PXML No. 3
Approval No. BABT/PXML/3 DBS0014
The Navigator is a microprocessor controlled Key and Lamp Unit available in either 8+8 or
16+16 capacities. The central unit is wall-mounted and contains the power unit, processor,
interfaces, line filters and IDC terminating boards for exchange and terminal wiring. A
central unit supplied as an 8+8 system can be expanded to a 16+16 system by fitting
additional interfaces, line filter, expansion and IDC terminating boards. When an 8+8
system is expanded in this manner, all the existing terminals will normally require
replacing with 16+16 terminals.
The system supports Call hold, Call transfer, Conference and is programmable by
Note: Terminals are interchangeable, but an 8+8 terminal fitted on a 16+16 system will
only be able to access the first 8 lines and terminals.
From the 17 August 1990, Navigator will be supplied with new software, Version V4.2
offering the customer four additional features:-
- Answer Longest Waiting Call
- Conference Calls
- Ringing Detect Interval
- Timed Break Recall Interval programmable between 77.7mS up to 1,243mS.
A mains filter is included within the CCU to provide protection against mains borne
interference, a separate mains filter should therefore not be necessary under normal
Cabling of LJU's is carried out using cable equipment 6 wire 2503F which is terminated on
a LJU 2/3C or 3/3C. Navigator terminals either 8+8 or 16+16 are plugged into the LJU's,
the associated telephones (approved for connection to the Navigator system) being plugged
into the rear of the terminals.
Signalling can be either Loop Disconnect or MF which is determined by the associated
telephone. Recall from the CCU to the parent exchange can be either Earth-Loop or Timed
Break, programmed from terminal 1, default is Earth-Loop. Detection of incoming ringing
can be either Short (Auto Exch) or Long (Manual Exch), programmed from terminal 1, default
Made by GEC Ltd
Approved for direct connection to the PSTN (loop disconnect or MF signalling) or by
working as a (List A or D) subsidiary system (loop disconnect or MF signalling) connected
to a (List C) PBX.
The system is approved to provide either Earth Loop or Timed Break Recall.
Approved software levels for Navigator are:-
System Software V 1.18 or (IC
16 on main processor)
4.2 or later
Terminal Controller V 15.1 or later
(IC 7 on main processor & expansion board)
The system has a nominal power consumption of 80 watts.
There is no provision for standby power. In the event of a power failure each
exchange line is connected to one extension, line 1 is connected to extension 1, line 2 to
extension 2, etc.
In the event of a system having more exchange lines than extensions, those exchange lines
which do not have a corresponding extension cannot be accessed during power fail.
New units, either those supplied with the system or as maintenance spares, carry a 24
month warranty from the date of manufacture, shown as year and week on the self-adhesive
label fixed to each circuit board.
GEC ITEM CODE DESCRIPTION BT ITEM CODE
D143040/A 8 WAY CCU 870265
D143040/B 16 WAY CCU 870305
DPA1584/A MAIN PROCESSOR BOARD 870317
DPA1585/A EXPANSION BOARD 870267
DPA1583/A LINE INTERFACE BRD 870307
DPA1599/A LINE FILTER BOARD 870306
DPA1516/A TERMINATION FIELD BOARD 870266
D143044 POWER SUPPLY UNIT 870318
D143631 MAINS FILTER
D143026/ADA 8 WAY TERMINAL 870268
D143023/ADA 16 WAY TERMINAL 870269
RIBBON CABLE 1A 870324
RIBBON CABLE 2A 870325
Mains input (Time Lag) 72/3/15 314217
FS1 & 2 73/1 314179
FS3 73/4 314004
FS4 73/3.15 314024
FS5 73/0.2 665468
If using a headset, extensions specified by
the user can be programmed to automatically answer an incoming call after
a certain amount of rings, without having to press any
The volume of the ring tone can be altered to
suit individual requirements
Calls can be held so that the user can
answer another incoming call or make enquiries to other
Calls answered at one extension can be
transferred to another
Two extensions can speak to the same
Every exchange line has its own LED and
Every extension has its own LED and
The system allows the answering of incoming
calls in the event of a power cut
Note: Every Key and Lamp unit requires a
standard telephone plugged into it.
EXPANDING AN 8+8
If the original 8 x 8 system was installed with 8 x 8 NAVIGATOR terminals it will be necessary to replace them with the 16 x 16 terminal.
To test the NAVIGATOR system follow the points listed below:-
To expand it will be necessary to add the following hardware to the existing 8 x 8 CCU.
It will also be necessary to remove the radio frequency interference box lid to fit
BT ITEM CODE
||8 Way Termination Board
||Line Filter Board
||Line interface Boards
||Ribbon Cable 1A
||Ribbon Cable 2A
ALL LINE INTERFACE BOARDS MUST BE FITTED
Only line jack units -/3c are used with a maximum distance of 300 metres
(using 0.5mm cable). A functional earth is also fitted using 1.5mm cable.
The mains is fused at 3 amps.
System power consumption is 100 watts.
CCU TERMINATION BLOCK NUMBERING
Idle - Normal capacitance loop.
Seized - 220 ohms at 39 ma. This is an active termination and will measure different
resistance values at all other currents.
a. Navigator CCU has a Ringer Equivalence Number (REN) of 3.
b. Signalling limit CCU to Terminal. 50 ohms loop of a single pair i.e. about 300 metres
distance when using 0.5 mm cable.
c. Traffic carrying capacity. Non blocking system.
d. Transmission loss through CCU is zero dB.
e. Recall Signal Duration. (Timed Break 77.7mS [default] & Earth Loop
f. It must be noted that any wiring connection error to the Line Termination Boards or the
Line Jack Units can result in permanent damage within the CCU, terminals or both. Check
all the extension line connections before switching on the mains supply.
If block wiring or multiple cables are used for terminal distribution, a detailed record
should be left with the system identifying wiring connections.
Exchange line connections are not polarity sensitive.
g. A rechargeable Nickel Cadmium battery provides power to maintain the programmable
options during a mains fail situation. The battery is normally trickle-charged and has a
capacity to maintain the memory for up to 4 weeks.
The battery service life should be in excess of 5 years.
The mains on LED on front of filter still illuminates even if the input fuse is blown. The
fuse is 3.15A, slow blow.
-5v FS5 blowing. Problem likely to be 2+2 card (leaky capacitors). Each 2+2 card should
take approximately 40mA. Remove ALL 2+2 cards but one. Replace FS5 with a meter on ma
setting. Check current, if over 40mA replace the card. Check each 2+2 card in turn as
often more than one is faulty.
VERSION 1.22 SOFTWARE
Digit splitting when used with Venue 24 and 700 type telephones.
VERSION 1.18 & 1.20 SOFTWARE
Intermittent no incoming signal, when programmed for manual ring. Found to be 20 second
line-out period on manual ring programme. If an incoming call is answered and released
within 20 seconds and another incoming call is received within 20 seconds of the last call
being answered, the navigator will not respond to the ringing current.
Internal view of the Navigator 16