The Art & Skill of Radio-Telegraphy

-Second Revised Edition-
William G. Pierpont N0HFF

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Chapter 20 - Learning the American Morse Code


Here we consider how to go about learning the other code.  Since most of us know the International (formerly called "Continental") code,  how do we go about learning the old ("American") Morse landline code?  Do not use the following comparative lists in any way to learn the American Morse code.  Their purpose is solely to show the differences between the two codes, and particularly the effects on the structure of certain characters due to the Morse internal spaces and the special lengthened dahs.  They affect rhythms.

First, the old Morse differs from International in four aspects:

 1)  the following characters are the same in both codes:
      A B D E G H I K M N S T U V W  4 (2/3 of alphabet letters)

  2)  a number of International characters represent different
      letters or numbers or signs in old Morse:
      MORSE:   F   J  Q  P  X  1  5  7  8  9    .   ?
      INTN'L:  R   C  F  5  L  P  o  Z  6  X    ?   /

 3)  certain old Morse letters contain internal spaces
      which make them subject to possible misinterpretation as
      two letters:  C    O    R    Y    Z  might appear
      to be         IE   EE   EI   II   SE

  4)  certain letters in old Morse are different from any
      International character for English:
      L = a longer dah ,  0 (zero) = a still longer dah (see
      below). The following numbers are different in old Morse
      from any International English character sound:  2  3  6.

This does not include other punctuation, which differs and in old Morse landline circuits was used extensively.  It must be heard to learn it.


There seem to have been no rigid "standard" timing relationships in American Morse as compared with International Morse.  That is, the duration of a normal dah is stated variously as being two times or three times the duration of a dit.  (My own impression is that it tended to be somewhat shorter than the corresponding dah in International code.  This might have been done to save time and yet to keep the careful distinctions between a dit and the definitely longer dah for  "L", which nominally was considered to be twice as long as the normal dah.) The important thing was to clearly distinguish between "E" and "L" and "T".    Zero (0) would be intentionally longer than "L" when there would be a risk of its being misread, but otherwise would be about the same.  (Some have described "L" as being as short as 4 or as long as 7 units, and zero as short as 5 or as long as 10 units.  There seems to have been better agreement on the spaces.)

The important thing was "This is communication.  Things should have to be sent only once.  Having to repeat wastes time and money."  Are the words and numbers being clearly understood by the receiving operator?"   Commercial telegraphers were rated by their accuracy first and speed second..

In the same way, the space in the internally spaced characters (3 above) is usually stated to be the duration of two dits, but tended to be shortened just enough to be clear, so the receiving operator would not be confused.  The spacing between letters in a word nominally appears to have been the duration of 3 - 4 dits, and between words about the length of 4 - 6 dits.  Before and/or after the internally spaced characters a slightly longer than normal letter space was often felt necessary, depending on the code environment..  Again, these values would tend to vary according to the skill of both operators.  The object was, as always, perfect copy with minimum time to transmit, leaving considerable flexibility to the individual operators.  Yet the demands of this code for accurate proportioning  -- intolerance of the least bit of hesitation, key up or key down (e.g., the person who sent the word "telegraph" in such a way that it was copied as "jgraph") -- show how much more acute timing is in American Morse in contrast to International Morse.


Three general features distinguish old Morse from International Morse code:

At first sight, with some characters the same and others different, confusion between the codes might seem considerable in learning the other. -  Take heart!  In a personal letter in 1942  Mr. R.  J. Miller, a skilled teacher with the old Teleplex Co., wrote: "One who is expert in only one code, e.g. American Morse, can master Continental Morse in ten days to two weeks and be as expert at the new code as he was in the old code.  This is because his mind is trained to recognize the quick sounds.  This theory has been proved many a time."

Notice his words carefully:  "expert" and "his mind is trained to recognize the quick sounds." These are not trivial words.  It is the operator who already can handle the one code like an expert, because his mind has been well trained to recognize the letter sounds instantly when they are sent at a good speed, who is going to learn so fast and well.  Just how Mr. Miller defined "expert" is not pinned down, but we can assume that such an "expert" was better than the minimum requirement for a commercial radio operator of those early days.  It is probably safe to say that a person who can easily handle the code somewhere in the 25 - 35 wpm range will find Mr. Miller's words to be true, if he puts himself to it.

