SEPTEMBER 8, 1923: WIreless Waves by "Condenser"

In the reproduction of all music, either by the ordinary telephone or by means of wireless, one of the greatest difficulties to be overcome is the trouble of distortion.

This difficulty is possibly more apparent in connected items, both vocal and instrumental than in solo work, and one of the reasons is that the metal diaphragm which is necessary to transform the electric impulses into sound waves is not able to accommodate itself perfectly to the movement of the music and the magnetism engendered remains too long.

In addition to the distortion already mentioned, there is always a certain metallic sound, whether the ordinary headphones or a loud speaker is used, and as long as it remains necessary to employ the metal diaphragm it will not be possible to do away with this element entirely, because even the thinnest of these diaphragms has this fault.

I have said that the metal diaphragm is a necessity for the reproduction of voices and instruments, but an invention that has recently been demonstrated avoids the use of metallic diaphragms as far as possible.

This new apparatus consists of three parts, the "kathodophone" or receiver for the sounds, a specially constructed amplifier and the "Statophone," a new kind of telephone for reproducing the sounds.

In the kathodophone the use of a microphone is not required, the item is delivered into a horn and the instrument contains a small rod of magnesia which is made hot by an electric current and ionises the surrounding air.

The degree of ionisation is varied by the sound waves received, and these are carried to the current which flows through the apparatus.

On reception, the specially constructed amplifier is first brought into use and then the statophone, which is an instrument built up of metal and mica, the metal only acting as a frame.

The statophone is based on the principle of the electrostatic telephone, and the two main parts of the apparatus are loaded respectively with positive and negative static electricity.

The electrostatic loadings of the mica part are influenced by the variations in the current received through the amplifier and the vibrations commence in these parts.

It is claimed that very clear reproductions are obtained with this instrument and only very little power is required to operate a loud speaker with it.

When certain improvements have been effected it is possible that the present means of transmission and reception will be superseded by this means, and without doubt some method will be adopted to obviate the metallic sounds and distortion which at present is largely caused through the metal diaphragm.

March 27, 2002 14:30