Morse Code Keys and Keyers

- overview of the different types of Morse code keys and keyers or CW keys used in radio communications and in particular within amateur radio or ham radio.

In order to send Morse code it is necessary to have some way of keying the signal. There is an enormous variety of Morse code keys and Morse code keyers available, each of which is capable of sending Morse code in one form or another. Over the years since the first Morse code telegraph, there have been many styles of Morse code key that have been used. Nowadays, the greatest use of Morse keys is within amateur radio or ham radio where the yare sometimes called CW keys as a result of the form of radio transmission. In addition to their use in ham radio there is still some limited use of Morse code in professional communications, and some historical telegraph systems demonstrate the use of Morse code.

Before looking at the variety of Morse code keys and Morse code keyers that are available, it is possibly worth putting them in context by looking at the development of Morse code and Morse telegraph history.

Morse code and Morse telegraph history

The first Morse telegraph system was set up between Baltimore and Washington DC in the USA. Samuel Morse, its inventor sent the first message which read: "What hath God wrought" over the line on 24th May 1844. After its initial demonstration, the idea for the system spread quickly, and before long, Morse telegraph spread out first over the USA and then over world connecting the world in a way it had not done before.

With its ease of use, and simplicity the Morse code system lent itself for use by the newly invented system of wire-less communications. Using this technology in December 1901, Marconi sent the first wireless message across the Atlantic, further shrinking the size of the world. Over the following years, the Morse code system continued to grow in its use as telegraph systems used it along with radio communications.

As technology developed, new and more sophisticated forms of communication became available and the use of the Morse code declined. Teleprinter that used a keyboard to enter messages were introduced and these provided a printed copy at the far end. In Britain the Post Office discontinued the use of landline Morse code in 1932, although its use continued until the 1960s in both the USA and Australia.

The main area in which Morse is used today is for radio transmissions, although new technology again supplanted the use of the Morse code. As an indication of this, the requirement for ships at sea to be able to send Morse code distress signals ended on 31st January 1999. Some ships still use it as a cheaper option than the satellite communications systems that are in general use now. Also some armed forces still use it as a last ditch form of communications.

The main use for Morse code is within amateur radio or ham radio. Here many ham radio operators still like to use Morse code because it gives them the ability to make ham radio contacts with simple low powered equipment.

Types of Morse key

There are several types of key and keyer that can be used today, ranging from "low-tech" hand keys right through to highly sophisticated electronic keyers using the using very complicated software and digital techniques. Broadly speaking they can be grouped into the following areas:

1. Straight Morse key:   a traditional Morse key using a lever and handle.



2. Side swiper:   A form of key that uses a side to side movement to make and break the contacts.



3. Semi-automatic mechanical keyer:   A mechanical keyer with a "paddle" used by the operator and uses a weighted arm to automatically make a series of dots



4. Electronic keyer:   Various versions of electronic keyers are used that have a "paddle" and the ability to automatically create dots and dashes



5. Morse keyboards and automatic Morse generators :   A variety of electronic based products that are able to use digital technology to generate Morse code.

Straight Morse key

This type of Morse key is still in widespread use by many Morse enthusiasts including ham radio operators. The basic key consists of a lever with a bearing of some form in the centre. A handle on one end is moved up and down to make and break a contact and thereby provide the keyed signal.

A very crude form of this type of key was used by Alfred Vail who was working for Samuel Morse on the early development of the Morse key. It consisted on a lever with contacts and a sprung strut used to keep the contacts open. The key, although crude was very successful. However as the Morse telegraph system grew in popularity, the Morse key was developed further.

The balance of a Morse key is particularly important. This is very true when operating at high speed. To improve the balance of the key, an early development used around the 1850s and 1860s was known as the Camelback key. This key gained its name from the shape of the lever. This form of key was popular with the early American telegraph operators, and many versions were also seen in Europe, although they are not manufactured today.

Although the Camelback gave some advantages over previous keys, telegraph operators wanted to find keys that were easier, quicker to use and cheaper. As keys were being used in much greater numbers, the was plenty of impetus for improvements in Morse code key technology to improve.

The next major step forward occurred when James Bunnell introduced his "Triumph Key" in 1881. The basic design involved a steel lever with an integral trunnion or fulcrum. A hollow oval frame made the key very light and easy to use. These keys provided a number of advantages. Early keys suffered from the fact that the lever would come loose from the press fit trunnion. As a result of the improvements this style of key was produced in large quantities by a number of companies including Western Electric, Signal Electric and of course the Bunnell company itself. This style of Morse code key is still in widespread use today.

The Morse keys used in Europe tended to be heavier than those used in North America. The lever was often manufactured from solid brass and the overall assembly was considerably heavier. Typically these keys were used in fixed locations, rather than the telegraph operators of North America who carried their won keys with them.

Today it is possible to buy keys of designs similar to both the North American Steel Lever Key and the heavier versions like the British Post Office keys.

In addition to the Morse keys used for normal telegraph and radio operation from a fixed area, some specialised Morse keys were produced. Many had covers and many Morse code keys used for maritime operation tended to have covers. In addition to this, some specialised Morse keys were used for aeronautical applications. One interesting variant was what is known as the "Bathtub" Morse key. This key was developed for use on British WW2 bomber aircraft such as the Lancaster bomber. This Morse key was completed enclosed, the idea being that it prevented fumes getting to the key contacts and any sparked there prevented from causing an explosion.

