A HISTORY OF THE TELEPHONE HANDSET
 


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


A survey of the various stages of development through which the products of a concern have passed and of how the different models have sought to meet varying conditions and requirements cannot fail to command a certain amount of historical interest.

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.

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 Avén 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. Avén, 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: Avén'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
Hand micro-telephone with single spring contact transmitter.  Horse-shoe magnet receiver, stem bent in an obtuse angle.  Suspension eyelet and exposed terminal screws for cord connection.

1885
Hand micro-telephone with single spring contact transmitter forming acute angle with handle.  Horse-shoe magnet receiver, exposed terminal screws for cord connection.  Made with both one and two battery switches in handle.

1886
Hand micro-telephone with carbon pencil transmitter containing three carbon pencils.  Horse-shoe magnet receiver, exposed terminal screws for cord connection.  This type was also made with carbon balls between two carbon diaphragms.

1888
Hand micro-telephone with carbon granule transmitter at right angles with the handle, large brass transmitter case, ferrotype diaphragm with flat platinum plate, ridged and drilled carbon block.  Horse-shoe magnet receiver, exposed terminal screws for cord connection.

1892
Hand micro-telephone with carbon granule transmitter, heavy transmitter case of aluminium, ferrotype diaphragm with flat gold plate, ridged and drilled carbon block, flannel ring and flannel cylinder with spiral spring.  Ring magnet receiver and exposed terminal screws for cord connection.

1893
Hand micro-telephone with carbon granule transmitter, heavy transmitter case of aluminium, ferrotype diaphragm with cupped gold plate, ridged and drilled carbon block, flannel ring and flannel cylinder.  Protecting diaphragm of varnished silk gauze with the word: "Patent".  Ring magnet receiver, partially protected cord terminals.

1893
Hand micro-telephone with carbon granule transmitter, heavy transmitter case of brass, ferrotype diaphragm with cupped gold plate, ridged and drilled carbon block, flannel ring and flannel cylinder.  Protecting diaphragm of varnished silk gauze with the word: "Patent".  Ring magnet receiver, partially protected cord terminals.

1895
Hand micro-telephone with carbon granule transmitter, heavy transmitter case of brass, ferrotype diaphragm with flat gold plate with lab, ridged carbon block (without holes), felt ring and one felt cylinder, six-pointed star shaped copper spring.  Protecting diaphragm of varnished silk gauze, the words:
"Made in Sweden by L. M. Ericsson & Co., Stockholm. Patented Oct. 29, 1895", stamped on the outside of the transmitter case.  Ring magnet receiver, partially protected cord terminals.

1898
Hand micro-telephone with carbon granule transmitter, light transmitter case of brass, ferrotype diaphragm with flat gold plate and anchor plate, ridged carbon block without holes, felt ring and felt cylinder, protection of brass wire netting.  Ring magnet receiver, partially protected cord terminals.

1898
Hand micro-telephone with carbon granule transmitter, light transmitter case of aluminium, carbon diaphragm with three notches, smooth carbon block, felt ring and 1+ 6 felt cylinders, protection of varnished silk gauze and brass wire netting.  Ring magnet receiver, partially protected cord terminals.

1898
Hand micro-telephone with carbon granule diaphragm, light transmitter case of brass, carbon diaphragm, smooth carbon block, felt ring and 1 + 6 felt cylinders, protection of varnished silk gauze and brass wire netting.  Ring magnet receiver, partially protected cord terminals.

1903
Hand micro-telephone with watertight carbon granule transmitter, light transmitter case of brass, carbon diaphragm with locking ring, grooved carbon block, star felt ring and two star springs.  Protecting diaphragm of tinfoil. Ring magnet receiver, partially protected cord terminals.

1907
Hand micro-telephone with adjustable handle, transmitter same as for the 1908 model.  Ring magnet receiver, partially protected cord terminals.

1909
Hand micro-telephone with capsule transmitter, removable capsule.  Ring magnet receiver, inside cord connections.

1920
Hand micro-telephone with water-tight capsule transmitter.  Ring magnet receiver, inside cord connections.

1921
Hand micro-telephone with water-tight capsule transmitter, similar to the 1920 model, spring-group switch in handle with several different connecting possibilities.  Ring magnet receiver, inside cord connections with terminal block for clustered connections.

1928
Bakelite moulded handset, with double pole receiver and carbon granule insert transmitter.  Jointly researched by Siemens Brothers and the UK GPO.

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.

Year Number of hand micro-telephones Year Number of hand micro-telephones
1885 to 1890 Only a very few 1907 80,201
1891 193 1908 44,952
1892 1,037 1909 43,842
1893 3,017 1910 68,322
1894 6,175 1911 69,251
1895 9,279 1912 76,277
1896 21,661 1913 86,880
1897 27,977 1914 64,224
1898 52,180 1915 83,485
1899 51,442 1916 117,574
1900 54,749 1917 127,293
1901 45,632 1918 79,069
1902 67,872 1919 69,904
1903 60,355 1920 67,965
1904 77,460 1921 72,682
1905 83,489 1922 26,883
1906 86,210 1923 37,257
    1924 53,387

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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