DJ5CW's Ham Radio Stuff

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All kinds of things too precious not to share, in short articles. Constantly under construction or destruction. Note that code snippets are usually working minimum examples (often stripped of extra features). If you plan to use and of the code for anything serious, you may want to contact me. It's likely that I can provide you with some updates and good (?) advice. fabian@fkurz.net


Fabian KurzHam RadioStuff


How does CW head copy at high speeds work?

There are some myths and some facts about copying high speed morse code. One is that you are hearing complete words as single units. That's neither right, nor wrong. I tried to explain how it works for me in this usenet posting a while ago.

From dj1yfk Thu Oct 11 17:16:05 2007
From: Fabian Kurz 
Subject: Re: Wall Street Journal Article on Morse Code
Newsgroups: rec.radio.amateur.moderated
References: <1191980352.867743.318960@d55g2000hsg.googlegroups.com> 
User-Agent: tin/1.6.2-20030910 ("Pabbay") (UNIX) (FreeBSD/5.3-RELEASE (i386))
Message-ID: <5n6t3dFgihn3U1@mid.dfncis.de>
Date: Thu, 11 Oct 2007 15:16:05 -0000

Bert Hyman wrote:
> "Like all Morse experts, Mr. Adams rarely breaks signals down into
> letters, instead hearing complete words much as readers recognize words
> on a page. When he transcribes a message at high speeds, his fingers are
> five or 10 words behind his ears." 
> 
> I've been licensed since 1961, and I've heard and read things like this 
> ever since. 
[...]
> It's probably way too late for me to get over 45 years of bad habits,
> but how do people achive this state? 

Like you, I have heard and read about this often (copying whole
words rather than single letters), and I think it is a little bit
misleading. I can easily copy plain text CW in German or English
at around 80 WpM, but still, if I actively, consciously listen, I
*do* hear every single letter. 

But that does not mean that I have to concatenate those letters
to form a word, like a first grade pupil does, when he reads an
unknown word (I also recently encountered this problem again
while learning Macedonian, written in cyrillic letters!). I
rather make an assumption on what the word could be, often even
before the word is transmitted. By making such predictions (and
in most sentences you can easily predict the following word; or
if not, you can predict the word based on the first letter, or
make some rough assumptions of what might come next), you can
stop to worry about the word after you have recognized the start.

If, however, an unexpected word appears, you have to change the
plan in your mind, and decode it consciously. In most cases
again, the first two or three letters will be sufficient to make
a safe assumption on what the word will be. In cases of unknown
names (operator, QTH, ...) you might have to go back to putting
it together letter by letter.

I think everyone copies plain text CW similar to this, to a
certain degree. It starts with your first standard QSOs: Those
ever repeating phrases ('tnx fr rprt = ur rst 599 ='...) are soon
'hard coded' into your brain. They are so easy to copy because
it's what you *expect* to hear. If the other station suddenly
starts sending something _unexpected_, you're getting into
trouble or at least you'll suddenly have to pay close attention.
The reception is moving somewhere from your subconsciousness to a
higher level of consciousness. 

After my first 50 CW QSOs, I stopped to write down every single
letter, and only had to write everything that was not the
expected stuff like "my name is", but the names/QTHs itself. 

So, hearing a whole word as one 'sound' does - in my personal
experience - not work, you still hear it letter by letter. But
the more routined you are, the deeper the process of perception
slides into your subconsciousness.

73,
-- 
Fabian Kurz, DJ1YFK * Dresden, Germany * http://fkurz.net/

You may also find interesting what Tommy, W4BQF has to say about this subject.

Added: 28-Jan-2008. Last modified: 28-Jan-2008.


Fabian KurzHam RadioStuff