From this we may assume that those of us who are less skilled and want to learn old Morse may expect to take somewhat longer to get there.  (Is it possible that in learning the second code in the proper way we may actually improve our skill in the code we already know, since immediate character recognition is the key point?)


How should we go about learning old Morse? --  First of all, we have to hear it properly sent, because its rhythms are different.  We should have little trouble with recognizing it on the air:  its peculiar rhythms and "dittiness" will quickly identify it.  But also we will find we can easily read many common words because they sound the same in both codes ( e.g. "and, the, it, but, these, thing," and many others) -- that's an encouragement: we don't have to relearn their sounds.  Listen to get the swing of it, then practice with your key, imitating the experts.  This will help reinforce the sounds.

Consider the following suggestions:

l) just ignore the idea of possible confusion: over the years many operators with various degrees of skill, from quite modest to expert, have managed to use either of both codes with no difficulty.  In early "wireless" days a commercial operator was generally required to do this, and many of them were not very fast operators.

2) you already know two-thirds of the alphabet and one of ten digits:  so you don't have to give these any special thought at all.

3) think of all the characters that are different -- different in the one code from those in the other separately.    Learn and think of each one of them  as part of the code system to which it belongs. Don't mix or compare them -- keep each one separate and distinct from the other:  (For example, don't under any condition let yourself start to think:  that's "C" in International so it is "J". in Old Morse)  There must be nothing standing in between the signal you hear and its immediate recognition as being the letter.  (A person who knows German as well as English knows that the letters  ch  are pronounced differently in German than in English -- there is no confusion at all.  We need to think the same way here.)

4) remember that learning old Morse is going to be much easier and faster than learning International code because we already know how to go about it and that many, many others have succeeded well.  This ought to give us great encouragement and confidence.

Some excellent suggestions come from those who have long known and used both codes.  One of these is to use a Morse sounder instead of audio tones to provide a completely different sound environment to help distinguish Morse from International.  (If this is done, one needs to get familiar with receiving by sounder.  See below.)   If one does not intend to use a sounder, there is no point in practicing with it.  Some experienced operators see no benefit from it.

So there need be no confusion at all.  We can simply go ahead and confidently learn the old, but new-to-us Morse code and enjoy it, using the principles already set forth here.  Perhaps some of the old timers who have learned them both long ago may be pleased to give us some additional advice from their experience also.

[Expertly-sent Old Morse tapes may still be available from Cecil Langdoc, 201 Homan Ave.  Elkhart IN 46516.  They make for great listening.]

A Railroad telegrapher's story:--  a beginning operator was sending as fast as he could with a bug when the other operator cut in with what he copied as "REND STOW IMA GIRT".  He asked for a repeat and got the same copy.  He turned to his supervisor and asked: "What's wrong with that operator?"   The reply: "Nothing, she's just saying 'Send slow I'm a girl.'  You've gotta learn the difference between  R  and  S  and T  and L. Didn't they teach you anything in that school?"

Here is an example of all-dot" sentence":  Her Irish eyes cry cos she is so sorry.


Learning to read by sounder is no more difficult than by tone or buzz.  It is just different.  The sounder makes two different kinds of "clicks" which correspond to movements of the key.  The down-stroke produces a sharp (high pitched) click to denote the beginning of the "on" signal.  The up-stroke is a duller sound, indicating the end of signal ("off").  The length of the intervening silence between them corresponds to the duration of the code element, distinguishing a dit from a dah.   Practice first with a string of dits and then of dahs till you get the hang of it, and then with some common words until you get familiar with this method of hearing the code signals.  (Use letters which are common to both codes -- see l above.)  You will probably find it interesting and a challenge at first.

American Morse was designed for operation over wires, where static and other interference are absent or minimal.  Although the International form of the code was developed and adopted in Europe only 5 years later, in America the earlier code was first used for wireless.  Two factors probably acted to effect the change-over: the predominantly "ditty" character of American Morse sounded more like static than the International form, and the world-wide nature of shipboard wireless operation urged a common code.  This would have become more demanding as international commercial and amateur operation became commonplace.


American Morse telegraphy is considered by many of its practitioners as a thing of beauty, a work of art. The "tune sung out" by a local sounder "outranks the most precisely tuned aircraft engine in terms of sheer beauty", according to one old timer.


If the identical duration of the basic unit of time (the dit and unit space) is used for both codes while sending the same message, the skilled American Morse operators will have completed the message while the International operators are still sending and receiving.  The message will in fact actually have been handled at a rate about 45% faster* on the Morse line than on the International channel.

