[NLRS] Use of Light in VHF Contests

[Mitch Aanden kc0jfy]

In reality light is an electomagnetic entity.

The issue is where do you draw the line between radio waves and photons, 
It's a grey area.

I use plasma everday at work.  Should that be considered too?

My honest opinion is that lasers and any coherent/columated light should be 
in a class of it's own
and should be a seperate contest.

That's my 2 cents.

Mitch kc0jfy



----- Original Message ----- 
From: "Donn - WA2VOI/0" <wa2voi at mninter.net>
To: "Ray J" <Ray at w9ray.org>; <NLRS at mailman.qth.net>
Sent: Monday, November 30, 2009 23:25
Subject: Re: [NLRS] Use of Light in VHF Contests


>
>
> Unfortunately, there's a fair amount of ambiguity even in the definition 
> quoted:
> -what/which "fixed...  relationship?"
> -what/which "phase ?"
> -for how LONG a period of time ?
>
> These matter 'cause, for example, lasers have dispersion, or broadening, 
> of
> their spectrum.  How much dispersion are you willing to tolerate before 
> you no
> longer call the light "coherent ?"  That's the problem.  Similarly, how 
> about
> "monchromatic light," i.e., a single "color ?"  No argument that a 
> flashlight
> (or similar) does not qualify... "white" light is ALL COLORS, and 
> therefore
> cannot be coherent.
>
> This is an important question for a couple of reasons (that I can think 
> of,
> anyway):
> -some lasers can be dangerous (yes, even the ones that are $10 pointers)
> -lasers turn out to NOT be the best way to go for communications.  They 
> produce
> a beam that is too small (in diameter), such that atmospheric disturbances 
> can
> prevent the QSO... think QSB.
> -sources such as LUXEON(tm) LED sources are much cheaper, safer, and 
> better
> suited to communications than lasers (many, anyway).  (And no, not all 
> LEDs are
> laser sources.)  Many LEDs produce "monochromatic" light, but with HIGH
> dispersion.   Is it still "coherent ?"  Luxeons produce light that is 
> coherent
> with MUCH LESS dispersion. (Think of signals smeared by aurora vs. 
> non-auroral
> ones.)
>
> The poster, Jon, W0ZQ, did give contact info...
> "http://www.arrl.org/contests/vuac.html".  It turns out he is aVUAC
> representative, and the list gives his snail mail address.  His e-mail 
> address
> is in what you quoted.
>
> 73 Donn
> WA2VOI/0
>
> ----- Original Message ----- 
> From: "Ray J" <Ray at w9ray.org>
> To: <NLRS at mailman.qth.net>
> Sent: Monday, November 30, 2009 10:48 PM
> Subject: Re: [NLRS] Use of Light in VHF Contests
>
>
>>
>>
>> isnt the Dictionary meaning  pretty foolproof?
>>
>> coherent light-
>> "light in which the electromagnetic waves maintain a fixed and
>> predictable phase relationship with each other over a period of time."
>>
>> lasers should produce a coherent beam of light... a flashlight will not..
>>
>> w9Ray
>>
>>
>> too bad the arrl vuac representative list doesn't  give any contact 
>> info..
>>
>>
>> jcplatt1 at mmm.com wrote:
>>>
>>> Hello NLRS land.   The ARRL's VHF UHF Advisory Committee (VUAC) has been
>>> formally directed to review the adequacy of VHF Contest Rule 1.12 
>>> regarding
>>> Light contacts.
>>> PUBLIC STATEMENT>>>>>>>>>>>>>>
>>>
>>>
>>>    The ARRL VUAC has been directed to review VHF Contest  Rule 1.12 that
>>> states "Above 300 GHz, contacts are permitted for contest  credit only
>>> between licensed amateurs using coherent radiation on  transmission (for
>>> example, laser) and employing at least one stage of  electronic 
>>> detection
>>> on receive"  to determine if the rule should be  modified to make it
>>> clearer as to the meaning of coherence.  The VUAC  is interested in your
>>> opinion and any suggestions that you may have.   Please forward your
>>> comments to your Divisions VUAC representative.   Your Division VUAC
>>> representative is listed at  http://www.arrl.org/contests/vuac.html)
>>> end >>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>
>>>
>>>
>>> Please provide me, your Dakota Division VUAC representative, with any
>>> comments & suggestions that you may have on this subject.   If you are
>>> outside of the Dakota Division, I would ask that you send your input to
>>> your own VUAC representative - if you have any problems IDing your
>>> representative, or cannot contact them for some reason, drop me a note.
>>>
>>> 73, Jon
>>> W0ZQ
>>>
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