When choosing a key for personal use, it is necessary to have one that feels comfortable. It is very much a matter of personal preference, and there is a wide selection from which to choose. The adjustment is also important. The gap between the contacts should be adjusted to suit. Often wider gaps are used for slower speeds where it is possible to have time for the additional movement, and much narrower gaps are used for faster speeds. The key should also be mounted so that the wrist is supported, and this is important when long spells of operating are envisaged.

Sideswiper Morse key

Despite the many improvements made in Morse keys, difficulties were still being experienced by telegraph operators who were working long hours and suffering from wrist pain known as "telegraphers cramp" as a result of what today would be called "Repetitive Strain Injury", or RSI. To help overcome this Bunnell introduced a new form of key in 1888 known as the sideswiper. Instead of using an up and down action the sideswiper used a side to side action with contact being made when the key was moved to either side. A rest or off position was in the centre.

These keys are not normally used these days and few if any are manufactured new. They also require a new way of thinking when they are used. Rather than an up and down movement, they move from side to side and there are two contact positions. However it did significantly reduced the incidence of telegraphers cramp.

While the Sideswiper did not catch on in a huge way, it set the scene for the next development that forms the basis of electronics keyers used today.

Semi-automatic mechanical keyer or "bug" key

The next step in the development of keys was the semi-automatic which is also often called the "bug" key. The first bug key was introduced by Horace Martin when he developed a key he called the "Autoplex." This was battery powered and had a vibrating arm to generate the dots. Production of these items was very slow and only continued until 1905. However in 1904 Martin introduced a mechanical bug in 1904 he called a Vibroplex. It used a vibrating arm to generate the dots. Martin filed the patent for his idea on 7 May 1904, but he was not the only person working along these lines. A man named William Coffe filed a patent on 11 January 1904. This was very general in its wording encompassing many aspects of keyers, and as a result it was granted after that of Martin's. As a result many legal battles were fought. The Vibroplex was very successful and can still be bought today.

Vibroplex and other forms of mechanical semiautomatic Morse key are still in widespread use. After using a straight Morse key, they take a little practice to get used to. Also it is necessary to be very aware of setting up the contacts so that a 1 : 1 mark space ratio is achieved on the dots and that when sending, the ratio between the dots and dashes is accurately maintained. It is very easy when using these keys to send Morse code that is not particularly easy to read. However when they are correctly set and being used well, they provide a good method of sending high speed Morse code. A further point to note is that these bug keys are not suitable for keying high voltages or currents, of for switching any loads that are inductive. The reason for this is that small sparks are created that soon burn the contacts and form pits on them. Also these keyers tend to create clicks as the make and break action is not particularly positive. Accordingly the key click filters on the transmitter should be checked to ensure they can accommodate this.

Fully automatic electronic Morse keyers or "El-bugs"

With the advancement of electronics, fully automatic keyers that generated dots and dashes were eventually produced. Some of the earliest designs date from the 1940s, one even appeared in the April 1940 edition of QST, the magazine of the American Radio Relay League. Since then considerable developments have been made in terms of Morse keyer technology.

The original paddles used for the sideswiper and later the semi-automatic bug key has been further developed. A system of two paddles side by side has been introduced to provide what is termed a "iambic" mode. Here if the left paddle is pushed to the right, a series of dots is made. If the right paddle is pushed to the left, a series of dashes is made. If the two are squeezed together dots and dashes are interspersed. This considerably helps with the sending of high speed Morse code.

The technology for these keyers has been further enhanced and most are now able to store strings of letters or preset messages. In this way for ham radio contests, or other forms of operation, frequently used messages can be stored and sent quickly and accurately.

Nowadays, many ham radio transceivers include the electronics circuitry for the Morse keyer. All that is required is for the external contacts for the Morse paddle to be made to the transceiver. In view of this only the paddle is required, and as a result, fewer complete keyers are available and sold.

Morse keyboards and automatic Morse code generators

Today, there are many processor or computer driven Morse code generators. Morse keyboards can be very useful when wanting to generate long Morse transmissions. While these seem to be items that were a recent invention, it is surprising to learn that the first step in the automation for generating Morse code signals occurred as far back as 1902 when Charles Yetman received his patent for what he called a telegraphic transmitter. Unfortunately this idea was well ahead of its time, and the unit consisted of a typerwriter keyboard that converted the key depressions into Morse characters. The idea did not catch on because the unit was large and expensive. However it showed that it was possible to generate Morse code automatically.

Automatic generation of Morse code had to wait until home computers like the Apple II and the first IMB PCs became available in the early 1980s. With the further development of PCs and sound card technology, full packages became available that could not only send Morse but also decipher it as well. Although these Morse coder readers are not able to copy as well as the human mind under conditions where interference levels are very high, they are nevertheless able to provide good copy under many conditions.

Summary

The development of Morse code keys has come a long way since Alfred Vail manufactured the first key for the inaugural line in 1844. Since then the straight Morse keys have become much easier to use, and they are also widely available for very competitive prices. In addition to this many other types of Morse keyers have been developed. These enable Morse code messages to be sent faster and with the minimum of effort. Nowadays with the decline in the use of Morse code by professional users, the main use for Morse code keys and Morse code keyers is within ham radio or amateur radio where Morse code still provides a very effective and efficient form of radio communication. Additionally there are many collectors of Morse code keys. This provides a fascinating insight into telegraph and radio communications of years gone by, and it can be an interesting hobby in its own right.