The Response 120 handset is similar to the Relate range.

The BT Response 120 is a mains powered, fully digital, processor controlled combined telephone answering and recording machine giving many advanced facilities within a compact case design which may be desk or wall mounted. Response 120 comes with a pre-recorded announcement which can either be used to answer calls or may be over-written. The maximum length of a message is two minutes with a total recording time of six minutes. Response 120 may be wall mounted.

The Response 120 facilities are as follows:-
Answerphone facilities:-

Announcement: Response 120 comes complete with a pre-recorded announcement.
The pre-recorded announcement may be over-written by a personalised announcement of up to 2 minutes duration. To record the announcement lift the handset and press and hold the ANNOUNCEMENT key. A beep will be heard after which recording via the handset, may commence. When the recording is complete, release the ANNOUNCEMENT key. Response 120 will automatically replay your announcement and reset itself to answer calls.

Announcement check: Press ANNOUNCEMENT key and the announcement will be replayed.

Message Play: Press PLAY/PAUSE/REW key. This will play all messages through the loudspeaker. For privacy, lift the handset.

Pause: Press the PLAY/PAUSE/REW key. To continue listening press the key again. Maximum pause is 60 seconds, after which the Response 120 resets and all messages are saved.

Message Save, ALL messages: After The Response 120 has replayed all messages, press and hold the ANSWER/SAVE/SAVE key until a beep is heard. All messages are then saved.

Message save, INDIVIDUAL messages: While the message to be saved is being replayed, press the ANSWER/STOP/SAVE key. The current message is then marked for saving and Response 120 moves to the next message. All unmarked messages will be deleted when all messages have been played.
NOTE: At the end of message play, Response 120 sorts the saved messages to create space for new messages. During this short wait, the message indicator is lit and the power indicator is not lit.

Searching through messages: During playback of the messages, operation of the PLAY/PAUSE/REW key will cause the Response 120 to search backwards through all messages for as long as the key is held down, or until the start of the first message. A long beep will be heard to indicate the gap between messages.

Stepping through messages: Press the "*" key during or at the end of a message and the Response 120 will skip to the start of the current message. Press it again, (within 1 second) and the Response 120 will skip to the beginning of the previous message. Use the "#" key in a similar manner and the Response 120 will skip forwards through the messages.

Message indicator: The green LED will flash when a message has been received. The number of flashes indicates the number of recorded messages.

Branchphone reset - Will release machine from the line should a parallel telephone handset be lifted. This facility is inhibited for 0.5 seconds when machine first answers, therefore the facility may not always appear to operate.

Call Screening: Volume Control must be turned up to listen. The volume control emits a short beep when altered and two beeps when the top or bottom volume ends are reached.

Answer Delay: Response 120 will answer the first call after four rings and if a message is left, subsequent callers will be answered after two rings. This is useful during remote access: If three rings are heard, no messages have been recorded.

Remote set to Answer: Call machine and let it ring 20 times to turn machine on remotely. Mains supply to machine must be turned on.

Remote Access: Response 120 may be accessed remotely from a Touchtone telephone or by using a remote controller. Access may be gained by dialling the telephone number of the Response 120 and listening to the announcement. After the long beep at the end, pause and then press "#" for three to six seconds. Response 120 will beep once and replay all recorded messages. When the final message has been played, two beeps will be heard. If the handset is replaced at the end of message replay, all messages will be saved.

If the "#" key is pressed again (3 - 6 seconds) after the two beeps, all messages will be replayed.

Deleting messages remotely: After the two beeps following the last message, wait for approximately eight seconds when a further single beep will be heard. Press "#" for three to six seconds, Response 120 will respond with two beeps and all messages will have been deleted. Wait for a further eight seconds, during which it is possible to decide not to delete the messages. If so press "#" again (3 - 6 seconds) and the messages Will be saved and replayed. If the deletion can go ahead, after eight seconds, replace the receiver.

Telephone facilities:

Memory stores: Response 120 can store ten numbers of up to 31 digits. Recall #'*" and "#" may be stored but must be followed by a pause. This counts as two digits stored.

Two numbers may be stored under each memory store key. To store a number, lift the handset and press STORE, press the desired memory key and key the telephone number to be stored. Press STORE and replace the handset.

To store a second number, lift the handset and press STORE followed by SHIFT and then the desired memory store key. Key the number to be stored, press STORE and replace the handset.

Dialling a stored number:
Lift the receiver and press the required memory key. If the number is a second number press SHIFT followed by the desired memory key.

