|GEC 711 Wall Mounting telephones
This new and attractive wall-mounting instrument is a fully tropicalised version of the standard wall instrument designed in conjunction with the British Post Office and is approved by the Council of Industrial Design;
the telephone also complies fully with the specifications of Messrs. Preece, Cardew and Rider. it uses the highly efficient circuit first introduced in the
G.E.C. 1000 telephone and since used in the G.E.C. 706 and
telephones. This ensures an equally good performance from the G.E.C. 711 and the same degree of versatility. It is intended to replace the
G.E.C. 706 and cradle adaptor that has been used successfully as a wall-mounting instrument pending the development of the
G.E.C. 711. All the usual variations of the table-type telephone are also available in the
G.E.C. 711 wall telephone, including:-
STANDARD SUBSCRIBERS TELEPHONE
This is an ideal complement to the G.E.C. 706 desk telephone, and can be supplied for both automatic and C.B. exchange working. An automatic volume regulator is available for use on short lines where the high efficiency of the circuit produces a signal loudness that may cause embarrassment.
Provision is made to mount up to four keys and two lamps in the telephone case to give extra circuit facilities. These include:-
- Shared service working.
- “Call Main” signalling when the instrument is used as an extension telephone for either internal or external working.
- “Call Main” and “call extension” signalling when the instrument is used as one of a pair of extension telephones for internal working only.
- Internal buzzer for use in paralleled instruments as a calling signal.
- Exchange recall and transfer facility.
- Executive right-of-way facility.
PLANS 105 AND 107 WORKING
A plinth, similar in design to that used with the G.E.C. 706 telephone, can be added to
the G.E.C. 711 telephone to provide all the facilities required for a switching station in Plan 105 and 107 working.
When wall-type extension telephones are required, a suitable version of the
G.E.C. 711 telephone can be supplied containing the full terminal field used in the
G.P.O. 706 telephone for plan working. The G.E.C. 706 and G.E.C. 711
telephones are fully compatible, e.g., desk-mounting telephones can operate to wall-mounting switching telephones and vice versa.
Full details of these systems are given in Catalogue Leaflet No. STL.17.
The number ring, as in the G.E.C. 706 telephone, is external to the dial and is completely independent of
it. This means that in ordinary operating conditions the characters can be read easily even under indifferent lighting conditions, and when the case is removed for maintenance the number ring is removed also and does not provide an obstruction.
The arrangement and type of characters can be varied to suit local requirements.
The G.E.C. 711 telephone, when mounted with special bracket provided, projects an overall distance of only
4.3 inches (11.1 cms) from the wall. This feature makes it very suitable for use in confined locations where there is no space to provide a table, but the graceful shape makes it suitable for use in any surroundings. The
G.E.C. 711 is available in black, dual grey, and ivory. When a user wishes to leave the telephone in the middle of a conversation, the handset can be parked on the left-hand tines without operating the cradle switch.
All components of the G.E.C. 711 telephone are mounted on the base plate and are easily accessible for maintenance. A concealed screw retains the case and maintenance may be carried out without removing the instrument from the wall.
Like the G.E.C. 706, the G.E.C. 711 shows an improvement in performance of 4-6db on receiving and 6db on sending compared with former types of telephone.
As a result of these performance improvements, the G.E.C. 711 will operate over a local line loop of 1120 ohms of
6.5 lb. cable (0.5 mm. conductor) with a performance equal to that of previous telephones operating over a local line
loop of 660 ohms; i.e., a local line may be extended by 70%. Alternatively, the G.E.C. 711
will operate over a length of 4 lb. cable (0.4 mm.) with a performance equal to that of a previous telephone operating over the same
length of 10 lb (0.6 mm) cable.
The handset has been designed to give not only the greatest comfort to the user, but also maximum efficiency from the transmitter. The shape ensures that when the receiver is held to the ear in the normal manner, the transmitter is naturally located in the most effective position. The handset is very light in weight and access to the receiver and transmitter inset capsules is gained simply by unscrewing the earpiece and mouthpiece.
The transmitter is of the immersed-electrode, carbon granule, capsule type. Its good frequency response and power output have been well proven in the past and have contributed notably to the high performance of previous telephones.
The receiver is of the rocking armature capsule type used in the G.E.C. 706 Telephone and has a very high electro-acoustic conversion ratio. Acoustic equalisation produces an improved frequency response. The light alloy diaphragm increases the ratio of effective area to effective mass. The magnet is stabilised during manufacture, so that it has optimum strength.
The whole improvement gained by use of this receiver is not needed on the receiving side. The induction coil designed for the
G.E.C. 706 telephone transfers some of the improvement to the sending side.
In effecting the transfer of gain from receiving to sending side, the highest practicable degree of sidetone suppression has been maintained. The circuit is designed to give maximum suppression of sidetone on reactive lines (i.e. cable pairs), since the vast majority of telephones are connected to
their exchanges by multi pair cable.
The G.E.C. 711 for use with automatic exchanges, is fitted with a new dial, which, whilst retaining the
well known and reliable action of the G.E.C. Trigger Dial, has been modernised to conform with the
G.E.C. 700 series of telephones. The finger plate is normally made of plastic and is in the same colour as the case of the instrument. When required, a stainless steel finger plate can be fitted. The standard dial operates at 10 pulses per second and has a break-to-make ratio of 2:1. Dials having other ratios can be fitted if required.
A light plastic cover fitted to the back of the dial, giving complete enclosure of the mechanism, is a standard arrangement for protection against dust.
Conversion from a manual to an automatic telephone merely necessitates the replacement of the dial dummy by the dial, fitting the number ring to the case, and connecting the wiring already included in the telephone to the dial.
The ringer includes a new light-weight ceramic magnet and the coil has a resistance of 1000 ohms with an impedance of
17,000 ohms at 1000 c/s. It responds to alternating ringing current from hand or automatic ringing machines. Coils of higher impedance for multi-party working are fitted when required.
The cradle switch has been designed to eliminate any likelihood of sticking plungers. A new type of springset is fitted which still retains the twin contact effect, but gives more control over the adjustment and tensioning of the springs. A transparent plastic cover is fitted over the springs
to prevent dust accumulating on the contacts.
Owing to the high efficiency of the G.E.C. 711, some subscribers on short lines might be embarrassed by the excessive volume. The fitting of a 150-ohm resistor (G.E.C. code RDE3I5OR) across terminals 1 and 10 will reduce both sidetone and reception. Alternatively, this can be overcome by the fitting of a fully automatic volume regulator, which is easily wired in when required. This regulator limits sensitivity on short lines but restores full efficiency on long
lines. The G.E.C. 711 can be supplied either with or without the regulator. If required, the regulators may be
The G.E.C. 711 is designed and fully tested for service in all climatic conditions experienced in countries throughout the world. Special insulation is included, as well as adequate ventilation and protection against
The handset is connected to the instrument by a P.V.C. covered coiled cord. This is supplied in colour to match
The G.E.C. 711 can be supplied in the following colours:-
All mouldings are in modern plastic materials having a high degree of colour fastness (thus ensuring good colour matching when replacing parts) and good impact
Characters to appear on number ring are numbered:- 0 9 . . . . . . . 1 Clockwise.
G.E.C. 711 telephone
||Automatic wall model
G.E.C. 711 telephone
|| C. B. wall model
Taken from the GEC Leaflet STL 18A
See also GEC711 and the GPO
Telephone No. 711
Click here for prototype pictures