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The TELEPHONE HANDSET
by Bob Estreich

Although the first telephones worked, they were uncomfortable to use.

Watson described using Bell's "gallows" telephone as like holding a packing case in your hand. More work had to be done on the ergonomics. This was limited in the United States by the size of the transmitters - they were so large that they had to be mounted on (or in) large wooden wall boxes. The widely used Blake transmitter needed a box of its own. Even the White Solid Back transmitter that replaced it was inconveniently large for a handset.

In spite of this, people saw the advantage of having the transmitter and receiver combined. As early as February 3, 1880, Robert G Brown received a U.S. Patent for an "Electric Speaking-Telephone" that was simply a handset. (1) In his claim, he stated "I do not broadly claim the combination in one instrument of two telephones so arranged that when one is applied to the mouth the other will be applied to the ear …as I am aware such subject-matter is not new". Brown's patent (at right) was for an arrangement of the receiver that allowed it to be adjusted to the user's head length, and a semi-pivoting transmitter whose angle would adjust somewhat to face the user's mouth. We have no information on who first suggested joining two instruments, but the concept was well known to Brown. He built some of his telephones for Western Union's Gold and Stock Exchange, for whom he worked. His invention was viewed with a total lack of interest so he went to France and became a General Engineer for Societe Generale des Telephones. They liked the handset idea and produced their first model in 1879. It was rather sensitive to vibration, but this helped reduce packing of the carbon granules so was not as much of a drawback as it seemed.

Brown was preceded by two British inventors, Charles McEvoy and G E Pritchett. Both received patents in 1877 for handsets. McEvoy described a Butterstamp receiver with a speaking tube attached to it that reached down in front of the user's mouth. The tube attached to another Bell transmitter at the telephone end. Pritchett described a rather modern-sounding handset in general terms, but since practical hardware did not exist at the time to build it his patent did not attract interest. (2)

This is a good time to examine the problems of handsets, as compared to the separate transmitter and receiver.

SIZE: The components of the time were bulky, but good engineering was reducing the size. Europe had the advantage of having many inventors and companies working on the problems, but in the U.S, because of the patent issues and the capital demands of an ever-growing telephone system, research funds were limited. French inventor Mercadier showed that a receiver could be scaled down to quite a small size, if some critical ratios such as diaphragm gap to magnet assembly were maintained. This allowed Ader, particularly, to develop a watchcase receiver that was quite efficient and small enough to use on a handset. The Hunnings, Berliner and Edison carbon transmitters, although ignored by Bell in the U.S., were developed into practical small transmitters in Europe. Even Berthon's carbon pencil transmitter was miniaturised to handset size.

SIDETONE: This is the effect caused when sound going into the transmitter is fed back into the receiver. It distorts the received sound, making it sound "tinny" and less clear. The effect was usually electrical, but the tubes in early handset were also a major cause of acoustic feedback which also generated sidetone. At worst the sound could then feed back into the transmitter, be regenerated back into the receiver, and generate a howling noise that made conversation impossible. By 1918 Western Electric had developed an anti-sidetone or "retardation" circuit to remove this problem.(3)

EFFICIENCY: Since the sound waves did not strike directly onto the diaphragm, in spite of the cup mouthpieces used on many handsets, the output from the transmitter was lower than the wall-mounted transmitters. Ralph Meyer (3) notes that Kellogg used a retardation circuit in its early phones, and this combined with the lower level of signal reduced the acoustic feedback in Kellogg's Grabaphone to make it a practical handset. The different lengths of the users' heads could also place the transmitter in a less-than-optimal position. Some companies experimented with variable length transmitters (as described in Brown's patent) to overcome this.

PACKING: Like the wall-mounted transmitters, handsets suffered when the carbon granules packed down to the bottom of the transmitter. In some cases they could fall away from the center electrode and interrupt the conversation. The movement of the head and the pickup and replacement of the handset usually kept the granules from packing, so this was not a major problem. Even so, Berthon Ader issued an instruction leaflet with their telephones to show users the best angle for the handset. In the late 1890s and early 1900s, Bell Telephone Manufacturing in Antwerp developed a small capsule transmitter that effectively removed the packing problem from its handsets. In spite of this, it was not introduced into the U.S.

In 1892 L M Ericssons in Sweden released their Model AC110 "
Skeletal" or "Eiffel Tower", featuring an efficient handset. A similar handset was released by Bell Telephone Manufacturing on their "Eiffel Tower" phone some years later, and handset telephones became a familiar sight in Europe. During World War 1, U.S. servicemen saw these telephones and christened them "French" phones, a name which is still inaccurately applied to handset phones by eBay sellers today.


Now let's look at some of the early handsets.

Berthon Ader

These looked something like Brown's pattern, but the flat steel handle was not magnetized. They did not follow Brown's "pivoting" transmitter. The large transmitter was a three-carbon-pencil model. The right angle shape of the handset meant the sound waves from the voice worked directly onto the diaphragm. The receiver was a conventional Ader watchcase model, and the whole handset was fairly rugged and efficient.

