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MORSE KEYS

by Ric Havyatt


The electric telegraph really came to life in 1844 with a telegraph line between Washington and Baltimore (USA), when the now-famous biblical quotation was sent "What hath God wrought". Equipment was necessarily fairly primitive, and the operating key consisted of a brass strip which had neither gap adjustment nor spring tensioner. It resembled that shown in figure 1, and, for want of a better name, was called a "Correspondent".

Development took place fairly quickly to the stage where the instrument was described as "a lever acting on a fulcrum" and all future keys utilised this principle. The early lever keys soon had gap adjustment, but the spring tension was set during manufacture and could not easily be changed. A key of this type is shown in figure 2, and is generally known as a "lever correspondent".

It was not until 1950 that adjustable coil springs were introduced to Morse keys, which then provided adjustments for both the contact gap and the lever tension, or pressure necessary to close the contacts.

Long spells of operation of Morse keys soon produced problems with the operators in the form of "telegrapher's paralysis" or "glass arm". We know this problem today as "repetitive strain injury" or "RSI". One remedy was to turn the key mechanism through 90o so that a side-to-side operation resulted instead of a vertical operation. Of course, operators were expected to operate at fast speeds to get through the maximum amount of traffic and this exacerbrated the glass arm conditionm.

To provide for easier operation and, at the same time to accommodate the requirements of increased speed, a type of vibrating key was introduced in 1880. This key had its problems and resulted in blurry sending, causing crack operators to say that it was "fit only for a bug" or that it was a "bug's key", the term "bug" being used in a derogatory sense to indicate a lousy operator.

Now we introduce Horace Martin who was granted a patent in 1904 for a semi-automatic key which later became known as the "Vibroplex" key. Vibroplex keys are still produced in the USA even though commercial Morse has been discontinued for several years. Martin's key produced dots automatically when the lever was pressed to one side and manually controlled dashes when the lever was pressed to the other side. The patent on this semi-automatic key prevented others from copying it but, of course, there were many attempts to side-step the patent. It is ironic that Martin chose to decorate the nameplate of his keys with a scarab beetle, which resulted in semi-automatic keys being called "bugs", a title so scathingly given to the earliest vibrating keys. Another more acceptable name for these keys is "gigger" which is a name for a mechanical device for which the correct name is not known.

In the early days of telegraphy in Australia, most telegraphic equipment was imported. In the 1920's several individuals and companies started to manufacture both the simple hand key (up and down movement) and the semi-automatic type (transverse movement). Probably the best known of these was Leo G. Cohen, a telegraphist working in Melbourne. His keys were sold under the brand "Simplex Auto" and were very popular with PMG telegraphists (figure 3). They are also highly regarded by amateur radio operators and can be heard on the amateur bands where Morse is still used.

A Sydney manufacturer was "Buzza Products" who produced both a hard key in an oval base (common American design) (figure 5) and a semi-automatic key. They had a factory in Whiting Street, Artarmon until fairly recent times.

A couple of manufacturers operated in South Australia, one producing a semi-automatic key known as "Automorse". It was unusual in that it had three levers, two of which were for the standard semi-automatic operation and the third was to produce automatic dashes. It was not really a success. The other South Australian manufacturer turned out a semi automatic key known as the "Pendograph" (figure 4). This had a vertical oscillating lever instead of the usual horizontal lever, although the paddle arrangement on it was similar to most other semi-automatic keys. Western Australia also had a manufacturer of Morse keys and there were several other minor manufacturers in different parts of the country.

Figures 3, 4 and 5 are of Australian made keys.

First published in the May 1992 edition of the ATCS Newsletter.