[NLRS] Use of Light in VHF Contests

[Zack Widup]

I honestly don't know why the rulemakers didn't want us using flashlights.
Maybe it seemed "un-amateur-radiolike" to them.

On lower frequencies, we're using a lot of electronics between us and the
signal. Antennas, transmitters and receivers; if it's weak-signal QSO's the
equipment has to be capable of a certain amount of accuracy and stability or
it doesn't happen. If you tell me you're going to be on 10368.100 and you're
really on 10368.297, I doubt I'm going to tune that far up to try and find
you.

At light frequencies, I'd say we really couldn't care less about bandwidth.
It's optical. Who are we going to interfere with? The flashing "Vacancy"
sign at a motel? Even an LED source can be processed with lenses so that it
is only visible over a quarter mile or so at the other end if the other end
is 10 miles away. Maybe even better. I haven't experimented with this yet.

I'm not in VHF contests just for the points, as a few people evidently are.
I'd rather use something more sophisticated than pushing buttons on a
flashlight to send Morse code. Maybe it's the techie in me that wants
something more exotic. But I don't see that lasers would be necessary for
optical QSO's. Evidently a few others don't, either, or the VUAC wouldn't be
reviewing the rule.

73, Zack W9SZ

On Tue, Dec 1, 2009 at 5:39 PM, Scott <acepilot at bloomer.net> wrote:

>
>
> Zack Widup wrote:
>
>> I don't recall exactly why the rule was spelled out the way it was but I
>> know for one thing it was an attempt to discourage people from flashing
>> Morse code with flashlights or high-power incandescent beams and calling
>> that "QSO's."
>>
>
> Well, why wouldn't it be a QSO?  Information was exchanged in both
> directions :)
>
>
> I don't recall how prevalent LED's were at the time. I know
>> there were laser diodes available in the early 70's but they were very
>> expensive. Other laser sources have been around for a much longer time.
>> Even
>> I had a small HeNe laser in 1969. I recall it was only $50 brand new.
>>
>> I'm not sure what exactly SHOULD be permissible for light sources in
>> contests. Obviously we still don't want people using flashlights, so the
>> part of the rule about at least one stage of electronic detection should
>> stand.
>>
>
> Oh, I see what you mean about flashlight QSOs, however, if something like a
> photocell was used to detect the light and turn on a buzzer or audio
> generator of some sort, I'd be OK with that personally.
>
>
> LED's would be the optimum light source IMO, and there would be more
>> optimum frequencies for use through the atmosphere than the red part of
>> the
>> spectrum.
>>
>> But I'm sure someone could come up with a method of modulationg, say, a
>> carbon arc. This would be an intense light source but would be
>> broadbanded.
>>
>>
>
> Heck, you're up in the TeraHertz...what's a few hundred GHz of bandwidth?
>  Plus, it's pretty much line of sight, so QRM should be fairly minimal
> (unless you live in a big city with lots of light pollution from other
> sources)...
>
> If we eliminate coherence as a requirement, how could a rule be worded to
>> limit the bandwidth of the emissions? Or would it have to spell out lasers
>> and LED's ONLY as a light source?
>>
>> These are tough questions I haven't figured out yet.
>>
>> 73, Zack W9SZ
>>
>> On Tue, Dec 1, 2009 at 8:58 AM, David Palm <thepalmhq at gmail.com> wrote:
>>
>>
>>
>>> T
>>>
>>
>
>