L M Ericsson

The success of Ericsson's 1890 handset depended on the reliable transmitter. This gave a compact well-balanced handset that worked particularly well, and had a style about it that many early handsets lacked. Poole (4) described the transmitter in detail. Ericsson broke the metal tube into two short pieces joined into an ebonite handle. This reduced acoustic feedback and sidetone. A pushbutton fitted to some handsets cut out the transmitter on noisy or faint lines. There were complaints in Britain that the transmitter was relatively insensitive, but this seems hard to justify as it was quite adequate on lines of over 30 miles in Australia. Possibly to overcome the problem, an improved transmitter was introduced progressively in models built after the First World War.

Kellogg Monophone

The Monophone, by Kellogg and many others, was mostly only seen in Europe. It was a response to outbreaks of tuberculosis, a fatal respiratory disease. The monophone design allowed the speaking trumpet to be sterilised safely. Similar styles of handset were built using Berliner transmitters, and they were particularly popular in France.

Acoustic feedback should have been a major problem with this design. In fact the Phonopore company did use such a device to generate a feedback howl for signaling. In use, however, this does not seem to have been a problem. This may be due to a French modification that had small slots cut into the trumpet near its base. This reduced the pressure on the diaphragm at high voice levels and cut acoustic feedback.


Bell Telephone Manufacturing Company, Antwerp.

BTMC had access to much new technology in Europe and so were able to produce some technically advanced phones. Their handset was made in polished aluminium, a new metal for telephones. Aluminium was less resonant than the usual brass or steel, and feedback does not seem to have been a problem. The handset grip was available in a plain style not unlike Ericsson's, or an ornate floral-patterned style.


The handset was issued in a number of styles over the years, but its strong point was that it had one of the first capsule transmitters. This proved less susceptible to sidetone and feedback.


Western Electric

In the United States the handset did not go unnoticed. WE engineers had experimented with the style since the 1890s, and some models went into very limited production. They seem to have managed to make every mistake that their European counterparts had already worked around, all-metal cases, one-piece tubes that maximized feedback and sidetone, and large bulky transmitters. The disadvantages of sidetone and acoustic feedback soon became apparent and production was eventually stopped on the instruction of J J Carty, the Chief Engineer. Although an anti-sidetone circuit was designed as early as 1918, handsets did not go back into production until the first E1 bakelite models appeared in 1927.(3). The No. 2 handset featured a built in switch attached to the suspension ring at the top. Taking the handset "off hook" released the switch, which was probably a better arrangement than the usual "press to talk" switches.

Kellogg Grabaphone

When Western Electric did not proceed with handsets, it was left to their competitor Kellogg to produce the first U.S. commercial production handset phone in 1905. Kellogg was selling telephone parts into Europe through agents, and were made aware of the handsets in use.

Their first handset was based initially on Ericsson parts and called a Microtelephone, but was soon redesigned and improved into a simpler, more rugged model. They called this handset the Grabaphone, and fitted it to many of their models.


Grabaphone-equipped telephones became adequate but popular performers. The Grabaphone, too, disappeared when bakelite handsets finally appeared.


Western Electric E1

This was WE's first bakelite handset, designed to house their new No. 395 transmitter. The receiver was the usual efficient watchcase design. They went to a lot of trouble over the handset, measuring average head sizes to get the best handset length. The anti-sidetone circuit designed to go with it was not yet ready but the bakelite handset moulding proved excellent at reducing acoustic feedback (and so sidetone).

The ungainly transmitter was actually an advantage as it put the diaphragm of the transmitter closer to the user's mouth for a better signal. It stayed in production until the late 1930s when the all-bakelite No. 302 telephone was introduced.

L M Ericsson 1001

In 1932 L M Ericssons started production of their first bakelite phone, the DBH1001. Initially it was made by their Norwegian subsidiary, Elektrisk Bureau, since it had been substantially designed by one of EB's engineers. It was a little more angular than the Western Electric E1 and used a more compact transmitter capsule. It became the basis for many European handsets in the bakelite era.


Siemens No. 162 Telephone

In 1924 the British Post Office and Siemens re-examined the handset as a basis for new telephones to replace their standard candlestick-style desk phones. Siemens developed a new telephone, christened the Neophone, in bakelite with a new handset. The transmitter and receiver were reliable capsules designed for long life and fast changeover. It was successful and customers became used to the convenience of handset telephones. It was widely exported and became the standard telephone for most British-influenced countries.

The 162 and its 1937 replacement, the 300 series, lasted successfully until the 1950s. The handset, now listed as the No. 164, was then replaced with a smoother, more rounded Ericsson handset which finally did away with the scooped mouthpiece and the strengthening ridge along the top of the handle.


References......

(1) United States Patent and Trademark Office, Patent No 224,138

(2) Povey P J and Earl R A J "Vintage Telephones of the World

(3) Meyer Ralph O. "Old Time Telephones Technology Restoration and Repair" TAB Books 1995

(4) Poole J. "The Practical Telephone Handbook" 5th Edition 1912

(5) London Times of 8th May 1929: "Hand Combination Telephones - An Improved Type" from "British Telephones” website http://www.britishtelephones.com/t200info.htm


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