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Old 17th Mar 2017, 10:38 pm   #23
Pellseinydd
Heptode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
Default Re: GPO Jack unit 1B

The PCB in the Jack Unit 1B is not the same circuit as the one in the Tele 746.

The board in the Jack Unit 1B is a 'Telephone Unit D93093; whereas that in the Tele 746 is a 'Telephone Unit D92732' - similar looking but not quite the same.

The D93093 is only used in the Tele 787 as far as I can see in addition to its use in the Jack Unit 1B.

One other thought - is the 'pendant' telephone actually a 'Telephone No 713' or is it the other version known as a 'Telephone N4455' ? They both look the same externally but the terminal arrangements are different as the N4455 has four sets of make before break contacts which would 'mess things up' if using the terminal arrangements of a Tele 713.
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