Improvements in Wireless Telegraphy.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Wireless Telegraphy.
SIDNEY GEORGE BROWN, 22, Holland Road, Kensington, London, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in wireless telegraphy especially in
the method of arranging the radiating and receiving wires.
The transmitter and receiver may be provided with two vertical or horresontal
wires, a wire coupled to each side of the spark gap, or receiving coherer, and
placed approximately at say half a wave length apart, with or without an earth
connection.
These wires may or may not be closed at the top, or joined through a small
capacity, and a rectangular or other shape may be given to the wires so as to
enclose an area.
If a spark gap at the generating station is provided with vertical wires, earth
connections or other equivalent devices, the wave length the whole system shall
generate can be settled and fixed by placing suitably shaped insulated conduc-
tors between the two outer spark balls, or by arranging the immidiate surround-
ings of the spark gap, by these means a reflector preferably constructed of straight
or wire gauze can be placed behind such radiating wires, and within a much
shorter distance than the whole or half length of such vertical wire.
Instead of an earth connection, the other side of the spark gap may be coupled
to the reflector which may be insulated, the vertical wire being held in place by
suitably shaped insulators fixed to the reflector.
I have found it convenient in many cases especially if the vertical wire was
connected to one of the middle balls of the spark gap to place a small capacity
across the high-pressure terminals of the spark coil, an inductive circuit being
placed if necessary between such capacity and the spark balls.
It might in many cases be more convenient to multiply the number of radiating
systems rather than increase the height of the wires.
In this case it would seem convenient to have separate windings on one spark
coil for all the systems, while if the receiver was to be treated in a similar way
I should place vertical wires one behind the other and having some relation to
the wave length, and coupled in series.
Dated this 14th dow of Tulv. 1900

page_text: SIDNEY GEORGE BROWN, 9, Putney Hill, Putney, "late of" 22, Holland Road,
Kensington, London, Electrical Engineer, 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:-
According to this invention the transmitting apparatus is provided with two
radiating wires coupled one to each terminal of the sparking device and the
receiving apparatus is provided with two receiving wires coupled one to each
terminal of the coherer.
These radiating and receiving wires are respectively placed at a distance apart
which has a definite relation to the length of the signalling waves, that of half
a wave length being a convenient distance.
The said wires may be closed at the top or not and they may or may not be
provided with an earth connection.
This placing the wires half a wave length apart causes the system. to send its
waves or receive them from mainly one direction, which direction would seem
to be that of the plane of the wires.
If the vertical wires were not so carefully adjusted to the wave length they
would transmit or receive the Hertzian waves from any direction.
The vertical wires may or may not be closed at the top or joined through a
small capacity and a rectangular or other shape may be given to the wires, and
the rectangle may consist of more than one turn of wire, so as to enclose an area.
By arranging a condensor across the high potential terminals of the spark coil
and joining the terminals of this condensors to the spark balls through highly
inductive coils I can increase the persistance of the waves; the condensor acting
as a storage of power, and maintaining the potential at each side of the spark gap.
The highly inductive coils prevent the charge in the condensor from itself
oscillating across the spark gap.
By thus increasing the persistance of the train of Hertzian waves due to each
disruptive discharge, the receiving circuit can be caused to be in tune or syntony
with the transmitting circuit, thus rendering the system more sensitive and less
likely to be interfered with by neighbouring systems differentially disposed.
The wave length that any system may generate is to a certain extent under
command and it is necessary if parabolic reflectors are to be used to keep the
waves short.
This can be done by suitably arranging the spark gap, such as by employing
suitably sized intermediate balls or by placing inductive coils on the arms of the
radiating wires.
By thus keeping the length of the waves short the use of parabolic mirrors
behind the radiating and receiving wires and within a much shorter distance of
said wires than that of their length or half their length as has heretofore been
thought necessary is rendered possible.
These mirrors which should be constructed of reticulated metal such as fine
wire netting or its equivalent, have the effect of reflecting the waves to, or
receiving them. from one definite direction and thereby restricting the wave or
telegraphic effect to a given direction.
In order that my invention may be clearly understood and readily carried into
effect I will proceed to describe the same more fully in connection with the accom-
panying drawing in which,
Figures 1 and 2 are respectively diagrams of transmitting apparatus and