  *) Here the skilled old Morse operators will normally be using shorter dashes and spaces (as noted above) than their Inter-national peers.  This, combined with the 73% shorter average letter and 65% shorter number in old Morse accounts for the apparent discrepancy between the previously cited 10% faster.

Therefore, when we read of the speeds achieved under American Morse operations we need to recognize that the sending operator is having an easier time than the corresponding International operator, but the receiving operator is under the same burden, but needs a more acute ability to discriminate small differences than his corresponding International operator.

In addition, when both have completed sending the message, the Morse operator will have used only about 91% as many keystrokes and about 85% of the total work or energy expended by the International operator.

These gains are achievable at a cost.  First, the American Morse operator must learn to make some finer distinctions in sound than the International operator.  He must readily recognize the internally spaced letters (C O R Y Z) and the lengthened dah characters (L and zero) as distinguished from what might be their equivalents, and he must generally live with closer spacing between characters and words.  There is also the problem of the difference between reading by sounder in the telegraph office and reading signals over the air where static and interference can cause loss of signal components.

Ambiguities introduced by the spaced letters and the shorter dahs in American Morse under radio operation stand in sharp contrast to the standardized durations in International, making the latter easier to interpret under adverse conditions.  I suspect that Old Morse operators under radio conditions tend to lengthen (or exaggerate) their time intervals (signal "on" and spaces) to aid in copying.  If they  do so, then the time gain is less.


Words which contain only letters common to both codes:    (a e i u  b d g h k m n s t v w)

the and end man men view stew must mist missed kid king thing dig dumb  sing sting stub hide side vast waste waist medium wide stab tug aim bug tame name magnet tube gust huge India ink sink had mad made human magnitude dean heat hum ham him sad dash dish shade gush bush hush mash smash biggest mug hug bag sag wag stage wages vague stag that tug heed head hasten skate hate date night might kite fight invite begin began behave behead aghast mane tame inane game wane hank bank stink wink

Words containing only the Letters Unique to American Morse:

Dits Only:

cheese choose coop cop cope copper copy core creep creepy crop cross cry echo eyes hoe hope horse hose ice ooze peer pie pieces pose precise press price prize prose recess repose rice ripe rope Roy seer seize series she sheer shoe shy size sore spice spree spy yippy zero zoo

Only Letters Unique to American Morse:

clop  color  crop off  for  joy  fly  lop  offer plop  roll jolly

Using Only the Letters Unique To American Morse Plus The Rest Of Its Vowels:

all aloe career clap clay clear cliff clip clique collar cruel equip expire explore fall fall fill fizzle flail flare fly for full fail jail jeer jello joy jury leap lily lop oil opera pear peel place play  quail queer quip quiz  rap reaper repair rill roll xray year zeal


From the MILL 72a opnotes of Jim Farrior who originally learned American Morse:--

A considerable variation exists in the way American Morse is sent by different operators, and there is no rigid standard. Although it is not typically sent exactly that way, it is convenient for some purposes to assume that the Morse standard is the same as the CW standard, except that certain Morse characters contain a wider space between two of the dots, and the Morse word space is 1 unit shorter than the corresponding CW space.  Also, Morse L is a dash approximately twice the length of the standard dash, and the Morse zero is a dash approximately three times the length of the standard dash. This results in the following Morse "standard": dot = 1 unit, normal space = 1, special Morse space = 2 units, dash = 3 units, Morse L = 6 units, Morse 0 = 9 units, character space = 3 units, word space = 6 units.

Although I haven't spent much practice time with learning American Morse, it isn't easy to for me to distinguish the different lengths of dahs and to perceive the spaced characters as units, rather than e's and i's,  without paying close conscious attention to them.

My suspicion is that I have for so many years been trying to read poorly sent International Morse that my perception of these small differences in length and spacing has become badly desensitized. -- American Morse operators could never have lived with that kind of carelessness.  They would have shuddered at such sending. -- Poorly formed International Morse, where the dits and dahs are often grossly distorted: on the one hand it is sometimes hard to tell the difference between dragging long dits and clipped dahs, and on the other where the dahs are far, far too long for the sending speed, with many simply irregularly sent.  Add to that the careless spacings internally between letters within a word, and one has to do a lot of mental adjusting to understand such poor sending.

The Art and Skill of Radio-Telegraphy-Second Revised Edition-
©William G. Pierpont N0HFF