The four low profile terminals titled TX55 to TX58 are intended for use on "THE PENTARA 100 Phone System".
The terminals are approved for connection to existing Herald Phone Systems and were not offered until stocks of TX51 and TX52 terminals were exhausted.
The terminals use electronic speech circuits in conjunction with specialised handset transducers and therefore it was not possible to fit or use any of the facility handsets available.
These terminals have continuously variable volume controls for the tone sounder and an internal link for altering the pitch of the tone sounder, but none of the new terminals have Power Failure working capability.

TX55 - Standard Terminal (Basic 4-wire terminal)
Seven programmable facility buttons with associated LED's are available and the instrument incorporates a monitor loudspeaker. In addition to the 12 button keypad there are dedicated buttons for Recall, Transmit, Program, Hold and Monitor.

Unlike previous Herald terminals, the monitor amplifier will be cancelled after making a hands free call when the handset is lifted.

TX56 TX57

TX56 - Standard Loudspeaking Terminal
The TX56 has all the features of the TX55 with the addition of a loudspeaking facility and a latching Mute key for microphone cut off when used in the hands-free mode.

TX57 - Large Loudspeaking Terminal
The TX57 is a larger version of the TX56 with 18 programmable facility buttons and associated LED's.

TX58 - Large Loudspeaking Display Terminal
The TX58 has all the features of the TX57 with the addition of a 16 character LED display for system messages.
Suffix A terminals have recently been introduced and offer greater immunity against Radio Frequency Interference.

Made by Philips TMC Limited

Approval Number 5/1000/GF/198l/PR

Approved for connection to the Herald and Pentara system as described in PXML 63.




Telephone TX57A Grey 375529
Telephone TX58A Stone   375127
Telephone TX58A Grey 375530
Telephone TX57 Brown 374942
Telephone TX57 Stone 374943
Telephone TX57A Brown  
Telephone TX57A Stone 375170
Telephone TX58 Brown 374944
Telephone TX58 Stone 374945
Telephone TX58A Stone 375172
Telephone TX58A Brown  
BACK Home page BT/GPO Telephones Search the Site Glossary of Telecom Terminology Quick Find All Telephone Systems

Last revised: November 01, 2010