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Author Topic: Iambic vs non Iambic: evaluating the myth (new ed. of the book ZART available)  (Read 8848 times)
IK0YGJ
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« on: August 13, 2010, 12:39:39 AM »


     Hi all,
     being a QRQ addicted and an Information Theory freak I could not resist
     to make an analysis of Iambic and non Iambic modes, from an Information
     Theoretical point of view. I counted the letter distribution for five
     languages (italian, english, german, spanish and french) and evaluated
     the average number of key press to be expected in manipulating a
     straight key, a bug, a non iambic single lever key and a iambic paddle.
     Here are the results:

     - Letters that can be emitted using the squeezing technique, are far
     from negligible, they are frequent from a range of 16,43% for the
     German language to 18.96% for the Spanish language.

     - The manipulation of a bug, non iambic single-lever, iambic twin lever
     paddle can be regarded as a “compression” of the manipulation of a
     straight key. Different compression ratios are evaluated for the five
     languages, with a peak of 40,6% for iambic, twin-lever keying in
     English language.

     - Iambic keying is the most efficient keying technique, resulting in an
     overall compression rate ranging from 11,3% for German to 13,1% for the
     Italian language (compared against non iambic keying).

     You can find the whole study with method and tables. in the last
     chapter  of the new revision of the book ZART, freely downloadable
     here:

     http://www.qsl.net/ik0ygj/enu/index.html

Here is the last paragraph discussing the conclusions.

Single vs twin lever keys: evaluating the myth

From a statistical point of view, then, there is no doubt that the most efficient
manipulation technique is the iambic twin lever. Such efficiency is even more
improved when using Iambic mode B with dot and dash memory, since this mode
reduces further the time (and, thus, the effort) needed to keep paddles pressed.
Even if rare, iambic letters are, collectively, likely to be transmitted in a good
portion of the QTC (around 18%) and, especially in QRQ, they must be treated
properly by the operator, who must rely on good iambic keying skills to avoid errors.
Why, then, the world champions use single lever keys instead of twin lever
paddle ?
Iambic keying has a significant drawback: the lack of mechanical feedback. In
iambic mode the operator is not aware when the keyer will emit the next alternating
dot or dash, while squeezing. At higher speeds (40WPM and above) this fact
augments the probability of making a mistake. In HST competitions, maximum 3
uncorrected mistakes are allowed and each mistake must always be corrected to avoid
penalties.
The form factor of a single lever key is also important. When manipulating a
single lever key built according the specifications for HST, with a long lever and
pivot point at the end, the operator feels in an unmistakable way the feedback of each
contact closure. On the other hand, to move such a lever a greater effort is indeed
required. All in all, during competitions the operator privileges feedback accuracy at
the price of some more fatigue: better making some more effort and be sure of
avoiding mistakes. Even at lower speeds (30 WPM or less), HST keys are so precise
that the operator feels some sort of “buffering”, i.e. he has the sensation to “key in
advance”, by closing first the contact and then feeling the sidetone in return. It is
thanks to the strong mechanical feedback that the operator does not even need to hear
the sidetone itself, since he already felt the contact hit returning at his fingers.
All these advantages have their own price: the operator must move the key
lever more times (we saw about 12% more). Accuracy in change of muscle effort, a
quite fair trade for a competition and also for QRQ operation in general. At lower
speeds this trade might be less favourable, depending on operating style and personal
taste. However, 12% more effort is far from negligible and, for long rag-chew QSOs
it might yield too much fatiguing with respect to a conventional twin-levered paddle.



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W4YA
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« Reply #1 on: August 13, 2010, 05:08:45 AM »

Carlo,

Very interesting to actually see statistics.

In 1967 I built a keyer designed by W9WJB (now W6DZ) called The 9TO Mark II Keyer.  See QST June 1967 p. 15. This keyer was not iambic, but featured a single dot insertion.

If you closed the dash paddle, and then the dot paddle, and held them closed, you would get a string of dashes and ONE dot inserted in the string. So K, N and Y etc. would be sent with one squeeze of both paddles.

I found that keyer to be almost foolproof, whereas iambic is almost impossible for me to control.

