TELEPHONE No. 258


Field trial of lightweight headsets

General
This
specification provides for n field trial at Huddersfield and Chester of a lightweight headset coded "Telephone No. 258".  The telephone is fitted with a lightweight plug -''Plug No. 418"; the associated card has tinsel conductors, nylon braiding and is coded "Cord Instrument No. 4/72L Black 42".

OBJECTS
The main object of this trial is to ascertain the physical and electrical reliability of the new headset and its associated plug and cord, and to obtain fault data far comparison with the present standard headset.

Trial
50% of operators were initially given these headsets to trial for a month and then the headsets were transferred to the remaining 50% of operators for a month.  This interchange continued until the end of the trial.

Stores required

  Huddersfield Chester
TELEPHONE NO. 258 85 85
CORD INSTRUMENT 4/72L BLACK WITH PLUG NO. 418 20 20
PART I/DPI/695 MODIFIED 52 48

Specification No. TP 178

Dated October 1955

This headset was made by STC and came to be called the Headset No. 1.

 
 
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Last revised: November 18, 2020

FM