And now here are some special purpose telephones and apparatus.
A telephone issued to linesmen and installers. It worked as a normal telephone on automatic
and CB manual exchanges. In addition an internal battery allowed it to speak to and power
a standard telephone. A transistorised ringing generator made it possible to ring a
telephone to test the bell. I have prepared a facsimile of the
Installation and Operating Instructions in Adobe
Acrobat® format [70 kbyte download].
There is some debate about the origin of the title 'Buttinski'. However that's what
telephone engineers round the world call this type of phone. It is used in exchanges
to plug into equipment for test to monitor or butt in to calls. The plug has two
ends, one for selector test jacks and the other for linefinder jacks. The hook
switch is controlled by the red button on the handle which can be locked down
by twisting. In the off position it monitors the line without seizing the
equipment. The dial is fitted in the rear of the receiver mount.
A lineman's test telephone, Telephone No 284 was produced in three variants to the same basic specification. This is the version from A.P. Besson (now Hosiden-Besson. It has two switches on the back. The upper, is a 3-position switch - monitor the line without looping it, normal loop, transmitter cut-out. Dialling is switchable between decadic and DTMF by the lower switch. The front buttons are Recall, DIS to break the loop briefly, and POLarity indicator using the red and green LEDs at the top. The ringer uses the receiver as the transducer. Various cord options were available. This one is fitted with a standard telephone line plug.
A very handy diagnostic tool used in Strowger exchanges. The plug is inserted into a battery jack on the nearest rack. The white switch lever connects the Lamp Switchboard No 2 inside to either battery or earth. Pressing the tip of the metal probe onto the part of the circuit under investigation gives an indication of the voltage present.
Used for tracing cables. The Oscillator (right) can be connected to a cable pair or to one wire and earth to inject a tone signal. The amplifier feeds the received tone to the earphone when its probe is close to the traced cable. The amplifier can also be used with a search coil - not shown - and is stowed in the neat plastic case below. The earphone can also be plugged into the oscillator whereby a tone is heard when the pair being traced is short-circuited.
Head-band mounted lamp for use by technicians working in awkward poorly lit areas - especially at the back of Strowger racks. I really must get a better-looking model.
A magneto generator in its own separate case, might have been used with a small switchboard.
This unit was current from the 1930s and into the 1950s, when it was
superseded by the comparatively lightweight headset below. The microphone
was uncomfortably heavy and required the canvas strap around the neck to
support its weight. .
This one, being modelled by Leslie at Hitchin Camera Club, has lost its original plug, which was of such a heavy design that it could nearly pull you over if dropped accidentally. I now have a plug, but have not got round to fitting it yet.
Here is a picture of me modelling the later model of headset, the one-piece, lightweight Headset No 1. The transmitter inset, No 15, is designed for horn loading and the receiver is a smaller version of the one used in handset No 3 and is Receiver No 3T. The horn detaches for cleaning. The normal connector on the cord is the four-pole Plug 420 - much lighter than on the older headset.
Private
Post-Lib