[Laser] Re: Lasers vs LEDs & ARRL contests

[Clint Turner]

FWIW, I submitted a log entry for the 2007 10 GHz and up contest that 
was for a contact using a high-power LED that was accepted:  Some of the 
details may be found on page 80 of the March, 2008 QST.

Practically speaking, I have also worked the same 107+ mile path path 
using lasers, but the results were notably worse:  When working a 173+ 
mile path, the laser didn't work where the LED did...

73,

Clint
KA7OEI

> Hello to all Laser/light enthusiast.   
>
> As some of you may  know, I am the ARRL's Dakota Division VHF/UHF Contest 
> Committee (VUAC)  representative.  I am seeking your comments.  One of the items 
> that  has been under discussion by your VUAC is the ARRL General VHF Contest 
> rule 1.12  that states "1.12. 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."  This rule requires that the contact be made by licensed 
> amateurs  and that the detection requires at least one stage of electronics, that 
> much  seems fairly clear despite whether you agree or disagree with that part 
> of the  rule.   What is less clear is the requirement that the source use  
> "coherent radiation" and "(for example, laser)".  How coherent is coherent  ?
>
> What I would like your comments on is this.
>
> 1.   Given  this rule as it is now, does it include or exclude the use of 
> narrow band  LEDs like the Luxor.  I am no optics expert but it seems to me that 
> some of  these newer power LEDs are very close in coherence to really poor  
> lasers.   Does the current rule have enough latitude to include narrow  band LED 
> emitters ?
>
> 2.  IF we could rewrite the rule, what should  the rule say ?  Do we want to 
> be much more specific and tighten the rule so  it states "Laser only", or do 
> we want to open the rule up to specifically allow  the use of newer 
> technologies like power LEDs ?    In either case  what should the rule say ?
>
> It seems that on the one hand we don't want to allow a blinking white light  
> bulb, but if not that where is the line ?   
>
> Again, your  comments and perspective are most welcomed.
>
> 73, Jon
> W0ZQ
> Dakota  VUAC Rep
>   
>