[Laser] Coherent Source - back on my soap box

[Zack Widup]

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.

73, Zack W9SZ

On Tue, Nov 3, 2009 at 2:40 AM, Tim Toast <toasty256 at yahoo.com> wrote:

> hi James,
>
> To me it looks like the rule is meant for contesting credit only
> and doesn't apply to other activities.
> I propose that "coherent source" (eg laser) in this context be
> interpreted as: "any light source which has a bandwidth of 50nm
> or less". This should include most led's and lasers we are likely
> to be using. Light sources with larger than 50nm bandwidth could
> be considered "broadband" and put in some other "contest credit
> category". Since there may be some advantage to using greater
> bandwidths or diversity reception or other redundancy effects,
> i think broadband optical sources should not be outlawed in contests
> completely.
> Even without some special interpretation, i think both LEDs and
> Lasers are "coherent enough" though.
>
> -toast
>
>
>
>
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