Also from the 1965 Pentex  publication

2. DOCUMENTATION.

2.1 Contractual Documentation. In addition to this specification the

following documents shall de·termine the Post Office requirements for manufacture

and supply purposes.

2.1.1 Unit 1.

ITEM DOCUMENT CONTENT ISSUE CONTROL SIZE PURPOSE

01 700801/S PTL Circuit Diagram 3A PTL,R A1 C,M

02 700801/W PTL Physical Layout 07 PTL,R A1 C,M

03 700801/U PTL Upt Layout 09 PTL,R A3 C,M

ISSUE: P = Provisional;

CONTROL: D = On file for distribution; R = Restricted; U = Unsuitable

SIZE: Ax = Isometric size; I = Imperial; M = Microfilmed

PURPOSE: C = P&S Contractual; S = Service; M =Manufacture; I = Information

Line 1-5 : for connection to subs telephone A, B and Meter - Do i need to connect anything to Meter wire ?

A Switch Outlet A-E : for connecting to B switches - ABPH, where P is meter H is signal for holding path through Crosspoint switch relays. - for my TXE2 I only have 1B switch and 2 subs cards - so how do i connect ?

MK1 - MK5 : Input : Mark signal for each subs line - connects KT(A) & KT(B) to 'marked' sub

KT- K Test: Output:  - enables call control to know state of line selected by MK signal above

• Free - 530 ohms to -48v ( 530 is 1.5k and 820 ohms in parallel) 

• Parked - 1.5k ohms to -48v

• Busy - earth ( when K relay is energised by P signal) 

PN -Output ? to A pattern relay - a -ve battery signal output is sent to the APR

N1 and NE are used to send a current pulse through the CNG field, to signal to the control circuits that Line 1 has gone off hook. 

N2 and NE are used to send a current pulse through the CNG field, to signal to the control circuits that Line 2 has gone off hook

N3 and NE signal line 3 has gone of hook

N4 and NE signal line 3 has gone of hook

N5 and NE signal line 3 has gone of hook

Operates the  MKR relay when pulled to