[VHFcontesting] The meaning of coherence [was: [WSVHF] [VHF] VUAC Seeks Input]

George Sintchak/WA2VNV wa2vnv at optonline.net
Fri Dec 4 16:28:39 PST 2009

My $.02 thoughts (coherent or not).

Laser or LED, coherent or not? Which mode gets the message completed for a 
valid contact? Does it really matter?  A non-coherent flashlight emitter 
aimed at an electronically amplified voice modulated reflective speaker cone 
which can be seem from a 1km distance thru a telescope with a 
photomultiplier amplifier and eye piece photo diode detector connected 
to....... Please read on....

Most of us will use our sense of hearing to decode a message using voice or 
CW tones as long as "electronic detection", "electronic amplification" is 
used somewhere in the (receiver?) link. Now, try this if you are deaf - just 
put in some earplugs and see how many contest contacts you can make.
No problem, you say, do it visually, RTTY, text video, blinking LED, 
etc..... Visual is OK - we use our eyes - to see/read the message info and 
make the contact. (Yes, I know there are some that can decode RTTY in their 
head by sound.) We just decode the message with our "eyes" instead of our 
"ears". Computer (assisted ?) detection (WSJT, PSK31, etc) is OK too. Some 
deaf/blind "feel" the speaker cone to decode the CW message, even if QLF 
(look it up).

We can use any of our "senses" to make a valid contact exchange.  Does it 
really make a difference whether it's coherent or not? Auditory, Visual, 
Tactile ? The point I wish to make is you still have to make a valid contact 
exchange. My reasoning along these lines is that if we (hams) are to provide 
emergency communications (backup or otherwise), encourage experimentation, 
and increase contest activity, we should use whatever it takes to get the 
message (contact) completed.  Viz. The crew in a dark, disabled submarine on 
the ocean bottom using a hammer on the hull and the ship using sophisticated 
sonar doing a search couldn't care less if it's coherent or not. Also 
remember (1968) the U.S.S. Pueblo captured ship, when commander Bucher 
blinked this eyes using Morse code to send secret pleas for help during his 
video filmed confession - a pretty amazing feat that the North Korean 
captors didn't figure out.  We got the message!

I realize that the current discussion is about the coherence of the emitter 
and the method(s) of detection/distance, but let's not forget the bigger 
picture of what the contest and the communication "art" is all about if we 
want to encourage more experimentation and activity to that end. The more 
complicated or restrictive the rules become, the more discouraged will 
"throw in the towel" and leave. Regardless of the "mode" you still have to 
make the valid contact exchange. Please make it easy/simple.
If you read this far, thanks for patience.

Best 73's
George, WA2VNV, FN30kv
SLOP, 50-1296

----- Original Message ----- 
From: "Fred Lass" <felasstic at yahoo.com>
To: "Stanford VHF email Remailer" <VHF at w6yx.stanford.edu>; "Ev Tupis" 
<w2ev at yahoo.com>
Cc: <wsvhf at mailman.qth.net>; "Vhfcontesting Remailer" 
<VHFcontesting at contesting.com>
Sent: Thursday, December 03, 2009 8:19 PM
Subject: Re: [VHFcontesting] The meaning of coherence [was: [WSVHF] [VHF] 
VUAC Seeks Input]

Hi Ev,

I'll volunteer an answer based on my own observations.

The intent of the rule in the first place was to eliminate QSOs with a 
flashlight and eyes.

The term coherence has been questioned over the use of monochromatic LEDs 
instead of lasers.

All contestants should operate with the same interpretation of the rules.

There is no right or wrong answer and responses that are not focused (pun 
intended) are fine.

73, Fred K2TR (Hudson Division VUAC)

--- On Thu, 12/3/09, Ev Tupis <w2ev at yahoo.com> wrote:

From: Ev Tupis <w2ev at yahoo.com>
Subject: [VHFcontesting] The meaning of coherence [was: [WSVHF] [VHF] VUAC 
Seeks Input]
To: "Stanford VHF email Remailer" <VHF at w6yx.stanford.edu>
Cc: wsvhf at mailman.qth.net, "Vhfcontesting Remailer" 
<VHFcontesting at contesting.com>
Date: Thursday, December 3, 2009, 5:31 AM

As this thread becomes more incoherant (many of us don't belong to all of 
the lists cc'd, so our replies will be missed)...I keyed in on the actual 
request, "to determine if the rule should be modified to make it clearer as 
to the meaning of coherence."

Dear VUCC,
You have the advantage. We don't know...

... the intent of the rule's presence in the first place.
... the what way(s) in which the meaning of the term being misunderstood
... what problems this causes for you.

As a result, our commentary is "all over the board". Could you clarify these 
three points?

Ev, W2EV

More information about the VHFcontesting mailing list