TELEPHONES TX65, 66, 68 & 69

TX65 TX66
TX68 TX69

Slimline terminals titled TX65 to TX69 are intended for use on new Pentara+Plus Phone Systems. It was originally planned to introduce a Headset module TX67 to complement this range, but due to the cost of this unit, it the module was never introduced into BT's portfolio.

The 'Slimline' terminals TX65 and TX66 are approved for connection to all Herald and Pentara systems, and the TX68 for B8, C and C+ systems onwards. Slimline terminals were not to be offered to extend the existing range of Herald or Pentara systems until stocks of the previous range of TX terminals were exhausted, unless being provided as part of an upgrade package.

The Slimline terminals are processor controlled and use electronic speech circuits in conjunction with specialised handset transducers, therefore it is not possible to fit or use any of the facility handsets available.

All Slimline terminals have continuously variable volume controls for the loudspeaker and tone sounder for use by the customer. A slotted screw, accessible through a hole in the base of the instrument enables the pitch of the tone sounder to be changed. This facility is not mentioned in the terminal user guide and generally will not require adjustment. Should it be necessary to alter the pitch, care by the customer or engineer making the adjustment should be exercised so as not to damage the control.

Unlike previous Herald/Pentara terminals, none of the new slimline terminals have any Power Failure working capability for incoming or outgoing service, therefore they MUST NOT be connected as a power fail extensions.

Full power fail facilities can only be provided by a Power Fail terminal TX52 3/SA20014 Stone (IC 37 5236) or 2-wire telephones. Incoming only service can be provided by any of the earlier terminals.

TX65 - Standard Slimline 4-wire Terminal with Monitor.
An eight programmable button Systemphone with Monitor amplifier which will replace the TX55. In addition to the eight programmable facility buttons. it has dedicated Hold, Program, Transmit and Recall buttons. The Monitor facility is usually provided on button 1, lowest key on the right hand row.

TX66 - Standard Slimline 4-wire Loudspeech Terminal.
As per the TX65 above, but with the addition of a Loudspeech, Handsfree facility turned on and off by the use of the "Monitor" button, i.e. button number 1. The facility buttons are identical to the TX65 with the addition of a latching Microphone Mute Button for use when used in the LST mode.

TX67 - Headset Module.
Not available.

TX68 - Large Slimline Terminal with loudspeech and Display.
A sixteen programmable button Systemphone with loudspeech and display. The new terminal will replace the TX54 (Operators Terminal), TX57 and TX58. In addition to the sixteen programmable facility buttons, it has dedicated Hold, Program, Transmit, Recall, Latching Microphone Mute (LST mic) and Monitor/LST (button 1 unmarked) buttons. See ADDITIONAL INFORMATION.

TX69 Add-On Key Module.
The TX69 can only be used on Pentara+Plus systems fitted with Software Version V10.1 or later. The add-on module has 24 programmable keys and associated LED's and may be attached to any of the TX6x terminals above. Up to three modules may be joined in tandem giving a terminal user access to an additional 72 programmable keys.

The extension card ports allocated to the TX69 must be physically consecutive from the 'host' terminal and reside on the same interface card.

Made by Philips TMC Limited.

Approval Number S/1000/GF/1981/PR

TX65 to TX69 terminals have no power fail working capability and must not be connected as power fail extensions. The use of a Master LJU connected in parallel with the speech pair of the terminal secondary LJU to provide temporary service with a 2-wire telephone is not permitted. The PXML requires that in the event of a total power failure a minimum of 20% of the exchange lines must be connected via exchange line cards SA20008 or SA20558 to suitable 4-wire terminals or to 2-wire telephones. At least one of these terminals or telephones must be capable of making an outgoing call during a power failure, i.e. the signalling mode of the instrument (loop disconnect or MF4) must be compatible with that of the parent exchange.

All Herald/Pentara terminals are intended for installation and use in a normal commercial environment. (Class A)

Terminals TX65 to TX68 are not suitable for power fail working and must NOT be connected as power extensions.

TX69 modules are allocated a 'Port' on a 4-Port Extension Display Card ASU 1A1/SA20557. Only the data pair is used, therefore up to 3 Key modules may be connected in a single 6-wire cable as shown below. The cable is connected to the data pairs at the Box Connection and wired out to a LJU 4/3A (Double Secondary). The extension card port/s allocated to the TX69/s must be consecutive from the host terminal and connected to a single ASU 1A1/SA20557 card as shown:- 1A1 ASU/SA20557 Port 1 1Port 2 1 Port 3 Port 4 2-W 0 2-W B 2-W G 6-Wires 4-W -17 2 [-3- Host Terminal Up to 3 TX69s The host terminal need not be fitted on port one, unless 3 TX69s are fitted. Terminations of the LJU for the TX69 are as follows:-

Secondary LJU TX69 Module 1 3 & 4 data (Orange)
Module 2 2 & 5 data (Blue)
Module 3 1 & 6 data (Green)

The actual colours and connections recommended. are identical to that of any Herald/Pentara terminal as shown above.

