Joe
>The digital modes qualify since the output medium is audible radio waves - not
>light - which is >being received/transmitted.
Wrong. "Radio waves" are not audible. Neither is light. They are both forms
of electromagnetic radiation. The ONLY difference is frequency.
Since you cannot audibly or visually detect radio, electronic detection is
required to convert RF to a form that can be interpreted by humans - audio, or
perhaps even light for the hearing impaired.
Electromagnetic radiation in the Terahertz range, otherwise known as light,
unlike RF, can be detected by one of the human senses (except for the visually
impaired).
Thus the requirement for a stage of electronic detection - it equalizes things.
>Same goes for television since the medium is inherently audible as well.
No, you can't hear the visual or aural portion of television either - unless
you have some sort of electronic detection to convert the RF to audio.
>Granted, the final communication is visual since I've never purposely tried to
>decipher these >modes by ear alone :)
It becomes visual through electronic detection and conversion to a visual form.
>
>My original thinking was the case for flashing signals with a polished mirror.
> While not >defined as radio, it is a valid form of communication - as are
>the smoke signals I mentioned >previously.
Thus the reason for the VUAC's proposal. Light reflected off a signal mirror,
or smoke signals, or candle flames, or flashlights, are not coherent radiation.
Laser is.
>A visible laser like emission shone across two mountain peaks at a blackboard
>can >only be >deciphered visually since there is no human audible component.
Yes, it can - but there is no electronic detection required. The rules
specifically state that at least one stage of electronic detection must be
used. Whether the output of the electronic detection stage is audible, or
visual, or tactile is irrelevant. The rules are still being adhered to.
Several have mentioned the use of LEDs in place of lasers. If the rules are
opened up to allow the use of non-coherent radiation of LEDs, then flashlights
and the other methods of visual communication mentioned will be within the
scope of the rules. They currently are not.
Anyone visually detecting terahertz radiation, coherent or non-coherent,
whether it is transmitted by flashlights, smoke signals, or lasers, is in
violation of the current rules.
73,
Bruce WW1M
>
>The audio provision seems to me a reasonable theorem, yet it's solely my own
>and unscientific. I am not trained in this subject, so my approach is from a
>layperson's perspective.
>
>Thanks for helping me exercise the gray matter :)
>
>
>
>________________________________
>From: George Sintchak/WA2VNV <wa2vnv@optonline.net>
>To: Joseph Nieves <n2tee73@yahoo.com>; vhfcontesting@contesting.com
>Sent: Mon, December 7, 2009 6:26:09 PM
>Subject: Re: [VHFcontesting] The meaning of coherence [was: [WSVHF] [VHF]
>VUACSeeks Input]
>
>Joe,
>
>You say "audible transmissions" - so no RTTY, WSJT or PSK31 would be
>allowed.... Is that what you mean?
>
>You also say "the human communication factor is always audible" so I guess
>you don't watch any TV or read (this) email on you computer monitor coming
>into your home over the fiber-optic cable - is that TV only "audible
>communication" ?
>
>
>
>----- Original Message -----
>
>From: "Joseph Nieves" <n2tee73@yahoo.com>
>To: <vhfcontesting@contesting.com>
>Sent: Sunday, December 06, 2009 3:24 PM
>Subject: [VHFcontesting] The meaning of coherence [was: [WSVHF] [VHF]
>VUACSeeks Input]
>
>
>All:
>
>Fiber-optics terminate at my home for Internet and phone service. While the
>transmission medium is light based when I pick up the phone receiver, the
>human communication factor is always audible. To eliminate smoke signals
>and garage door openers, how about just limiting QSOs to something like:
>
>"Electronic devices capable of emitting and receiving audible
>transmissions..."
>
>Still gets a bit sticky since my description above would technically make
>legal electronic drum sets :)
>
>In all seriousness, come up with a consensus on the spectrum's real world
>"high bar" for audible radio waves as opposed to light waves medium. When
>an enterprising ham breaks the "high bar" barrier, you move the contest goal
>post as well.
>
>Regards,
>
>Joe Nieves, N2TEE
>
>
>
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>
>
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