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A HISTORY OF THE TELEPHONE HANDSET | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Taken from the L. M. Ericsson Review, 1925, Volume 2 Notes of Interest concerning some of L. M. Ericsson's earlier Types of Telephone Equipment
It is our intention to collect what interesting facts may still be available covering some older types of construction and publish the same under the above heading, this present article being devoted to. The fundamental idea of joining together receiver and transmitter by means of a common handle originated with Messrs Anton Av'n and Leonard Lundqvist, former engineers in the employ of The General Telephony Company of Stockholm. The first experimental model was constructed by these gentlemen in 1884 and is still in existence. This very interesting model is shown pictured to the right and now forms a part of the historical collection of the Royal Telegraph Department, where it may be found under number 2556. The model is composed of a single spring contact transmitter and a horse-shoe magnet receiver of the type commonly manufactured by L. M. Ericsson at that time, attached together at a suitable distance from each other by means of an iron wire around which two pieces of wood - each of a semicircular section - are tied with string so as to form a handle; the whole of a very simple and primitive construction, but so typical of the micro-telephone that it has remained practically unchanged, even though the separate parts may have undergone important changes. The following letter from Mr. Lundquist may be of interest in connection with the origin of this model. He says "If I remember rightly, the idea was conceived while carrying on the work of adjusting the oldest type of single spring contact transmitters on the 50-line Ericsson switchboards with rigidly attached transmitters, this work being under my supervision for a number of years. Mr. Av'n, who was operating engineer at that time, took hold of the idea, after which a practical model was constructed in the Ericsson shops in 1885". Sincerely yours, L. Luiidqvist. Stockholm, 13th September 1922. Evidence to the effect that the year 1885 is correct is obtained from a letter dated April 10th, 1885, sent by L. M. E. & Co. to Mr. Victor Jacobsson in Norrkoping, Sweden, which reads in part as follows: "and for this purpose we suggest a micro-telephone, intended for use with our multiple switchboards and which consists of a receiver and transmitter rigidly united by means of a common handle, enabling the operator always to have the same at hand in whichever direction she may turn while working at her position. The price of such an instrument will be about 55 Swedish crowns. Its connection to the switchboard is very simple and may be accomplished in a very short time. Necessary instructions, for this purpose will be given when required". Yours faithfully, L. M. Ericsson & Co. by A. B - m. Thus the fundamental principle of joining together a receiver and transmitter by means of a common handle was evolved, after which the original model was handed over to L. M. Ericsson for manufacture. Another model, consisting of two receivers, was also made, this model being a prototype. The construction of the single spring contact transmitter, however, required its being held in a horizontal position while in use. This was accomplished by bending the tubular stems in obtuse angles, see 1886 model. In 185 model, the transmitter was placed so as to form an acute angle with the axis of the handle, this construction in later years being commented on by former shop superintendent C. J. Andersson as being: Av'n's idea of mounting the transmitter. Very few microtelephones were manufactured during the first years, as they were made chiefly for use with multiple switchboards, this being also clearly evident from the above quoted letter. Also their price - 55 Swedish crowns - was rather high compared with the monetary value at that time. As new types of transmitters were evolved, the construction of the micro-telephone was suitably altered. Thus, we have models with carbon pencil transmitters and transmitters with small carbon balls placed between carbon diaphragms, this latter being represented by the 1886 model. These types were all rather complicated, and it was not until the advent of the carbon granule transmitter that the manufacture of hand micro-telephones could be appreciably increased, thanks to the improved construction of the transmitter. This took place in 1888. Even this type (1889) was both heavy and cumbersome according to present-day ideas, however, chiefly on account of the long receiver with horse-shoe magnet. It was not until 1892 and 1893 that the outward appearance of the micro-telephone began to be more in conformity with that of the present-day type, both the transmitter and the receiver having been made appreciably smaller, the latter by the introduction of ring magnets. The evolution of the hand micro-telephone is well illustrated in the picture
below, in which the more important types are shown. We will here give a
short characterization of the various models.
1885 1886 1888 1892 1893 1893 1895 1898 1898 1898 1903 1907 1909 1920 1921 1928 The above sequence covers only the common hand micro-telephone for subscribers' sets and switchboards. In addition, the types 1909 to 1921 are made in a number of varying styles with or without battery switch, with hygienic mouth-piece, etc. A number of other types have also been constructed for special purposes, such as for military use, for mines and for divers. All in all, more than two million hand micro-telephones have been manufactured at L. M. Ericsson's Stockholm works. The following table gives the quota for each year, and also clearly shows the existing market conditions during the various years.
The micro-telephone soon earned a very deserved Popularity and is now being used in a majority of countries. In England, towards the end of the nineties, telephone instruments equipped with micro-telephones of Ericsson's manufacture were extensively used, and although the Post Office later on introduced other types, the hand micro-telephone has retained its popularity, and an increased tendency to return to the same has been apparent of late. A Condensed History It was the granular transmitter that made the handset a practical device. Early receivers were bulky and heavy and the transmitters were delicate and sometimes too large. Like the telephone it was not just one or two people who invented the handset. In 1877 Charles McEvoy and G. E. Pritchett, both acting independently, patented the handset. One handset used the butterstamp telephone with a speaking tube attached, whilst the other was drawn like a modern handset. The later was not possible at the time due to the size of components at the time. The first handset made was designed in the USA by R. G. Brown in 1978. What made this handset acceptable was that Brown turned the large receiver magnet sideways and it formed the handle, which is turn was joined to a microphone. He used the Edison carbon transmitter which did not like being moved around. The American companies did not like handsets and Brown moved to France where he and Ader devised transmitters and receivers. The handset followed and became popular with European telephone users. Whilst all sorts of transmitters were used, the carbon granule transmitter was the best of the bunch. Manufacturers tried for years to better this transmitter but never really succeeded. It suffered from granule packing which caused bad transmission or looseness of the granules which caused noise. Whilst the handset actually helped prevent the granules packing (because of constant movement) it actually worsened the noise issue. The moulded handset produced in 1928 was a game changer. It was cheap to produce and used the latest carbon granule transmitter. The transmitter was an insert and easily replaced. It was not until the late 1970's that miniaturisation of
electronic components made the manufacturer of an electronic transmitter a
possibility. |
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Last revised: October 07, 2020FM2 |
A
number of models of miscellaneous equipment, in many cases the only remaining
evidence of the types which they represent, have, during L. M. Ericsson's well
nigh 50-years existence gradually accumulated in the model collections of the
various factory departments.