COMPACTS and GECOPHONES | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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These telephones were called different names, were produced in different models, had different model numbers and were made by a number of manufactures. In many instances the telephones had no model identification markings on them, but Ericsson always have a number of the base, whilst GEC and TMC generally had none. They are sometimes called "compacts" but GEC called their model the "Gecophone" and many people call them all "Gecophones", no matter who made them! There may also be a circuit diagram inside the telephone but the number on the diagram is not the model number, unless it is a TMC produced telephone. GEC produced a number of variants but these were mostly standard telephones. Ericsson, on the other hand, decided to adopt the compact case for many diverse models which included standard sets but also call and reply, battery, sub-master and railway variants. Three manufacturers made almost identical "pyramid" style compact telephones: Ericsson, GEC and TMC (TMC made telephones for Telephone Rentals [TR]). The actual pyramid-shaped body mouldings may well have been made in the same factory; certainly early GEC Gecophone cases are more or less identical to early TMC cases, except that the GEC ones have GEC lettering inside the case. Ericsson bought some Bakelite mouldings from TMC, which is why many Ericsson clones of the Gecophone have cradles marked TE. The Ericsson case was deeper on the corners whilst the GEC version had straight lower edges. But some early Ericsson cases also had flat edges (picture from BPO archives dated 1931). The base plates of these telephones differed but early Ericsson clones of the Gecophone had base plates that shared some design features of the early TMC phones of this type. Ericsson clones of the Gecophone made during the late 1930's and WW2 sometimes used a base plate which was populated with a GEC early style ringer and an upright terminal board. The base plate, was however, shaped like an Ericsson base plate (with the sides cut in). These components may have an Ericsson 'N' part number painted on them but they were almost certainly made in Coventry by GEC. They also have an Ericsson diagram N19995 (dated 1935) pasted to the capacitor. The Ericsson compact was originally supplied with a BPO Dial No. 8 (rather than the Dial No. 10), but both GEC and Ericsson fitted Dials No. 10 with small dial centre labels on many phones. The handset was the standard BPO Telephone No.164 type but originally used an inset microphone of Ericsson's own design. Both manufacturers used Mazak (an aluminium alloy) castings for the combined terminal block and switch hook pin shaft on the early compacts, but these were soon made in Bakelite. Somehow the Ericsson designers found room for a full-size ringer and bell gongs within the moulding, which had radiused slots at the bottom to allow the sound to escape. The gongs are fitted at an upright angle to allow them to fit in the casing. In some later variants the bell gongs were mounted flat to the base. GEC used miniature curved bell gongs whilst TMC used barrel shaped bell gongs. Some people confuse these telephones with similar Gecophones but the differences are fairly apparent. The Ericsson model has a different case with deeper corners, to let out more sound from the ringer and the base plate did not reach the outside edges of the case. GEC cases had straight bottom edges to the case and a base plate that covered the complete base of the phone, whilst TMC generally used the Ericsson style case, moving to a straight edged case in the 1950's. The Ericsson case normally has one cord entry hole but two holes have been seen, whilst early GEC models have one cord entry hole with later models having a hole in the case and a semicircular opening between the case and the base for a cable entry ferrule. TMC had two cord entry holes horizontally next to each other.
For line cord termination the Ericsson telephones generally had a curve shaped Bakelite terminal block fixed to the base plate. GEC initially used a Paxolin plate, mounted vertically on upstands, positioned next to the bell ringer. Because the cords only entered the top body this arrangement made the telephone difficult to work, so in 1934 GEC updated their Gecophone by fitting a smaller bell ringer, which had enough space for the terminal plate to be positioned horizontally on top of the ringer. TMC connected directly onto the terminals fitted within the main case as the base plate was normally fully loaded with components. Ericsson also made telephones for Telephone Rentals (TR) and Telematic. Some of the TR phones used a 2 way handset cord with an Electro-Magnetic receiver, which meant there was no induction coil and the line was polarity conscious. These were probably the Ericsson N1010B model which has 18 sound holes in the base plate.
