Trimphone model range
Throughout its production run the Trimphone had a large number of different models and variations.
All GPO phones had model numbers normally stamped on the base of the phone, and as long as the numbers are still readable you can work out which model it is.
Original dial Trimphone (1964 to 1982)
The Trimphone went through several revisions before the final version, the 2/722, was offered in 1971. Trimphone model numbers were:
- Telephone 712 Mk1 - introduced May 1964
- Telephone 712 Mk2 - introduced March 1966
- Telephone 722 - introduced June 1966
- Telephone 1/722 - introduced November 1969
- Telephone 2/722 - introduced June 1971
The early Trimphones were supplied with lettered dials and these were shown on the Post Office's first publicity leaflet for the Trimphone. These are very rare.
All Trimphone dials had a transparent fingerplate over the numbers. Those on the 712 are subtly different and cannot be interchanged with the later 722 models.
The letters L and F after the model number indicate a lettered (L) or figured (F) dial. So Telephone 1/722L is a lettered dial version of the 1/722. The vast majority of phones for sale on eBay are of the 2/722 type with a figure dial.
The field trial phones can be identified by additional numbers on the base. To read more about the field trial phones, how to identify them and what the extra number on the base mean see: Field Trial Trimphone
Push button phones 1975 to 1982
- Telephone SA10006 - Push Button Trimphone, 1975
- Telephone 766 - Push Button Trimphone, 1977
- Telephone 786 - MF (touch tone) dialling version of PB Trimphone, 1979
Also look out for a special version of the Push Button Trimphone introduced to celebrate HM the Queen's Silver Jubilee. This was not the only Silver Jubilee phone; the GPO also did a special version of the Compact Telephone 776.
PST (modern socket) phone 1982
- Telephone 8722 - PST (Plug and socket) version of the 2/722, 1982
- Telephone 8766 - PST (Plug and socket) version of the 766, 1982
- Telephone 8786 - PST (Plug and socket) version of the 786, 1982
Courtesy of BT Heritage
Deltaphone - 1980
- Deltaphone - leather clad dial Trimphone
- Deltapone De-Luxe - leather clad push-button Trimphone
The Deltaphone was part of the GPO/BT's special range. They were more individual style phones. Subscribers had to pay significantly more to rent the special range, which included some antique style phones, some modern style designer phones and a Mickey Mouse phone.
The Deltaphone, which was STC's original name for the Trimphone, was a white Trimphone clad in leather. The Deltaphone only came in brown leather. The Deltaphone De-Luxe was a keypad version. You could get the Deltaphone De-Luxe in red or green leather.
Phoenixphone (Snowdon Collection)
The Phoenixphone was available as a dial Trimphone (8722) or a push-button one (8766) in a range of new colours: two-tone red, olive green/beige, two-tone orange, black/grey, light green/mid green and cream/brown.
By Steven Braggs, April 2014