TELEPHONE No. 9701
Tremolo

Key features:

• Pulse dial only
• Last number re-dial
• Microphone cut-off (secrecy)
• Tone caller with two position volume control
• Table or Wall mountable
• Inductive Coupler receiver inset

Colours: Biscuit, Red, Black, Almond and Blue

Approval number: S/1000/3/F/500162

 

Additional Information

Made by Northern Telecom and BTCE Cwmcarn (Manufacturers code FWG)

Introduced circa 1986 and was on sale terms only from 1st April 1988

Telephone No. 9701 has a Ringer Equivalence Number (REN) of 1.

A plastic peg is supplied with the telephone, this should be fitted to the gravity switch plunger to prevent the handset from falling off the cradle when the instrument is wall-mounted.  The peg is fitted by pushing the two prongs into the holes in the plunger and snapping off the excess lug.  The line cord may be re-routed along the retaining channels on the base of the instrument alongside the handset cord if required.  A 300mm line cord is also available for wall mounted use.

Line and handset cords are plug ended and may be removed by pressing down the retaining clip on the plug with a pointed implement and gently pulling the cord.

TESTING
Idle - Normal Capacitor Loop test conditions via the master socket and tone caller circuit.
The Telephone No. 9701 draws typically 12 ma line current whilst on-hook to retain last number re-dial memory, this may result in low resistance loop line test-conditions.

Seized - Normal off-hook press button telephone loop.  The electronic keypad and transmission circuitry may give high resistance telephone-loop line test conditions as with other press button telephones.

Telephones No. 9701 receiver insets are designed to provide an inductive coupling effect to benefit users of 'inductive coupler' behind the ear type hearing aids.

Early version Telephones No. 9701 (Item coded 870176, 870177, 870163) were withdrawn from new supply during August 1986 for rework to overcome magnetic problems with the handset.

Later versions (Item coded 877115, 877116, 877117) were withdrawn from new supply during January 1987 for modification to prevent cords from being unplugged from the telephone without the use of a tool.

Models that have been modified to overcome this later problem are marked with a yellow spot on the box and instrument base for identification, models produced during 1987 will incorporate modified cords on production

Modified and new models will continue with the existing Item Code numbers.

Tremolo telephones manufactured by Northern Telecom prior to 1986 week 32 have good RF1 immunity from 100kHz to 10Mhz but poor immunity to higher frequencies.  Those manufactured since 1986 week 32 have fairly good RFI immunity from 100kHz to 150Mhz and may be identified by the year and week marking (i.e. first digits of the eleven digit serial number) on the base of the telephone.

All Tremolo telephones manufactured by BTCE Cwmcarn have fairly good RFI immunity from 100kHz to 150Mhz.

Telephones No. 9701 manufactured before week 43 of 1986 may cause 'repeated digits' to be pulsed out when making outgoing calls, resulting in `wrong number complaints'.  Models made after this date should not be affected.  There will be no dual signalling or MF4 signalling versions of Tremolo.

Northern Telecom also adapted this telephone into a phone called the Ireland Dial Phone.  Click here for more details

Last revised: April 23, 2021