Improvements in Apparatus for receiving "Hertz" Electric Undulations or Waves.
Year: 1899

page_text: Date of Application, 9th May, 1899-Accepted, 7th Oct., 1899
Improvements in Apparatus for receiving "Hertz" Electric
Undulations or Waves.
I, EUGÈNE DUCRETET, of 75, Rue Claude-Bernard, Paris, France, Inventor, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
-
This invention relates to improvements in radioconductors (tubes charged with
filings, dust or powder) such as are used in wireless telegraphy for receiving
electric waves or undulations projected into space the improvements being
designed to ensure a more perfect reception and utilization of the electric waves.
The improved radioconductor is represented on the accompanying drawings,
in Figs. 1, and 2, in sectional elevation; and comprises a tube, T, of glass,
ivory, steatite, or other suitable insulating material, fitted with internal rods P¹,
Pi, or P¹, Pi, pu, adapted to fill the interior of the cylinder or tube as com-
pletely as possible, excepting as regards the space or spaces occupied by the fil-
ings or powder, L, L', so as to reduce the space within the tube to a minimum
and avoid displacement and renewal of the contained air, and with heads or
ends, E, E, serving to permit of the adjustment of said rods P¹, P, Pш, and
for making contact with the apparatus which constitutes the complete wireless
telegraph receiver, and packed at g, g¹, to ensure the closing of the tube ends.
But two rods may be used (vide Figs. 1,) in which case either one, (P1,) of the
rods, P1, P1, may be adjustable as represented, or both of the rods may be simi-
larly adjustable, or three rods may be used (vide Fig. 2,) in which case, a central
rod, P, is secured within the tube with an outside electrical connection by means
of a screw, E, and both of the outer rods, P¹, Pш, will be adjustable.
The rods, P¹, P, P, may be of any metal and their ends or faces (between
which the metallic grains filings, or powder, L, L¹, are placed,) may be plated
or coated with nonoxidisable metals, or, the rods may have an additional appendage
of amalgamated metal, or may be formed with a cavity adapted to receive a
little mercury, with the object of creating within the tube T an atmosphere of
vapours of mercury.
The arrangement represented in Fig. 2, allows of different combinations with
external circuits; but it is necessary that contact be made with the exterior of T',
at Elli
The metallic filings or dust indicated at L, L', may be of any metal or alloy:
but I prefer to use grains of hard steel obtained by crushing or grinding; steel
alloyed with metals such as silver, rhodium, platinum, or chromium, with the
object of obtaining a suitable degree of oxidability. This state of hardness
obtained by tempering, whether by water or any liquid or by air or compression,
is suitable for obtaining grains of convenient size.
Following the knowledge of the arrangements already known and used in electric
telegraphy and long distance telephony and my own works on sensitive electric
relays, and for the purpose of ensuring a high efficiency of action of my radio-
conductors whilst diminishing the effects of atmospheric disturbances and earth

page_text: currents, I shall always be able to use in the external circuits connected to the
electrodes of the radioconductor, (Figs. 1, and 2,) condensers (whose capacity may
be variable and capable of regulation) together with small induction coils (whether
with free poles or with a single pole) and to avail myself of their self-induction as
well as the transformation that can be obtained by the same.
In order to obtain the best conditions of reception of the hertz electric waves,
it is thus, in certain cases, necessary to diminish and suppress the perturbating
effects produced by earth and atmospheric currents.
Suitable arrangements which enable me to obtain a good reception with the
herein before described improved radioconductors are represented, by way of
example, in Figures, 3, 4, 5, and 6, of the drawings.
When the radioconductor, Br, (Fig. 3,) is single, as that represented in Fig. 1,
it can be interposed in an electric circuit comprising a battery, P, and a sensi-
tive relay, R, as well as a condenser, Co, of variable capacity in connection with
the earth, T. The same arrangement can be employed when there is used a
multiple radioconductor, Br¹, (Fig. 4,) like that represented in Fig. 2. The
battery, P, may be arranged on the right or on the left of the relay, R.
The reception of the electric waves may further be improved by joining in the
circuit of the radioconductor or the relay, R, the battery, P, and the condenser
of variable capacity, Co¹, a single pole induction coil, I, (Figs. 5, and 6,) and a
second condenser, Co, connected to the earth, T.
In Figs. 3, 4, 5, and 6, C indicates a wire insulated in space and serving to
considerably increase the sensitiveness of the tube charged with filings by per-
forming the function of a real "collector of waves."
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In radioconductors, in combination, a tube containing grains, filings, powder
or dust suitable for the use of the instrument, internal rods nearly filling the tube
and leaving but a small interspace in which the grains filings powder or dust
are or is located, and end caps or heads serving to adjust the rods and to establish
an electrical connection thereof with an electric circuit and fitted with packing
serving to close the tube ends, as set forth.
2. The arrangement hereinbefore described with reference to Fig. 1.
3. The arrangement hereinbefore described with reference to Fig. 2.
4. In radioconductors, the application and use of grains of hard steel alone or
alloyed with metal capable of having the desired degree of oxidability and obtained
by crushing or by grinding, as set forth.
Dated this 9th day of May 1899
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicant.