Improvements in Apparatus Employed in Wireless Telegraphy.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Apparatus Employed in Wireless Telegraphy.
We, GUGLIELMO MARCONI, Electrician, and THE WIRELESS TELEGRAPH AND
SIGNAL Co. LD., both of 28, Mark Lane, in the City of London, do hereby
declare the nature of this invention to be as follows:-
In the Specification of a former Patent granted to me No. 12039 of 1896 I des-
cribed an arrangement in which the transmitter consisted of a sparking appliance
having one terminal connected to an insulated conductor in the air and the other
terminal to earth, whilst the receiver contained a sensitive tube or sensitive im-
perfect contact, having one end connected to a similar conductor and the other
end to earth.
When both instruments are employed at the same station it is found that the
sensitive tube or sensitive imperfect contact is liable to injury by its close
proximity to the sparking appliance.
order to obviate this objection I enclose the receiver, containing the sensitive
tibe or sensitive imperfect contact, in a box of thick metal having only a small
pening into it, and I employ the same conductor and earth plate for both
instruments.
The earth plate is permanently connected to one terminal of the sparking
appliance and to the outside of the box. The insulated conductor can be connected
by a plug either to the other terminal of the sparking appliance or to the other
end of the imperfect contact.
Where a recording instrument is employed this cannot conveniently be placed
inside the box and in order to prevent the wires connecting it to the relay of the
receiver from leading injurious oscillations to the sensitive tube I adopt the
following arrangement:-one terminal of the relay circuit is connected to the
inside of the box and one terminal of the recording instrument to the outside.
The ends of the wires from the other terminals of the relay circuit and
recording instrument are connected to the end's of a coil formed from an insulated
wire covered with tin foil. This coil is outside the box and the tin foil is in
electrical communication with it.
C
1000
G. MARCONI.
THE WIRELESS TELEGRAPH AND
SIGNAL COMPANY LIMITED.
G. MARCONI,
H. JAMESON DAVIES,} Directors,
HENRY W. ALLEN,
Secretary.

page_text: We, GUGLIELMO MARCONI, Electrician, and THE WIRELESS TELEGRAPH AND
SIGNAL COMPANY LIMITED, both of 28, Mark Lane, in the City of London, 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:
In the Specification of a former Patent No. 12039 of 1896 an arrangement is
described in which the transmitter consisted of a sparking appliance having one
terminal connected to an insulated conductor in the air and the other terminal
to earth, whilst the receiver contained a sensitive tube or sensitive imperfect
contact, having one end connected to a similar conductor and the other end to
earth.
When both instruments are employed at the same station it is found that the
sensitive tube or sensitive imperfect contact is liable to injury by its close
proximity to the sparking appliance.
In order to obviate this objection we enclose the receiver, containing the sensitive
tube or sensitive imperfect contact, in a box of metal having only a small
opening into it, and employ the same conductor and earth plate for both
instruments.
The earth plate is permanently connected to one terminal of the sparking
appliance and to the outside of the box. The insulated conductor can be connected
by a plug either to the other terminal of the sparking appliance or to the other
end of the imperfect contact.
Where a recording instrument is employed this cannot conveniently be placed
inside the box and in order to prevent the wires connecting it to the relay of the
receiver from leading injurious oscillations to the sensitive tube we adopt the
following arrangement:-one terminal of the relay circuit is connected to the
inside of the box and one terminal of the recording instrument to the outside.
The ends of the wires from the other terminals of the relay circuit and
recording instrument are connected to the ends of a coil formed from an insulated
wire covered with tin foil or other conducting material. This coil is outside the
box and the tin foil is in electrical communication with it.
Figure 1 is a diagram of a combined transmitting and receiving station arranged
in accordance with this invention. Figure 2 shows the wire of which the coil B
is made.
The letters so far as they are applicable are the same as those employed in the
former specification.
a is a battery and b an ordinary Morse key closing the circuit through the
primary of a Rhumkorff coil e the terminals of the secondary being connected
to metallic balls c. 7 is a battery and h a telegraphic instrument on the derived
circuit of a relay n. j is a glass tube containing metallic powder. are choking
coils in the circuit through the tube. is a trembler on the relay circuit for
tapping the tube. q is a resistance coil. is a battery in the relay eircuit.
is a resistance inserted in derivation across the terminals of the trembler p
and is a resistance in a circuit connecting the vibrating contacts of the
trembler.
u is an
s is a resistance across the terminals of the relay circuit.
aerial conductor. These arrangements are now well known and are fully des-
cribed in the former specification.
According to our present invention we enclose the receiver in a metallic box A.
About 20th of an inch is a suitable thickness for the metal.
The inside of the box is connected by a wire A' to the relay circuit and its

page_text: outside by wires A2 A3 to one terminal of the telegraphic instrument / and earth E
respectively.
The other branch of the relay circuit is connected by a wire A' insulated from
the box to the other terminal of the instrument h. B is a coil on the wire A*
and outside the box. It is protected from mechanical injury by a metal case C
but this may be omitted. The coil B may contain about 20 yards of wire 75th of
an inch in diameter and have 120 turns.
The wire is insulated with gutta percha D) which is covered with a metallic
conductor as shown in Figure 2. We use tin foil for convenience. The tin
foil is in electric connection with the box. The aerial conductor u can be con-
nected by a flexible conductor G, plug G and spring contacts H and H¹ either to
one of the balls e for transmitting or to one end of the tube j for receiving.
The other end of the tube j is connected by a wire J to the inside of the box.
The aerial conductor need not be insulated as shown but may be connected to
earth through the primary of an induction coil the ends of the secondary of which
are connected to the ends of the sensitive tube.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. The combination of a transmitter, a receiver, an aerial conductor, a metallic
box containing the receiver, earth connections to one terminal of the transmitter
and to the box, an interchangeable connection from the aerial conductor either
to the other terminal of the transmitter or to one terminal of the receiver and
a connection between the other terminal of the receiver and the box.
2. The combination of a transmitter, a receiver, an aerial conductor, a metallic
box containing the receiver, earth connections to one terminal of the transmitter
and to the box, an interchangeable connection from the aerial conductor either to
the other terminal of the transmitter or to one terminal of the receiver, a con-
nection between the other terminal of the receiver and the box, a relay operated by
the receiver, a telegraph instrument outside the box, a connection between the box
and one terminal of the relay, a connection between the box and one terminal of
the telegraph instrument and a connection insulated from the box between the
other terminals of the relay and telegraph instrument.
3. The combination of a transmitter, a receiver, an aerial conductor, a metallic
box containing the receiver, earth connections to one terminal of the transmitter
and to the box, an interchangeable connection from the aerial conductor either
to the other terminal of the transmitter or to one terminal of the receiver, a
connection between the other terminal of the receiver and the box, a relay operated
by the receiver, a telegraph instrument outside the box, a connection between
the box and one terminal of the relay, a connection between the box and one
terminal of the telegraph instrument, a connection insulated from the box between
the other terminals of the relay and telegraph instrument, a coil of insulated
wire (preferably) outside the box in the latter connection and a metallic covering
to the insulation in connection with the box.
4. Apparatus for wireless telegraphy substantially as described and illustrated
in the drawings.
R
1000