Supplied in the box with each TX69 module is a line cord, interconnect lead, 4 brackets and 6 fixing screws. A blanking plug is fitted in the left side socket, viewed from the rear. This plug must be removed before attempting to insert the plug of an interconnect lead if TX69 modules are to be connected in tandem. Where only a single module is provided, the line cord is fitted into the open socket and the blanking plug left in the spare socket to provide protection. The brackets are used to attach the module direct to the terminal or overlapped to provide a fixing to adjacent module.

Where only a single TX69 is required to be associated with a terminal, it is recommended a LJU 4/3A (Double Secondary) is used and connected as follows:-

6W W/0 O/W W/G G/W (A/d) 4 3 (B/d) 4 3 W/B B/W Key Module (A/L) 5 2 (B/L) 5 2 Terminal 6 1 6 1 LJU 4/3A In all cases, for easy consistent recognition, fit Terminals to the left socket, and Key Modules to the right socket.

Description                                           BT Item Code
Telephone  TX65  Ice Grey                             37 5549
Telephone  TX66  Ice Grey (LST)                       37 5550
Telephone  TX67  (No provision)
Telephone  TX68  Ice Grey (LST with Display)          37 5551
Telephone  TX69  Ice Grey (Busy Lamp Field Module)    37 5552
Line Jack  Unit  4/3A Required when TX69 is fitted    37 3907
Line Mastering   Module 1A (LMM 1A)                   37 5482
(Used in conjunction with LJU 4/3A when dedicated
2-wire telephone is provided for power fail working)

1/ The "Monitor" facility defaults to button 1 on all Self Configured systems. It is also the standard programming practise to allocate the same button for customised systems. However, there is no engineering reason that prevents any of the buttons being selected and used should the customer request it, or indeed, if the facility is not required, it can be inhibited by not allocating a facility button.

The "Self Test" routine is invoked by removing and reinserting the terminal plug from the LJU. Wait for the terminal LED's to glow steady, then press both "Recall and * buttons" together.

The following sequence of events now occur:-
a/ Wait for about 2 seconds until the LED's flash with an urgent cadence, now release both the Recall and * buttons.

b/ Press the terminal buttons in the following order. Buttons 16-1 large, or 8-1 for a small terminals (Top to bottom), Keypad 1-9, 0, #. Function Keys. Recall, Transmit, Program (double beep) and Hold.

The buttons MUST be pressed in the correct sequence, an incorrect button operation will respond with an Error Tone and the test will have to be restarted. Also, if no button is pressed within 5 seconds, the test times out, indicated by 3 short bleeps. Again the test must be restarted.

c/ Go off hook. The tone caller is activated continuously. If required, the volume and pitch of the tone caller may be adjusted. Going on hook turns the tone caller off.

d/ If the terminal under test is provided with an LCD, the display shows "SELF TEST", this will now change to a "Barber Shop" pattern for 2 seconds if no button is pressed. Pressing and holding down any button during this period will stop and freeze the display. It can be stepped slowly forward for inspection by pressing and releasing any button.

e/ At the end of the test, the LCD shows "SELF TEST OVER"

f/ The terminal now initialises for normal use.


With the obvious omission of keypad, LCD and fixed function keys, the module is tested in a similar manner.

The method for instigating the test is to remove and reinsert the Key Module line cord from the LJU. When the LED's glow steady, press and hold down the bottom button in both columns.

The following sequence of events now:-

a/ Wait for about 2 seconds until the LED's flash with an urgent cadence, now release both the buttons.

b/ Starting from the top, left column first, press each button in turn. The LED will light and a confidence beep is given after each press.

c/ At the end of the test, the Key Module initialises for normal use.

3/ If the customer will not accept that all power fail capability is provided at the 2-wire extensions on the system, then a dedicated socket/s must be provided free and fitted next to a terminals. It is the customers responsibility to provide an approved 2-wire telephones.

For convenience, it is recommended that a LJU 4/3A fitted with a Line Mastering Module (LMM 1A) is provided.


BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: November 01, 2010