TELEPHONE No. 246


P.O. ENGINEERING DEPT. 
ENGINEERING INSTRUCTIONS
TELEPHONES
STATIONS
A 3301
Issue 2, 25.1.63

PENDANT TELEPHONE - TELEPHONE No. 246, BLACK
Conditions of Use and Installation

1. Introduction
A pendant telephone is particularly suitable where it is desired to conserve desk or table space, and also where a subscriber desires the telephone to be fixed in an inconspicuous position. A separate mounting is available to carry the dial.
This Instruction describes the conditions of use and method of installation of the pendant telephone, and gives details of associated items. A description of the pendant telephone and associated apparatus is given in A 1301.

Pendant telephones are suitable for use on D.E.L.s, P.B.X. extensions and private circuits. Any press buttons required must be connected externally. Because of the limited facilities provided by separate buttons, and restrictions imposed by the circuit or its associated Bell-set No. 37, the Telephone No. 246 is, in general, unsuitable for use on extension plan installations, and requests for such applications should be dealt with locally on a non-standard basis.

2. Limitations of use
If a dial is required or might be required later, e.g. on conversion of an area to automatic working, the provision of a pendant telephone as a wall telephone should be discouraged and refused in all but exceptional cases, since the dialling unit is unsuitable for wall fixing. The pendant telephone itself, without dialling unit, can be fitted as a wall telephone at non-dialling stations in lifts, stock exchanges, hotel bedrooms, etc. where the standard type of telephone is unsuitable.

3. Equipment required
The Telephone No. 246, Black is used with Bell-set No. 37 and Mounting, Dial, Automatic, No. 19, Black in C.B. and automatic areas, and with Bell-set No. 31, Black in L.B. areas. A Generator No. 26AN is required in magneto areas.

4. Brackets, Mounting
One or both of the following angle brackets should be requisitioned separately if direct fixing of the telephone or dialling unit in a recess of a desk or table is unsuitable (see par. 9).

  1. Bracket, Mounting, BU (includes all screws for the Telephone No. 246, Black and desk fixings).
  2. Bracket, Mounting, BY (includes all screws for the Mounting, Dial, Automatic, No. 19, Black and desk fixings).

5. Installation
The pendant telephone is particularly suitable for fitting in knee-hole type desks. It should be fitted in a handy but inconspicuous position with the handset (Telephone No. 164) suspended in a vertical position. The appropriate bell-set is always fitted separately.

6. Dial mounting
The dial mounting (for automatic areas) is fitted under the desk or table edge, so that the dial and slide can be drawn out and replaced after use.

7. Base plate
The base plate of the pendant telephone has a two-hole fixing to the desk or table and the gravity-switch case is held to the base plate by two trapped screws. The lower screw must never be left loose, as the projecting head of this screw would foul the mouthpiece and prevent the handset being removed easily from the gravity switch.

8. Cord outlets
Separate cord outlets are provided for each cord connected to the pendant telephone. They are interchangeable to suit the selected position in which the telephone is to be fitted.

9. Alternative mountings for telephone and dial
As the fitter cannot determine the actual method of fixing until the subscriber has been consulted and the location of the telephone, etc. agreed, a Bracket, Mounting, BU for each telephone and a Bracket, Mounting, BY for each Mounting, Dial, Automatic, No. 19, Black should be issued to the fitter. This procedure will obviate delay in completion of the installation work. Where direct fixing is possible, care should be exercised to see that the return of the surplus brackets is accounted for on completion of the Advice Note.


P.O. ENGINEERING DEPT.
ENGINEERING INSTRUCTIONS
TELEPHONES
STATIONS
A 1301
Issue 1, 19.5.39

SUBSCRIBERS’ APPARATUS - PENDANT TELEPHONE
Description

1. Scope of Instruction
This Instruction describes an instrument of the H.M.T. type, which is known as the ‘Pendant’ telephone. This instrument is particularly suitable for use where it is desired to conserve desk or table space and where a subscriber desires the telephone to be fitted in an inconspicuous position. The Rate Book title is “Telephone No. 246, Black” and it is used in conjunction with a “Bell-set No. 37” (in auto. and C.B. areas) or “Bell-set No. 31” and “Generator No. 4CN” if necessary (in L.B. areas). When used in an auto. area, a dialling unit, consisting of a dial and “Mounting, Dial, Auto., No. 16” is provided. Mounting brackets are provided to permit the telephone and dialling unit to be fitted in the most convenient position on a desk or table ; details of these fittings are given in the relevant paragraph in this Instruction. The policy adopted for provision of this telephone, and installation instructions, are given in A 3301.

