GPO Dialphones (5) : 776

The final development of the mass market General Post Office dialphone, the 776 was first introduced in 1977. It was based on the 746, with much the same circuitry, but had a lighter smaller body and a separate bell unit. This bell unit could be installed in a wall bracket (my example is one of these).

The 776 was the first telephone developed by the GPO intended for the home market, previous models like the 746 had been designed for business users first (but of course by the late 1970s were in use in thousands of homes). Separating the handset and bell unit reduced the size of the telephone and also made it lighter to carry. It also meant that the bell could be placed in a different location in the house to the handset, such as in the hall.

The 776 came in three colours: blue, light grey (as mine is) and brown. A special dark blue (called Balmoral blue) edition was also released to mark Queen Elizabeth II's Silver Jubilee in 1977.

GPO Dialphones (4) : 722 Trimphone

The Trimphone was introduced by the General Post Office in the 1960s as an alternative to standard telephones such as the 706. The Trimphone had a number of features that made it stand out from the standard telephones, and hence customers had to pay extra for one!

The Trimphone had a more fashionable, slimmer design compared to the likes of the 706 and 746, and was much lighter. However, the lighter weight did end up causing issues with customers with the telephone sliding about when being used, especially when dialing.

The most notable change though was the sound, the Trimphone had a distinctive warble for it's ringer using electronics rather than the bell on earlier telephones. The Trimphone also has an illuminated dial (thanks to some mildly radioactive substance in the dial!) The Trim in Trimphone is in fact an acronym for Tone Ring Illuminator Model. The Trimphone was released as the 712 and 712L (with a lettered dial) in the mid-1960s in limited areas, and nationwide in 1968.

Production switched to the 722 and 722L models which had a number of improvements and refinements. Production of the Trimphone continued until 1982. We have two Trimphones, a grey 722 and a green 722L with a two colour dial.

GPO Dialphones (3) : 741

The wall-mounted counterpart to the 706 was the 711. Naturally, when the General Post Office switched to the updated 746 telephone there followed a wall-mounted version of this updated telephone.

This was the 741, which was introduced in 1968 and replaced the 711. It had a similar case to the earlier wall-mounted telephone but had the internals of the 746 including the built-in regulator.

Compared to the 746, the 741 had a quite different case (see below for side-by-side comparison). The 746 is designed for desk use so needs to present the dial at an angle to aid dialing, the 741 needs to present it's dial "flat" to the user for the same reason.

The 741 has an integral bracket for mounting securely on the wall. The handset rests atop the modified case. Our 741 has "KS" scratched on the case, perhaps these were the initals of a previous owner, presumably not Keir Starmer!

GPO Dialphones (2) : 746

The General Post Office introduced the 746 telephone in 1967, replacing the 706. The 746 was a refinement of the earlier model, the biggest external change was to the cradle for the receiver which could double as a handle to carry the telephone. So, you could walk around while on a call and try and look cool.

Internally, the 746 had the regulator, which had been optional on the 706, built into the circuit board. The regulator could be used to vary the current flowing into the receiver and transmitter of the telephone as telephone lines too close to an exchange sometimes had trouble with the current on the line being too high.

The 746 remained in production for a long time, some were later modified to use the BT New Plan plug (the type still used today). These were known as the 8746 telephone and can still be used now with a supported line (though this will soon change).

I have three 746s in my collection: red, brown and topaz yellow.

Red phone

Topaz yellow phone

Black 706 (left) and 746 (right), showing the external difference

Brown telephone

GPO Dialphones (1) : 706

In the past, the General Post Office had a near monopoly (apart from one town) of the British telephone system. Subscribers to the service had to rent a handset from the GPO who designed and had manufactured a series of telephones.

The General Post Office released it's 706 model telephone in 1959, a modernised version of earlier GPO telephones with inspiration taken from contemporary American designs. The 706, and it's later update the 746, remained in production for decades and can still be used today if retro-fitted with a New Plan BT socket.

The 706 was fitted with an optional regulator which could reduce the sensitivity of the telephone if the line was too close to a telephone exchange or even if the telephone was picking up interference from nearby strong radio transmissions. The 746 had this regulator built into it's circuitry.

One variant of the 706 was the 706L which had a lettered dial. This was useful in the age of letter coded telephone exchanges. I have black and ivory examples of the 706 dialphone in my collection. 

Dialing a 776

Another telephone dialing video, this time a GPO 776.

