The Magnaphone

Gallery opened 29 Sept 2024

Updated 16 Oct 2024

More on other cable systems added here
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The Magnaphone was a system for distributing music and news over a wide area through purpose-dedicated telephone lines. This article caught my eye because it mentioned water-cooled gramophone pickups, a concept I had not encountered before.

Left: The first page of an article on the Magnaphone: 1912

A very wordy introduction to the idea. Copy must have been in short supply for this issue.

The article is woefully short on technical detail, but we learn that one transmitting table (turntable) could drive one hundred subscriber lines.

Having a single start switch is not going to keep ten turntables in 'absolute synchronisation' but why should it matter if different groups of one hundred listeners are not accurately synchronised? If you were putting out some sort of schedule, eg 'Air on a G string' at 3:00pm a simultaneous start would be a good idea. But 'absolute synchronisation' seems both pointless and impossible.

Source: Popular Electricity, Dec 1912

Left: The second page of the Magnaphone article: 1912

At top left is the reference to water-cooled gramophone pickups, though they are described as 'transmitters'. The writer seems a bit confused because the water was for cooling, while the steam jacket on a steam engine cylinder is there to keep it hot, and so improve its efficiency. The need for cooling suggests that the gramophone pickups worked on the same principle as a carbon microphone; it would have to generate a hefty signal to drive 100 subscriber lines, and so a big current had to flow through it. The signal from the 'transmitters' was almost certainly passed through step-up transformers to match the impedance of the lines.

The image is not of stunning quality. but shows five turntables with tone-arms that have a big box over the needle end and a bigger box over the pivot end. This is consistent with a carbon-mic type pickup. On the nearest turntable it is just possible to see what look like two rubber hoses running into the tone-arm, presumably carrying the colling water; this must have imposed seriou side-loads on the needle.

There is a Wikipedia page on the system, which it calls the Tel-Musici system; no technical information is given. Where that name came from is currently unknown; it does not appear in the Popular Electricity article, and Googling has so far yielded nothing. The Wikipedia page says that 'Magnaphone' was actually the name given to the special loudspeakers used by subscribers.

Source: Popular Electricity, Dec 1912

Left: The end of the Magnaphone article: 1912

The man behind the system was George R Webb. He died in the 1918 influenza pandemic.

Source: Popular Electricity, Dec 1912

Left: The Tel-musici music room in Wilmington, Delaware: 1909

There is a row of turntables on the right, but no details are visible.

Source: Telephony magazine for 18 December 1909, p700. Article "Distributing Music Over Telephone Lines".

Left: The Tel-musici music room in Wilmington, Delaware: 1909

This is the switching system for connecting subscribers to the appropriate turntable. Note the horn loudspeaker above the switchboard.

Source: Telephony magazine for 18 December 1909, p700. Article "Distributing Music Over Telephone Lines".

Left: Tel-musici installation in a subscriber's home: 1909

This poor quality image unfortunately reveals very little. There is a horn like that of a gramophone resting on a table in the foreground; at the narrow end is a small black box which is presumably the loudspeaker.

Source: Telephony magazine for 18 December 1909, p700. Article "Distributing Music Over Telephone Lines".

Left: Magnaphone train announcing system: 1913

This brief article describes the use of the Magnaphone loudspeaker for announcing the arrival of trains in noisy stations. The thing with the small horn is a water-cooled carbon microphone; two light-coloured rubber tubes convey the cooling water (note the hand valve at the bottom of the microphone stand) and a black cable connects to the black box with a big lamp on top of it.

Water-cooled carbon microphones were often used in early radio broadcast transmitters.

Not all the text is legible, but it appears the lamp gave some indication that the microphone was working.

Source: Technical World Magazine magazine for 1913


OTHER CABLE BROADCAST SYSTEMS

The first audio distribution system was the Theatrophone which was introduced in Paris in 1881.

The Telefon Hírmondo (Telephone Herald) of Budapest began as a cable distributed newspaper in 1893; music was added later. Its technical director, Nándor Szmazsenka, built an initial cable network that divided Budapest into twenty-seven districts. It began with 43 miles (69 km) of cable, expanding to 372 miles (599 km) in 1901, and to 1,100 miles (1,800 km) in 1907. The system did not close until 1944, making it by far the longest-surviving distribution system.

The Budapest system used some sort of electromechanical amplifier in its early days, described as a "patented device that increased the sound". Similar devices seem to have been used in the Newark, New Jersey distribution system.


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