TMC did not make its own dials and bought their dials from STC (manufacturer code W) so the dial should be marked with a W. The capacitor should be marked TMC. Dials and components on Ericsson phones would normally have an N prefixed part number. The TMC later case is very similar to that of the GEC Gecophone (no cutaway along the lower edge) but with a proper "stag’s antlers" style cradle, rather than the stubby GEC design. The base plate will probably have no markings and painted black. They have a small square wire gauze grille about 2” x 1½", covering the slots that let the bell sound out. The Telephone Rentals variant they made will have a TR logo on the handset and probably a TR dial label. It appears that the same TMC ‘innards’ were used to refurbish older telephones as the chassis is also found labelled as a "Conversion Set for PAX instruments Code SS2597 TMC S55680". The induction coil is identical with the BPO No. 27. Surplus stocks of these assemblies were sold off by J Bull (Electrical) Ltd during the 1980s and to confuse people further, some have been fitted to Gecophone bodies as well. The Paster diagram found inside these telephones will be prefixed with an "S" for TMC, "N" for Ericsson and "KS" for GEC. Some GEC models have the letters DRG followed by numbers and these relate to drawing numbers. None of these numbers represent the model number except for TMC. Identification of the maker can be simple, with the model number being more difficult. Dating can be difficult, because unlike the GPO who dated and marked all their equipment, much of the privately provided equipment was poorly marked or even unmarked. Make and model can be found from the identifier table below and dates may be found on the capacitor, under the rim of the dial and on the transmitter. If no dates are evident then the model production dates can be helpful. Gents & Co. produced intercom telephones called "Interphones". These were based on Gecophone parts, mainly the case, base plate, handset and some components. The handsets on these telephones may have the manufacturers markings obliterated by grinding out - generally in a very rough manner. These telephones had a rotary switch or press buttons to call other extensions. GEC also supplied the Irish P&T with the Telephone No. 522 100D.
Compact Quick Identifier
Ericsson Ericsson produced a multitude of models and like GEC included tropicalised variants. Ericson tropicalised variants had the part number suffixed with the letter "T". The table below gives identifying features of all the known variants. Model and diagram numbers all start with the prefix N. The table below allows identification by the label number and if the diagram is not on the web site, then please enquire. Ericsson Quick Identifier
GEC Introduced circa 1931 GEC produced a standard Gecophone that had an old fashioned style ringer (which was a size reduced Bell No. 1A) and because of the ringers size the base plate terminal board was fitted, vertically, to the side of the ringer. A Capacitor was fitted to the base plate and the telephone case housed an Induction Coil. All the mouldings were Bakelite. There was one cable entry in the rear of the case and the base plate had two large holes to allow the sound of the bells to be heard at a greater volume. The telephone was normally supplied with a wooden terminal block on the end of the line cord. These have model number starting with the letter "K". In 1933 a model was produced that was called a "convertible telephone" which was a local battery telephone with a two winding Induction Coil and a dial blank plate. The capacitor was then fixed in place with a metal strap and the bell ringer much reduced in size. The base plate then had eight holes to allow the ringer to be heard. When exchanges changed over to the Automatic system these telephones could be converted by replacing the induction coil for an ASTIC version and installing a dial. These telephones can be easily identified as they have switch hook contact sets comprising of one make and one changeover, whilst most Gecophones have a contact set comprising of two make contact sets. GEC then update the original Gecophone in 1934. The main change being a superior Induction Coil which had enhanced ASTIC qualities, the capacitor was held in place with a strap, the bell ringer was reduced in size, the line cord now entered the phone via a ferrule in the base plate and the Bellset terminal board was positioned horizontally on above the bell ringer. The internal terminal block in the 1931 models was fitted to one side of the bell ringer and the line cord entered the phone via the upper casing which made working on an opened telephone difficult due to the cables restricting the movement of the upper case; repositioning of the terminal block made access significantly easier. The switch hook forks also changed from the "antler" style to a short stubby style, which GEC designed to be difficult to break. The 1934 set also had a small amount of tropicalisation introduced, this being a slotted terminal plate to prevent surface leakage and cords that have no absorbent textile coverings at the ends. These have model numbers, which are numbered only. The 1933 style of construction continued in production until 1956, with just a change after 1948 when Tropicalised variants were introduced. The model number at this point was then prefixed with the letters "ST".
