[Elecraft] Lids running RTTY on the JT65 Frequency

[Edward R Cole]

When Harry first posted
 >On 1/5/2015 5:50 PM, Harry Yingst via Elecraft wrote:
 > JT65 is indeed audible and has a very distinct sound.

I was tempted to reply when first posted but decided it wasn't worth 
bothering since it was obviously from someone who totally did not 
understand.  But now it has been repeated, so you asked for this (and 
I am replying politely):

If you stand next to a horn being played, does it make a sound?...if 
you are a thousand miles away from the horn does it still make a 
sound?  Yes to both questions.  But can you hear the sound when you 
are a thousand miles away?  Not by ear.

Is CW audible in a radio receiver tuned to receive it?  Yes - If the 
signal is strong enough.  If you cannot hear the CW signal can you 
copy the CW message...nope.

JT-65 can be heard by a receiver set up in CW or SSB and properly 
tuned...if the signal is strong enough.  If the signal is not strong 
enough to be heard, the JT65 signal can still be decoded (quite 
easily) though you will hear nothing in the receiver.  This is at a 
signal level from about -20 to -28 dB SNR as received with a 2.5-KHz 
bw SSB receiver.

To state this a little differently, JT-65 can be decoded down to 
about 8-dB below the signal level that CW is not longer 
audible.  JT-65 and CW are equally audible if the same signal strength.

73, Ed - KL7UW
PS: if you do not like computers why are you using one to post 
e-mail?  If you prefer CW, then by all means use CW.  JT-65 is simply 
an alternative mode which works better with extremely weak 
signals.  Human intervention is required for either mode.  To say 
JT-65 use is not human-to human is insulting the user.

-------------------------
From: "Wes (N7WS)" <wes at triconet.org>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Lids running RTTY on the JT65 Frequency
Message-ID: <54B55338.1040007 at triconet.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Well, if it's audible, then why not use CW?  Much faster, even with 
slow keying,
and they are human-to-human contacts.  The bragging I've heard is of the type,
"I worked VK0H with 100 mW into a wet string antenna laying on the 
ground.  Who
needs QRO?"
==snip
X.



73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
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