as long as suitable 'narrow spectrum' language can be 
found).
Modulation - I've always like simple OOK (on/off keying) which is CW; you 
can't really do that with any source that requires higher voltage, e.g. a 
gas tube like a HeNe, although it is easy with most solid-state sources like 
laser diodes. There is nothing in the rules that requires a particular form 
of modulation; just as long as the required info is communicated any mod 
form is okay.
Geoff WA2GFP