One of the theoretically attractive forms of receivers is the Braun
oscillograph tube, for it is so very easy to wobble the cathode ray spot
about over the fluorescent screen, to form figures. It has an
imponderable pencil of light which can be moved over the picture screen
with very little electrical energy. Its use has been proposed by many.
But the feature of the system which is most often overlooked in this
scheme is the necessity for an analytical picture machine at the sending
station, and no such device in satisfactory workable form has yet been
suggested.
The Braun tube system awaits, therefore, the attention of the
practical-application engineer before it can compete with other forms of
receivers.
[Illustration: [Photographs]]