PXML No. 83
APPROVAL No. 5/1000/2-3/C/020943
by GEC the Senator system came as a Mark 1 or Mark 2 system and both had
an ultimate configuration of 5+10. When the Merlin trading arm of BT
took over marketing of business systems, the Senator Mark 2 was
renamed as the
The Senator system case was wall mounted and had an integral
MDF. Adaptors could be supplied to cover 2 wire external extensions,
inter PBX circuits and extension bells. These adaptors would be wall
mounted along side the system box. A speed dialler called the
Autodial No. 5000
was introduced and this was a factory modified Tyne autodial.
The terminals used are the same ones used on the Ambassador system but
memory type (Telephone No. 8550) was not sold as a Senator
terminal. These telephones are connected by four wires to the CCU and are
connected via PST sockets. The style of telephone was changed in the
mid to late eighties, away from the generic Ambassador telephone style.
The later Ambassador/Senator system telephone is shown on the lower right.
POT phones with Earth Recall can be fitted via an External Extension Adapter
Senator cannot be used on PBX's which use "C" wire signalling or timed break
Power consumption - 200 watts.
Sales Brochure - PH3266
Sales Brochure - PHME813
Sales Brochure - CP/MS271
See also the Ambassador
Go to Ambassador/Senator telephones page
Extension Socket Wiring (secondary sockets only)
DPA1207A - Exchange line card (Blue handle).
DPA1209A - Extension Card (Yellow handle).
DPA1210A - LD Intercom Card to make system pulse dial (Off white handle).
DPA1217A - MF Intercom Card to make system tone dial (Grey handle).
Extension Adapter to allow connection of standard telephones.
- External Bell Adapter to allow connection of additional bells.
Senator ESS10253 - External extension adaptor
Senator with front cover removed
In the picture above:-
Grey handle = MF Intercom card
Blue handle = Exchange line card
Yellow handle = Extension card
CPU Card Codes
MF cards have the code 80
LD cards have the code 77/A
Fuses used on this system are BT types:- 36A/0.05, 72/0.5, 72/5, 73/0.1 & 73/4.
INTER-PBX ADAPTOR (SA10254) USED ON SENATOR 1 SYSTEMS (JULY 1994)
A problem was highlighted when engineers were experiencing difficulty with
an inter PBX circuit which kept locking up between a Senator and a Pentara when
calls were extended over it. The problem did not exist prior to the adaptor
being changed due to a lightning strike. This was eventually cleared by changing
the Senator backplane, and therefore the software, to Senator 2.
The reason for this is that all adaptors (I/C 374225) now include an additional
circuit board (marked DPA1383) that replaces the original plug-in IC. This has
software that offers full DC5 signalling conditions when used with Senator 2
systems but is not to be used with Senator 1. Field staff should be aware of
this problem to ensure that Inter-PBX adaptors are not changed out
Courtesy of Yannick McCabe-Costa
Cards removed exposing the Backplane
MF Intercom card