Telephone No. 8401AR is an Ambassador range telephone providing LD, MF or mixed signalling facilities and the option of earth loop, timed break recall or C Wire signalling. The signalling and recalling modes are selected by internal links not accessible to the customer. As supplied the links are set to give DEL working, mixed signalling and earth loop recall. Mixed signalling provides the facility of originating a call in the LD mode and subsequently changing to the MF mode for the duration of the call by pressing the button making, the telephone suitable for slow speed MF data applications.

For C Wire signalling it is necessary to change the instrument line cord to a six way cord (Cord Connecting 6/524). Telephone 8401AR is suitable for table or wall mounted use, two keyhole slots are provided in the base to facilitate wall mounting without the use of brackets.

Incoming calls are signalled by a bell with adjustable volume control and off switch. Last number redial and secrecy (transmitter cut-off) facilities are also provided.

Made by Autophon Ltd

Telephone 8401 AR is approved as supplied.
Telephone 8401 AR may be used on PBXs approved for use with telephones in categories 1, 3, 5 & 7.

Telephone 8401AR has a Ringer Equivalence Number (REN) of 1. Telephone instruments (BT and non BT supplied) are required to be labelled with their REN so that users do not exceed the permitted maximum number of ringers in circuit. A telephone with a REN of 1 has a ringer performance comparable to that of a standard instrument (tele 8746), the total REN value of all ringers connected at any time at an installation must not exceed 4.

The REN does not guarantee compatibility between ringers of different technologies on the same installation.

Telephone 8401AR is supplied with a line cord terminated with a Plug 431A. When used on C Wire signalling systems the line cord should be changed to a Cord Connecting 6/524 terminated as shown below:-
The links situated under the line and handset cord cover plate on the base of the instrument should be set on installation to give the required facilities a shown below, these links are not customer accessible.

          Signalling Options    Socket     Pins      Socket     Pins

            MF                  PL4        2+3       PL6        2+3
            LD                  PL4        2+1       PL6        1+2
            Mixed               PL4        2+1       PL6        2+3

          Recall Options
            C Wire PBX          PL3        1+2       PL5        2+3
            Timed Break         PL3        4+5       PL5        2+3
          * Earth Loop          PL3        2+3       PL5        1+2

          * As supplied

Telephones 8401 AR will carry an 18 month CPE warranty from the date of manufacture as shown on the base of the instrument (year and week marking forming the first 4 digits of the 11 digit serial number).

Telephone 8401 AR each draws typically 24 micro Amps on-hook line current on a 50 volt line to retain stored number memory. This may give apparent 'Low Loop' line test conditions.

As with other modern press button telephones, the electronic keypad and transmission circuitry may appear to give High Resistance telephone loop test conditions.

The keypads of Telephones 8401 AR are line powered and required no external power supplies. Line current is drawn whilst the telephone is "on hook" to maintain stored number memory. The stored number memory will be cleared if the telephone is disconnected from line for longer than (typically) 10 minutes. There is no provision for memory retention batteries in Telephone 8401 AR.

Telephone 8401 AR is designed to incorporate good RFI immunity in the frequency range 50KHz to 200Mhz.

Telephone 8401 AR is suitable for use where customers need to access MF signalling data services (e.g. Voicebank and Message pager services) via Loop Disconnect pulsing network but may also be used to supersede existing Ambassador Telephones, where appropriate, when direct replacements are not available.

The timed break recall facility will work satisfactorily on 70 Volt System X Lines.

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Last revised: April 17, 2021