Deleting a stored number:
Lift the handset and press the store key followed by the desired memory store key, preceded by SHIFT if necessary. Press STORE and replace the handset.

Network Services: Memories 4 and 5 are pre-programmed for use with extra services: These are 4 - Call Waiting and 5 - Charge Advice. these stores may be over-written by the user with a number of their choice and used as normal. If line and mains power are removed for more than five minutes, the network service defaults will be reinstated.

Ringer volume:
High low or off, set by a slider switch on the underside of the instrument.

Tone-earth (T-E), tone-timed-break (T-TB) or loop disconnect (P-E). Set by a slider switch on the underside of the instrument. Pressing the "*" key during a call when in loop disconnect mode, will change the signalling to tone for the duration of the call.

Made by Hughes Microelectronics Europa Ltd in the UK

Distributed by BT outlets and BT UK Trade Sales. Supplied on Sale and Rental terms via BT outlets, sale only from BT UK Trade Sales.

Approval Number for Response 120 is S/4039/3/P/502792
Approved as supplied for connection to the Public Switched Telephone Network (PSTN) and PBX 2-wire extensions.

The Response 120 is not approved for use on Shared Service lines or as an extension to a payphone. They are not suitable for use on PBX's where manual ringing is applied.

Unapproved modifications must not be carried out on this instrument, to do so would invalidate approval making connection to the PSTN unlawful.

The Response 120 may be wall mounted.

A Phone Socket and a 240 volts, 13 amp, 50 Hertz mains supply are required within 2.0 metres of the Response 120.
The Response 120 is suitable for use on Phone Socket installations on DELs and most types of PBX extensions that provide automatic ringing.
The Response 120 has a Ringer Equivalence Number (REN) of 1. It is intended for use in normal Domestic, Residential or Business locations. They are not suited for use in bathrooms or other locations prone to damp or condensation.

Approximate overall dimensions are:
230mm x 130mm x 85mm (L,W,H): Weight 750 grams (excluding transformer).

The machine contains no on-site serviceable parts, therefore maintenance is limited to functional testing, checking the output of the plug-top transformer, that the line cord is correctly connected and the facility switches are set for optimum performance of the machine to match the line to which it is connected. Response 120 is fully digital and does not use magnetic tapes or batteries.

If the machine has failed completely, the output voltage of the Transformer should be checked. The output is marked 7.5V AC, but will measure about 10 volts when tested with the output open circuit.

New units carry a 21 month warranty from the date of manufacture, identified by the first 4 digits WW YY **** (Week and Year) of the serial number marked on the underside of the machine.

BT guarantee sold machines for 12 months from the date of purchase to the customer irrespective of the date of manufacture.

Customers should return faulty items along with the receipt to the point of purchase where they will be repaired or replaced free of charge.

Description					BT Item Code
Response 120, Alpine White 			870605
Response 120, Ocean Green			870661
(Items are complete with transformer)
BT Remote controller				870427
Transformer 754					870625
Transformer 753					870505 may also be used

Power indicator
The red LED indicates that power is being supplied to the unit. A flashing LED indicates that power had failed but is now restored.

Stored telephone numbers will remain for approximately five minutes if both power and telephone line is disconnected. If either power or line only is disconnected, the stored numbers will be held.

If the power is removed from Response 120, the personalised message will be replaced by the default pre-recorded message and all recorded messages are lost. The Response 120 will reset to answer all calls when power is reconnected.

The power LED will continue to blink until the default announcement is played or a new personalised announcement is recorded.

On-site maintenance of the Response range is limited as the equipment contains no serviceable parts. Some routine servicing - detailed in the User Guide should be carried out by the customer, but field maintenance is restricted to checking the facility switch settings and testing the power unit output.

Several adapters used with Response instruments are marked with lower outputs than those actually measured. Approximate voltage readings (with the output open circuit) are as follows:-
Transformer 19B (marked 13.5V DC) measures 19 - 20v.
Transformer 752 (marked 9V AC) measures 11 - 12v.
Transformer 753 (marked 9.5V DC) measures 13 - 14v.


There have been reports of the Response 120 not answering incoming calls when connected in parallel with two or more instruments. This problem is made worse if the Response 120 ringer is set to 'high'. Removing the other instruments on the circuit may provide some service but this is not a permanent solution.

The problem has been caused by a mismatch of components on the ringing detect circuit preventing ringing being detected if the current is too low.

There is now a modification available via the manufacturer.


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Last revised: October 30, 2022