73, Jim W4YA
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N3QE
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« Reply #2 on: August 13, 2010, 11:17:41 AM »

I personally am a devoted user of Iambic B but I wouldn't try to prove its superiority to a non-believer by using statistics. IMHO it'd be like trying to prove that a religion is right by using statistics.
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N7DM
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« Reply #3 on: August 13, 2010, 02:51:16 PM »

*DEAD-ON.*.. 'QE'...    [Myth, my 'donkey'...]
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IK0YGJ
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« Reply #4 on: August 14, 2010, 02:04:33 AM »

Hi all,
purpose of the work is not to demonsrate the superioriy of Iambic. Actually what happens is that there is no "one size fits all" with CW. Mono non iambic are perfect for QRQ and higher precision keying, Iambic for long qso rag-chewing "armchair" style.
That's it !
73 Carlo
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N3QE
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« Reply #5 on: August 16, 2010, 06:22:17 AM »

Hi all,
purpose of the work is not to demonsrate the superioriy of Iambic. Actually what happens is that there is no "one size fits all" with CW. Mono non iambic are perfect for QRQ and higher precision keying, Iambic for long qso rag-chewing "armchair" style.
That's it !
73 Carlo
Applying information theoretics to CW will not really be grasped by much of the community because the current system is so steeped in tradition.

I personally find it interesting that many ways of choosing information were chosen specifically because of efficiency, e.g. letters "E", "T", "I", "A", "N" are very common in English and also the shortest in CW.

But there are oddball cases (e.g. "O" is actually more common than "I" but takes much longer to send in CW) so trying to say that information theoretic things are strictly applicable, will fall down in many places, and you have to allow for that in your discussions and phrasing, that the tradition is there through a century+ of practice and nobody's gonna change it no matter what an information theory textbook might say.

And I think that Europeans often step on religious sensitivites that Americans avoid stepping on. It might be cultural, or maybe even language-based, but we're extra careful not to try to make it sound like statistical studies show that one religion is right :-). And when it comes to CW and hams that use CW, it really is a religious issue.

Tim.
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IK0YGJ
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« Reply #6 on: August 16, 2010, 06:35:20 AM »

Hi Tim,
you are right but, really, right.
1. Yes: true, the distribution frequency applied in defining morse code has some discrepancies. In fact, the correct order it is not strictly used to assign codings to the letters. What is published in the book is a mere evaluation, where as you can see results that CW in german is even more efficient than in english. Please notice that the distribution table I used were taken from Wikipedia and are not necessarily the same applied one century ago.
2. Yes, again, in Europe (and most of all in Italy) we are less pragmatic and tend to consider things more from a "faction" point of view than after a thoroughful analysis.
But we can still work on it ! That's why studies are needed, as well as the discussion on their outcome ...
73 Carlo
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N3QE
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« Reply #7 on: August 16, 2010, 06:57:11 AM »

2. Yes, again, in Europe (and most of all in Italy) we are less pragmatic and tend to consider things more from a "faction" point of view than after a thoroughful analysis.
But we can still work on it ! That's why studies are needed, as well as the discussion on their outcome ...

To tell you the truth, most Americans would NOT think that a religious freedom issue needs any thoughtful analysis, or pseudo-scientific or pseudo-statistical ranking study at all.

Comparative religion does exist as an academic subject but is simply not discussed in polite American discourse in pseudo-scientific-statistical ways that a European would use.

That might be the gap here. And CW is as close to religion as you will get here.

More broadly this might account for many things that Europeans don't get about Americans :-).

Tim.
« Last Edit: August 16, 2010, 06:59:53 AM by Tim Shoppa » Logged
W5UX
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« Reply #8 on: August 20, 2010, 02:47:57 PM »

I apologize for being a little off subject but you should check the video where Carlo demonstrates learning to use a cootie key on utube.  He does a great job. I bought one a week ago and just getting the hang of it.  Should be pretty good by the end of the year. Am using my left hand for it.  The right one is pretty beat up.

73 de W5UX
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STAYVERTICAL
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« Reply #9 on: August 20, 2010, 03:30:39 PM »

Iambic, single lever, twin lever, bug key, PC-keyboard it does not matter - all of these are not real CW sending.
The only real CW sending is using a straight key.
Every one of these "devices" is blurring the interface between the human interface and the eventual CW signal.
They are a chronology or fossil record of the path of CW-mans attempts at making it easier to send CW.

I am not suggesting that people should not use these devices, and sure, they each have a different level of
technology required for operation, but nevertheless, they are still robot-assisted CW sending.

