Tuesday, May 4, 2010

Linesman Telephone - TMC 1705

I think this Linesman phone belong to RTM (Radio TV Malaysia) serviceman or engineer (since it got RTM mark on the top of the cover). It is a nice rotary type linesman phone for your display cabinet or collection


The Linesman’s telephone is a portable instrument, suitable for connexion to all
types of exchange line and designed for use by maintenance and field
A three-position slider switch enables the internal battery to be switched in and
out of circuit and in the non-locking position of this switch, connects ringing
current from the transistorised generator to the line terminals. A jack is provided
so that a headset (Pye TMC Headset S 508640) Cat.No. A437 can be plugged in
and used as an alternative to the handset and two sockets enable the output
from a tone amplifier to be connected to this receiver.
A polyurethane-impregnated nylon carrying case (Pye TMC Cat: No. A424) may
also be used to give additional protection in use in very rugged conditions.
1. Batteries. Three dry cells U2, R20 or equivalent (fully sealed types only)
should be used . Unscrew the cap on the side of the instrument and insert
the batteries ensuring they are correctly in series, outer end positive (+ ve).
Make periodic checks to make sure that cells are in good condition and not
2. Connection to Line: When the telephone is connected to a pair in a cable
that contains working circuits, disturbance to that circuit can be limited as
a) Set the three-position slider switch in the C.B. position and connect
telephone to line.
b) 704 telephone. Isolate the transmitter before removing handset from its
cradle by pressing the button on the handset. 1705 telephone. It is not
necessary to press the handset button to isolate the transmitter as this
model has a press to speak action.
c) Check that the line is not in use.
1 . Central Battery and Automatic Working
a) Check as in paragraph above that the line is not in use.
b) If line is not in use, release or press transmitter button as appropriate.
c) Dial the required number or make request to operator if on CB
exchange line.
d) When headset is used, replace the handset in its cradle after the
number has been dialled. To clear the line, remove the headset plug
from socket.

2 . Local Battery Working
When communication is required between two telephones proceed as follows:-
a) Set the three-position slider switch to the LB position; the internal
battery is now in circuit.
b) Connect the telephone to the line.
c) Push the slider switch to the ‘RING’ position to call the other station. A
tone will be heard in the receiver.
d) Arrange with the other party which battery is to be in circuit as it is only
necessary for one internal battery to be in use, therefore one telephone
should have the slider switch in the LB (battery in circuit) position and
the other telephone should be switched to the CB (battery out of circuit)
e) To conserve battery and receive incoming calls always replace handset
or remove headset plug from socket.
3 . Tone Amplifier
A tone amplifier may be used to identify cable pairs. The tone can be heard in
the telephone headset if the output of the amplifier is connected to the sockets in
the linesmans telephone.

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