This is the standard British Post Office Telephone Set. It is a self-contained micro-telephone set with ringer housed in the case. Supplied complete with cords and moulded terminal block.

The micro-telephone incorporates the high quality receiver giving a gain of intelligibility equivalent to about 5db.

The set is constructed of moulded Bakelite and the standard colour is black.
An anti-side tone circuit is used so that extraneous noises in the vicinity of the listener cause minimum interference with the reception of speech.

Unless otherwise ordered Dial No. 4002-AG, showing numbers only on the number plate, will be supplied with these sets. Number plates with any other type of marking can be supplied if a sample or drawing is submitted.

The No. 4509-A set is similar but the dial is replaced by an apparatus blank. fitted at a later date if required.

Code No. Type Width Depth Height Weight
4509-A Manual 6" (5.24cm) 7.75" (19.68cm) 6" (5.24cm) 5lb 9oz
4509-B Auto 6" (5.24cm) 7.75" (19.68cm) 6" (5.24cm) 5lb 13oz
4509-C Manual 6" (5.24cm) 7.75" (19.68cm) 6" (5.24cm) 5lb 3oz
4509-D Auto 6" (5.24cm) 7.75" (19.68cm) 6" (5.24cm) 5lb 7oz
4509-J Auto 6" (5.24cm) 7.75" (19.68cm) 6" (5.24cm) 5lb 7oz

4509-A and B Sets are fitted with a Directory Tray.

4509-C, D and J Sets do not include a Directory Tray.

Taken from:-
STC Apparatus Catalogue for Telephone, Remote Control and Railway Signalling Catalogue, Edition 5 (1952)

These have also been seen with LP14226 & LP14230 (4509BG) markings

See also British Ericsson Telephone No. N1005A

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Last revised: February 02, 2019