[NLRS] Use of Light in VHF Contests

[Clare Jarvis]

As a practical matter how many qso's could you do like this?  Just apply the grid cirling rules and rule all light as being in the 
same band.

WHat is the range of a flashlight? I would guess about 4 miles from high point to high point.


Clare K0ny



On Tuesday 01 December 2009 10:49:32 Mike KBØozn wrote:
> Hi all,
> I hope I don't sound too naive about all of this having not used this
> mode for any qso's as of yet, but it sounds like the rules on a low
> level are set up so that one is not allowed to use a plain old light
> source, like a flashlight for instance, to simply point it at the fellow
> you are trying to make a contact with and simply switch it on and off in
> a cw fashion to make the contact.
> But instead, one is required to use the light source like one would a
> radio.
> At the time these rules were made I would guess that lasers were  more
> or less the obvious choice for a light source.  These days, there are
> many choices for solid state light emitting devices, LED's, Luxeons
> (name brand bright LED), and lasers to mention some common ones.  I
> wouldn't eliminate gas laser tubes either, nor other light emitting
> technology for that matter.
> Personally I don't see any problem with using any of these safely to
> make the contact, again, as long as there is at least one stage of
> electronic detection.
> I've read about using cloud scatter for instance and that sounds pretty
> interesting, but I would guess that it wouldn't be even remotely
> coherent at that point even if it started out that way.
>
> In short I would agree that whatever we do it should encourage
> experimentation done safely, not stifle it.  To that end, I think the
> rules should be as open as they can be.
>
> As I reread this it does occur to me that one might simply modulate,
> perhaps with a switch (low speed) or a laptop (high speed) a flashlight
> (perhaps an LED one) and use a simple photo diode at the receive end
> tied into a sonalert, (low speed by ear decoding, aka cw), or laptop,
> (high speed decoding)
> I'm not sure if I would like this (the low speed part at least), but I'm
> not sure how it could be precluded either since one could easily do this
> with a laser and thus have coherent light, as well.
> Of course these are both digital modes and we could eliminate them by
> specifying no digital modes, but that would be pretty limiting these
> days and so I wouldn't be in favor of saying that.
>
> Well, that's my 2¢ for now.
>
> Mike
> KB0ozn
>
> David Palm wrote:
> > Those were some very interesting comments, Jon.  One question I have:
> > what is the rationale for specifying a "coherent" light source at all? 
> > We certainly don't specify that our radio sources must be coherent--far
> > from it.  So why should there be some difference as we get to this high
> > end of
>
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-- 
Mr. Clare Jarvis
President, Jarvis Computer Software
PO Box 1264
Winona, MN 5598707264

(507) 454-2575