2. The ‘Pendant’ telephone
Rate Book components
The instrument, which at present is supplied in black only, includes the following parts:-

Hand-set and extensible cord - Telephone No. 164 Black with Cord 3/1, 21 in. (Ordinary H.M.T. with “Cord, Instrument, Extensible, 3/1, Brown, 21 in.”)
Terminal Block - Block, Terminal, No. 20/8, Black.
Terminal block cord - Cord, Instrument, 8/09E, Black, 9 in.

3. Description
The body is secured to the back plate by two trapped securing-screws. The body of the telephone incorporates only a terminal block (to which the instrument cord and the cord incoming from the terminal block are connected) and gravity-switch spring-set, the latter having been designed to reduce the possibility of the gravity-switch sticking. Twin contacts are employed in the spring-set, which has been arranged so as to be easily accessible to facilitate adjustment.

4. Cords
The positions in the telephone at which the extensible cord and terminal block cord are led out are reversible, so that the hand-set cord may leave at the side of the telephone nearest to the user in any particular installation. Rubber sleeves are fitted at the cord entries to the telephone case and handset, to reduce faults especially in the hand-set cord. The rubber sleeve at the hand-set end of the extensible cord is supplied with the cord, whereas those at the telephone cord entries are not.

5. Fixings of Telephone and Terminal Block
The instrument is provided with two countersunk holes in the back-plate for fixing with No. 8 by 1 in. Csk. hd. wood screws, 3/16 in. of the length of these being occupied by the back-plate. The terminal block associated with the telephone is provided with 2  x No. 6 by 1 in. Csk. hd. wood screws, 1/2 in. of their length being occupied by the block.

6. Dialling Unit ”Mounting, Dial, Automatic, No. 16.”
This dial unit holds the dial and has a Bakelite dust cover which is secured by a metal ring. The dialling unit includes the following parts:-
“Cord, Instrument, 5/2911, Brown, 18 in.”
“Block, Terminal, No. 20/8, Black”
“Dial, Auto., SS No. 10
The dial should be requisitioned separately.

The support for the dial is a bakelite moulding, the special long securing-screw for the dial being accessible from the front. The metal slide has felt guides for smooth action, and bakelite fastenings are provided on both the slide and mounting to secure the cord which connects the dial to the terminal block. This cord is similar in type to those used on switchboards, to allow great flexibility, and is connected directly between the dial and terminal block. The mounting and slide can be separated by removing the cross bar.

7. Fixing's for the Dialling Unit and Terminal Block
The slide is secured under a desk top by three No. 8 by 3/4 in. Rd. Hd. wood screws, 1/8 in. of the length of these being occupied by the mounting; the terminal block has two No. 6 by 1 in. Csk. Hd. wood screws supplied, 1/2 in. of their length being occupied by the block.

8. Brackets (for telephone)
”Bracket, Mounting, BU “ is an enamelled sheet-metal right-angled bracket which may be used to allow a more convenient fixing for the telephone (see A 3301).  Three pairs of tapped holes for securing the telephone are provided so that the installation occupies the minimum amount of space conveniently possible. Three No. 8 by 5/8 in. Csk. Hd. wood screws and two 2 BA by 5/16 in. Csk. Hd. screws are supplied with the bracket for fixing and securing the telephone, respectively, in any of the three positions available; 1/8 in. of the length of the wood screws is occupied by the bracket.

9. For dial-mounting
“Bracket, Mounting, BY” is an enamelled sheet-metal right-angled bracket, and is used to support the “Mounting, Dial, Automatic, No. 16” when fitted to an uneven surface under a desk top (see A 3301).  Twelve countersunk fixing-screw holes are provided, as shown in the figure, so that the most convenient fixing may be made. Six No. 8 by 5/8 in. Csk. Hd. wood screws and three No. 2 BA by 3/16 in. Ch. Hd. screws are supplied with the bracket for fixing and securing the mounting, respectively, as described above; 1/8 in. of the length of the wood screws is occupied by the bracket.

10. Diagrams
Details of the telephone and circuit arrangement diagrams are given in A 3301, and a circuit diagram of the telephone is also pasted on the inside of the back plate of the instrument.

Circuit diagram N346.

Click here for the circuit diagram - Web users - CD users.

Diagram - N4299 for Direct Exchange Line, Auto connections.

Additional good quality pictures

General information on 200 type telephones

Collectors Information - what to look for

How to wire the Telephone No. 246 to the Bellset No. 37 to make it work on BT Plug and Sockets

How to restore Bakelite

Dismantling the Handset

 

 

 
 
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Last revised: January 19, 2013

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