776

Another dialphone has joined the collection, a fine but slightly shabby GPO 776. This was the last dialphone designed by the Post Office and was the first intended principally for the residential instead of the business market. After this BT (as they became) would go push-button only on their new telephone models leaving this model as a final last gasp of a more civilised age.

Dialing a 706L

The second GPO 706L dialphone i have received actually has a working dial unlike the first, so how about some retro dialing action?

Cream 706L

Another General Post Office dialphone has joined the collection, and another 706L. This one is in cream and has a clear dial unlike my original black 706L, the dial also works on this phone too. A lovely looking telephone.

Yellow phone

This month's purchase of retro office technology is a telephone, another GPO 746 to be exact. I have three of them in various colours, the latest is in a very pleasing yellow. It doesn't have a plug so can't be connected to the telephone line, though i don't have a land line anyway! To find out more about the 746, and to see my red one, click here.

706L

I have got quite a few dialphones now, including a couple of 746s and a 722 trimphone, but one type i didn't have was a 706L - well until now anyway! Unfortunately, the dial doesn't really work anymore but other than that the telephone looks superb.

741

I've bought another dialphone, a GPO 741 this time. I now have four dialphones, which is impressive considering i don't have a landline! The GPO 741 is a wall mounted version of the classic General Post Office telephone, it only works when mounted on a wall due to where the cradle is. 

Dialing that number

Something a little different, a video of me dialing a number on one of my GPO 746 telephones. Unfortunately the telephone is not plugged into any network so i might be waiting a while for someone to pick up!

Making a telephone call across the Atlantic in 1947

How to make a call to jolly old England back in 1947.

The voice of Alexander Graham Bell

Despite the fact his inventions like the telephone have helped billions of people hear other voices (and record voices and sounds) no one knew what Alexander Graham Bell's own voice sounded like (apart from people who knew him at the time of course).

One of the earliest wax disc recordings from 1885, which comes complete with a written transcript by Bell, has been scanned using a non-invasive optical sound recovery process and the audio extracted by calculating how a stylus would move through the grooves of the disk. So here it is, one of the earliest audio recordings.

Telephone Jukebox

Whilst watching the 1942 movie X Marks the Spot the other day I was taken by surprise by a rather interesting piece of technology in the movie. In a bar a man walks up to a large jukebox in the corner and puts in a coin. Instead of manually choosing a record he spoke into a microphone and was connected to an operator in a central office. Then his choice of record was found and put on a turntable, the music then piped to the jukebox in the bar.

These Telephone Jukebox systems ran in a number of US cities for a while in the mid-twentieth century including Manhattan (setting in the film). Music was transmitted over premium quality phone lines to the jukebox and while not what we would consider high quality these days was probably sufficient bandwidth for a 78rpm record.

Rock-Ola was the producer of such a device, the rather fine looking Mystic Music Jukebox. The central office served up to thirty jukeboxes. The Rock-Ola boxes also had up to twenty records stored inside it locally so users wouldn't always have to use the remote service (the machine in the movie seems to have a list on the front of it, maybe these were the records stored on it). The key advantage of a telephone jukebox being, of course, the much wider range of music that was available, from a few dozen held locally to a few hundred [1].

One of the most successful of these devices was the Multiphone by Kenneth C. Shyvers which at one stage had eight thousand machines in use. This system required two dedicated phone lines, one to speak to the operator (based in Seattle) and the other for the music [2]. These systems began to appear in the US in the late 1930s and survived in cities like Washington until the late 1950s. By then the improved technology of 45rpm singles (which of course had better sound quality than 78s and also were more compact) rendered the Telephone Jukebox (which wasn't a cheap system to run) obsolete.

Scenes from the movie

The operators look for a record 

A considerable collection of 78s

[1] Barry Ulavov, "The Jukes take over swing", American Mercury (October 1940) p. 177
[2] Gert J. Almind, Coin-Op Telephone Music <http://juke-box.dk/gert-telephone-music.htm>

Old telephone numbers

Two examples of older telephone number formats. The first is of an old shop sign in Erdington (now changed) but well into the late 1990s it still listed ERD as part of the telephone number.

B.Jones on Slade Road

This means you would dial the numbers on your phone (in those days a dial phone) corresponding to ERD, which meant you dialled 373 - still an Erdington code. As it was listed in letter format it was considered easier to remember. I wonder why this practice ceased?

GPO dial phone (at York museum)

The other is a sign at Wilmcote railway station in Warwickshire. For emergencies you would call Worcester! Presumably you would call via an operator.

Sign at Wilmcote railway station