Telephone Special Range (TSR)

Known within BT Sales as the Special Range Telephone (SRT) scheme, the phone was known by the engineering department as the Telephone Special Range (TSR).

Special Range Telephones were instruments of distinctive design and appearance which, in general, incurred higher tariff charges than the standard range of telephones.

Special Range Telephones continued the PO policy which requires that all telephone instruments having access to the public network must be owned, installed and maintained by the PO.  It did not alter in any way PO policy forbidding the attachment of privately owned telephones to the public Switched Telephone Network.

The customer paid a once only charge to have a Telephone Special Range (TSR) installed and then paid a quarterly instrument rental. The Post Office still owned the telephone although most customers, having paid the high once only charge, assumed that they owned the telephone.

Although of unusual and distinctive design outwardly, Special Range Telephones were compatible with both basic and premium range telephones and are capable of being used on exclusive or shared exchange lines, extension Plans 1A, Plan 4, and PBX extensions.

Originally, connection was by means of 5-way plug and jack (Plug, No. 505) and all SR telephones, except Plan 4 arrangements, were fitted with a locking cover to prevent accidental disconnection of service.  When the new style plug and sockets were introduced the Special Range Telephones were all fitted with the new plug.  If fitted with an old style plug then the telephone part number was 1XXX and if fitted with a new style plug the number would be 8XXX.

Special telephones may or may not incorporate a calling device (i.e. bell, Tonecaller etc), may or may not have a method of controlling, via a cut-off switch, the calling device and may or may not have a recall switch.

Each Special Range Telephone was given a type letter, as a suffix, which defined the field of use and whether it contained a calling device:-

Type A, contained a calling device, and was used on exclusive or shared exchange lines.  PBX extensions without a recall facility.  Main stations, but only if it has a bell or PO bell provided in addition and has no cut-off switch.

Type B, had no calling device, and was used on Plan extensions on Plan 1A, including Plan 4 off 1A.

Type C, had a calling device and recall button.  Was used on PBX extensions, where recall facilities are provided the telephone may only be a direct extension or the last station of an extension.

Type D, had no calling device, but had a recall button.  Was used on Plan 1A.

Special Range Telephones were not to be provided:-

  • with other than 700 type telephones.

  • at the main or intermediate instrument on an extension Plan 1A off a PBX extension, where recall facilities are required (1XXX only).

  • arrangements other than Plan 1A and 4 (1XXX only).

PLAN EXTENSIONS (only with 1XXX models)
When Special Range Telephones axe used as Plan 1A extension instruments, customers wishes regarding the provision of PO calling devices and/or PO cut-off switches should be complied with, and noted on the Advice Note.  These items, if requested, should be provided free of charge.

Then Special Range Telephones with integral calling devices are used as portable instruments on extension Plan 4, standard arrangements will apply.  According to the customers requirements, in the case of Special Range Telephones without calling devices, the second and subsequent jacks, subject to normal limitations, may be with or without PO bells; if associated they will normally not ring unless the telephone is plugged in but, exceptionally at the customers request, they may be arranged to ring regardless of whether the instrument is plugged into the associated jack or not.

Special Range Telephones were generally known by a their commercial name, which could include the supplier's name, e.g. STC Classic.  This commercial name was used by Sales Staff in the preparation of advice note statistics and in all contacts with customers.

Special Range Telephones will have the following information stamped on the underside of the base:-

  • PO type code - in a number range from 1000-1099 (PST versions 8000-8099) prefixed by, Telephone SR.

  • TYPE letter code, (following PO type code) of either A, B, C or D.

  • Year of manufacture - last 2 figures only.

  • Supplier's code - allocated by PO.

  • Country of origin - if not the UK.


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Last revised: August 06, 2022