In 1956 there is mention of the Gecophone K or Gecophone 1000, which used an identical case to the Gecophone. The internal circuit was redesigned to match that of the newly introduced "1000 Telephone" but also acquired the new modern curved handset, with no spittoon. A new Induction Coil was introduced and two cylindrical capacitors were fitted. There is no indication that any of these were sold or produced in any number, but the phones were allocated code numbers for standard and tropicalised models. The GEC pictures available here were probably field trial pictures and it is thought that this model was dropped in favour of the new desktop telephone, the "1000 Telephone". These telephones have model numbers prefixed with the letters "TEL". The next Gecophone model, called the "New Gecophone", was first produced in 1959 and was identical to the plastic telephone used in the UK by the GPO throughout the 1960's and 1970's. Some Gecophones have a DC bell and were usually installed on certain GEC PAX's. They also had no induction coil because these phones were fitted with an Electro-magnetic receiver, which was just connected in series with the transmitter. In this case the handset cord would only have two conductors, instead of the usual three. These telephones are also line polarity conscious. The Gecophone saw considerable use on private (PAX, not PABX) systems installed by Reliance Telephone Company (a GEC subsidiary) and in the public network of the Irish P&T and some Commonwealth countries. Examples also turn up with the branding 'Air Ministry' on the base. The ST1503 model has been seen with Reliance labels on the case. There may also be dates on the telephone components; sometimes the on the rear edge of the dial along with the figures "104". In most cases the capacitor on the base plate is the best place to find a date. The date is generally stamped at one end along with the manufacturer code and capacitor part number. Click here for more information on the GEC Gecophone. Click here for GEC Gecophone wiring diagrams, picture identification and conversion to UK plug & socket. Click here for the miniature GEC Gecophone Minor. Click here
for the RMS Queen Mary identifier page. Model Numbers Originally, GEC telephones were always numbered with a two, three or four digit number, prefixed by the letter K i.e. K7055. The K numbers continued until around 1933/1934 when the telephones and switchboards had their Catalogue numbers changed to figures only, that consisted of three or four digits i.e. 204A. Circa 1948 (Current Comments - Volume 3, Number 1 - 1948) the catalogue numbers changed to two letters followed by four numbers i.e. ST1301. On 1st June 1955, GEC adopted a new method of code/catalogue numbering their telephone range. The code consists of three groups of characters. Every code number started with TEL. But in 1956 the Gecophone was renamed the "Gecophone K" or "Gecophone 1000". This was an updated telephone and superseded all previous Gecophones. The only Gecophones available were then the TEL31G and TEL32G and whether these were produced in any number is open to debate. Gecophones supplied to the Irish P&T are labelled on the base plate as 'P&T 100D Mark 522'. The Mark number may be different depending on the type of Gecophone. There may even be a manufacturers code and date e.g. C37, which is GEC / 1937. The Handset may be inscribed 606. The GEC Model No. 75 was used by the Irish Post
Office, their model
P&T 100D Mark 522. Other known Marks are 513, 515 and 520,
but what the GEC model numbers are needs to be confirmed. GEC Quick Identifier
Click here if you have the Circuit Diagram number. GEC List of Gecophones
In place of the dial was either a dummy dial, a rotary selector or a press button unit, whilst on the side was a lever ring key. Click here for Gents telephones GENTS & Co. Quick Identifier
TMC Most models had all the components fitted to the base, the bell gongs were barrel shaped and the case had two cable entry holes (horizontal) in the rear. Under the outer rim of the dial there should be markings, one being the letter "W" (they never made dials and so always bought them from STC) and possibly a date. The marking "4004B", which is the TMC code for the dial, may also be present. Telephone Rental models base plates have also been found with a set of 9 holes in a circle under each gong, a case with extended corners, a 6 way terminal block on the base plate and a flexible cord connecting the base to the main body. These phones are most probably made with component parts purchased from Ericsson. Many of the TMC compacts found have a cylindrical capacitor. These were introduced in the UK circa 1947. TMC also produced telephones for TR - Click here to view TMC telephones. These telephones generally have no markings on the base but may have a diagram inside the case. Model and diagram numbers all start with an S prefix. Many compact telephones can be dated by means of the capacitors, but the TMC cylindrical and square capacitors will probably be undated. TMC Quick Identifier
The S19098 was made mainly Ericsson with some parts supplied by TMC. The unknown/TR compact is probably made from parts
supplied by Ericsson. Ericsson base plates had 18 sound holes in
the base plate and the plate stamping looks very similar to the Ericsson
base plate.
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This style of telephone originated circa 1931. This coincided
with the introduction of Bakelite as a flexible moulding material and the
Siemens Brothers company producing the pyramid style telephone, which the BPO
adopted.
All Ericsson models had proper "stag's
antler" cradles whereas GEC Gecophones only used this type until 1934,
when they changed to a stubby design, which is pictured to the right, and was supposed to be
virtually damage free. In 1948 the telephone was tropicalised and
the cradle, whilst retaining the stubby antlers, had a thickened neck,
which contained vents.
GEC tropicalised Gecophones
in 1948 had a new type
of contact springset fitted, with thicker insulation, at an angle
to the terminal strip (shown to the right), varnished Induction Coil,
fine mesh over the base
plate sound holes and an enlarged cradle "neck". The enlarged "neck"
ventilated the case and was also insect proof.