I personally have no problem with any of these devices, and I use a semi-automatic bug and PC keyboard depending
on my mood - I even break out the straight key when I want to punish my CW contacts.
But I still find it amusing to see posts which purport to evaluate the relative merits of the various robotic CW sending
modes. I am sure that there would even be a group who would happily use automatic keyers with memory functions and
frown on PC keyboarders.

I take pride both in my own and others ability to RECEIVE high speed morse, sending is really just a side issue, unless of course
you are fast on a straight key.

Flame away.
73s
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9V1VV
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« Reply #10 on: August 20, 2010, 06:01:36 PM »

Hi, erm, Stayvertical

I think most of us would agree with you that the straight key is the purest form of CW. This was the way I was forced to learn at radio college years ago before going to sea as an R/O. Anything else was frowned upon.

But like most straight key ops I start to suffer when sending faster than about 28 wpm, so the only way to send faster is with a robot key. Perhaps the bug is the best compromise between aesthetics and practicality.

Small flame - using an anonymous tag tends to distance the writer from the reader. This technique  is similar to  the  use of the omnipotent, authoritarian narrative  used in the realist novels of the 19th century. I would give it up if I were you.

73 John / 9 V 1 V V
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STAYVERTICAL
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« Reply #11 on: August 20, 2010, 08:10:30 PM »

Hi, erm, Stayvertical

I think most of us would agree with you that the straight key is the purest form of CW. This was the way I was forced to learn at radio college years ago before going to sea as an R/O. Anything else was frowned upon.

But like most straight key ops I start to suffer when sending faster than about 28 wpm, so the only way to send faster is with a robot key. Perhaps the bug is the best compromise between aesthetics and practicality.

Small flame - using an anonymous tag tends to distance the writer from the reader. This technique  is similar to  the  use of the omnipotent, authoritarian narrative  used in the realist novels of the 19th century. I would give it up if I were you.

73 John / 9 V 1 V V

Hello John,

I am not insinuating it is wrong to use mechanical or electronic assistance to achieve higher speeds and in many cases more accurate sending.
Having spent time at sea, I quickly migrated to a Katusumi electronic keyer as soon as I could.
I love using electronic keyers or bugs, finding the rhythm very relaxing and zen like.
Typing on a keyboard just does not engage the same parts of the brain, and distances one from the experience.
However, since speed is no longer any obstacle using electronic methods ( I have heard two keyboard ops using 100wpm in a psk31 like qso), it is somewhat anomalous to take this into account.

I am also pleased to meet another fan of 19th Century novels and writing.
It is insightful to see the same attitudes, problems, hopes and aspirations reflected in writings from over a hundred years ago - and how wonderful that CW was there at the same time.

Regards es 73s
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IK0YGJ
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« Reply #12 on: August 22, 2010, 12:57:02 AM »

Hi erm,
your message, even if OT, opens a very interesting front of discussion: is there any "real" CW still alive ? However, in this topic we are discussing about effectiveness of iambic vs non-iambic and posts on this line are the welcome to tell about our own experience in iambic keying.
If you open a new topic I will be glad to discuss it, there are a lot of things to talk about ...
73 Carlo
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NI0C
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« Reply #13 on: August 22, 2010, 11:09:38 AM »

N3QE made a few references to religion, including: "And CW is as close to religion as you will get here."

I'm not sure I agree, except that experienced practitioners of CW sometimes can be dogmatic about what works for them and what doesn't. 

Many thanks to Carlo for updating his already excellent book on radiotelegraphy to include his studies of what is theoretically possible using iambic keying.  Also many thanks for making the book freely available to us!

I've been using iambic keyers and iambic paddles for several years now; however I still tend to use single lever techniques that became habitual for many years before that.  So in my practice, I probably don't achieve anywhere near the theoretical advantages that others, less biased in their learning, can with the iambic keyer. 

73,
Chuck  NI0C

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9V1VV
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« Reply #14 on: August 22, 2010, 09:45:29 PM »

Hi Erm, Stayvertical,

actually I regretted sending my last post... it sounded a bit arrogant, which I did not intend. Hope to work you on air some time.

Carlo... your research into iambic has softened the conclusions reached by Marshall Emm a little. He reckoned that the advantages of iambic were outweighed by the increased chances of errors at high speed. But broadly, I think your findings agree with his.  Single paddles seem to rule at high speed.

73 

John
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