page_text: receiving apparatus in which the radiating and receiving wires project vertically
into the air.
Figures 3 and 4 are respectively diagrams of transmitting apparatus and
receiving apparatus in which the radiating and receiving wires are put to earth.
Figure 5 shows a parabolic mirror in position behind a radiating or a receiving
wire arranged according to this invention.
Referring to Figures 1 and 2, a and a are the radiating wires of the trans-
mitting apparatus, a, a are the receiving wires of the receiving apparatus and
are preferably arranged in the same plane with the wires a a¹. is the battery
and is the transmitting instrument, in the primary circuit of the induction.
coil C of the transmitting apparatus.
K is a condensor placed across the high potential terminals of the secondary
winding of the induction coil C.
SSS are the spheres or balls of the sparking device.
L L are inductive coils placed between the terminals of the condensor K and
the terminals of the spark balls S S, the ends of the radiating wires a a¹ at one
extremity being also respectively connected to the terminals of the said spark
balls.
Vis a rotary vibrator of well known construction placed in the primary circuit
of the coil C.
R is the receiving relay or other receiving instrument is the battery in the
circuit of the receiving relay d is the coherer in the receiving relay circuit, to
the terminals of which coherer the wires a² a³ are connected.
LL are inductive resistances placed respectively between the terminals of the
coherer d and the receiver R and battery but in many cases L2 L³ are unneces-
sary as the relay winding R does usually, and the shunting resistance, if used,
may possess sufficient induction of their own.
Upon depressing the key of the transmitter t; which for high speed working
would be replaced by a Wheatstone transmitter; the circuit of the battery b is
closed and the primary winding of the coil C is energized through the vibrator V
in the well known manner.
For fast speed signalling this vibrator V which makes and breaks the current
for the primary winding of coil C, should be kept constantly working whether the
coil is energized or not.
When the coil C is thus energized sparks pass between the balls S and the
Hertzian waves thereby generated, are radiated by the wires a a¹. The con-
densor acts as a storage of power, maintaining the potential at each side of the
spark gap and thereby increasing the persistance of the waves.
The coils L L prevent the charge in the condensor from itself oscillating
across the spark gap, whilst permitting the currents from the secondary winding
of the coil to pass steadily to the spark balls.
When no signals are received the coherer d is maintained in a decohered or
non-conductive condition, and the circuit of the receiver R and battery b¹ is con-
sequently open.
When the signalling Hertzian waves are received by the wires a² a³ the said
waves pass through the coherer d rendering it conductive and closing the circuit
of the receiver R and battery b₁ the signals being recorded by the said receiver.
The radiating wires a a and also the receiving wires a a³ are respectively
placed at a distance apart which has a definite relation to the length of the Hert-
Zian waves generated.
This distance may be conveniently half that of the Hertzian wave length, such
an arrangement causing the positive radiating wire to supply, the positive crest
of the wave at the same time as the-negative radiating wire supplies the negative
crest of the wave and the waves to be thus transmitted or received mainly in the
direction of, the plane of the radiating and receiving wires.
In Figure 3 the battery b, transmitter t vibrator V, induction coil C, con-
densor K and sparking spheres S are arranged as in Figure 1.

page_text: The radiating wires a a¹ are respectively connected to earth plates E E and
are preferably arranged at a distance of half, one and a half, or more wave lengths
apart.
K&K are condensors respectively inserted between the terminals of the spark
balls and the radiating wires a a¹.
In Figure 4 the recording instrument R the battery the inductive resis-
tances L L and coherer d are arranged as in Figure 2.
The receiving wires a² a³ are connected respectively to earth plates E E and
are preferably arranged at a distance of half, one and a half, or more wave lengths
apart and in the same plane with the wires a a¹.
K and K are condensors respectively inserted between the terminals of the
coherer and the receiving wires a² a³.
The operation of the apparatus shown in Figure 3 and 4 is substantially the
same as that shown in Figure 1 and 2.
The condensors K' K² prevent the radiating wires a a¹ being short circuited by
earth and the condensors KK prevent the receiving wires a² a³ being short
circuited by earth.
The radiation (with the apparatus shown in Figures 3 and 4) keeps to the sur-
face of the ground.
By arranging the inductive coils L L' and the condensor K as above described
the Hertzian waves are kept persistant.
The persistance of the waves enable the transmitting and the receiving wires
to adjusted in tune or syntony, so that they will be more sensitive to one another
and will not be likely to be interfered with by differentially disposed neighbour-
ing systems.
The shortness of the waves enable a parabolic mirror of wire gauze or its equiva-
lent as e in Figure 5 to be placed a short distance behind the vertical wire v, or
wires, for the purpose of reflecting the waves in a definite direction.
One side of the spark gap, instead of being earthed may be connected to the
mirror e which latter would then be insulated; or if one side of the spark gap is
earthed, the mirror may be also earthed, but not insulated.
In all the foregoing I may multiply the systems, coupling the wires in parallel
or in series as the case might be.
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
1 claim is--
1. In wireless telegraphy, the combination with the transmitting or receiving
apparatus of two radiating or receiving wires, attached one to each side of the
spark gap or coherer substantially as described.
2. In wireless telegraphy, the combination with the transmitting or receiving
apparatus of two parallel vertical radiating or receiving wires attached one to
each side of the spark gap or coherer and arranged at a distance apart which has
a definite relation to the length of the signalling waves, substantially as described
for the purpose specified.
3. In wireless telegraphy the combination with the transmitting or receiving
apparatus of two wires attached one to each side of the spark gap or coherer, the
ends of the wires being earthed substantially as described.
4. In wireless telegraphy the combination with the transmitting or receiving
apparatus of two wires attached one to each side of the spark gap or coherer, the
ends of the wires being connected to earth plates, which are placed at a distance
apart which has a definite relation to the length of the signalling waves, con-
densors being inserted in the path of the wires substantially as described and
for the purpose specified.
5. In wireless telegraphy the combination with the transmitting or receiving
apparatus of two wires attached one to each side of the spark gap or coherer and
bent so as to enclose an area.

page_text: 6. In wireless telegraph apparatus the combination with the transmitter, the
battery, the induction coil, the sparking spheres, and the radiating wires of a
condensor placed across the high potential terminals of the induction coil, and
inductive coils placed between the terminals of said condensor, and the terminals
of the sparking spheres, substantially as described and for the purpose specified.
7. In wireless telegraphy, a reticulated metallic parabolic mirror or reflector
placed behind the wave radiating or receiving wires substantially as described.
8. Apparatus arranged substantially as described and illustrated in the accom-
panying drawings.
4 114 day of Amil 1900