|INTRINSICALLY SAFE PORTABLE TELEPHONE
Certificates: T/TEL/80 (Methane), No. 67 (Pentane)
Primarily designed for testing purposes, this portable telephone may also be used as a temporary station.
It is intrinsically safe and suitable for use in the petroleum industry, and above or below ground in coal mines. A plug with cord (N109914) can be supplied for plugging the instrument into Telesocket N107636A.
The instrument is carried by means of a strong woven-fabric shoulder strap, and is well protected by the weatherproof metal casing against the rough usage to which this type of set is liable.
Components include a modem shock-proof plastic handset with press key and 3-way rubber-covered cord, a ringer, an 'alnico' generator with anti-spark winding, an anti-side-tone induction coil, a panel carrying three capacitors, Bakelite-mounted terminals for line and microtelephone connections, and two *dry or inert cells housed in a neoprene lined compartment. The components are specially finished to withstand adverse atmospheric conditions.
The generator handle is normally stowed vertically between projections on the lid, and is turned down at right-angles for use. It is held rigid in either position by a spring-loaded slide on the crank.
Above the generator are two line terminals, which have knurled captive screw tops. P.V.C. covered wire is used for the internal connections.
A facsimile of the wiring diagram shown, is affixed inside the bottom of the case which is fastened to the body by four screws.
Dry cells are always supplied with the telephone for orders in the U.K. Inert cells for telephones being exported are supplied only when requested. A plastic holder for two 1.5 volt torch batteries (Adaptor N84081) which fits into the battery compartment, can be supplied for use in emergency.
Taken from the Ericsson Catalogue No. 60
Last revised: April 04, 2022