The Houston daily post. [volume] (Houston, Tex.) 1886-1903, 1900-05-22
Mnrconi's system.
(Concluded.)

Mnrconis system.
In This system as used for directed sig
mails there is no vertical wire, and the
transmitting spark gap and the cohercr
are each placed in the focus OF para
bolic mirror. The coherer is here the
receiver OF the wave as well as the de-
tector. and it's position Is important. (in
this case the transmitter and the receiver
must be tuned to the synchronism by
strips of copper of carefully adjusted
lengthy AS usually practiced, however,
for undirected signals, vertical wire
Is used at each end, and The exact posi-
ton of the transmitting spark gap or
The coherer becomes matter of no great
Importance In this case the osciilator
and It's spark gap serve. only to charge tie
vertical line 10 the necessary potential.
Trains of waves are shut out from this
vertical line throughout its length, al
though they are probably stronger near
the earth. plate or ball at the top or
the wire is therefore help in most cases,
as 1t makes the waves more uniform. The
waves are radated in all directions hor-
lzontally, but the vertical radiation Is
probably weak.
The portion of the ether waves striking
the vertical wire at the receiving end is
absorbed by the wire, and il the potential
is high enough discharge passes, caus-
ing the coherer to act The potential Of
this current is high because Of the enor-
mously high rate of cutting, the waves
passing with the speed of light The
coherer is here not the receiver but only
detector of the charge upons the vertical
wire. and its position in the circuit does
not matter. The first part of the oscllat-
ing discharge, because of its high am
plitude. is much the most effective, and
the tuning Of the receiving circuit to any
particular frequency Is therefore neither
necessary nor useful.
Functions of the Apparatus.
In the diagram of the receiving circuits
there is shown a coil on each side or the
coherer in The local circuit. These coils
are inductive reslstances, or Choking
coils" in which the rapidly oscillating
current flows with great difficulty. They
serve to prevent the waste of the energy
of the ether waves which would occur If
the discharge could pass freely in this
circuit. and they compel the discharge
TO pass wholly through the coherer.
The action of the relay. the Taper and
the recorder are probably sufficiently we'll
understood from what has gone before In
each instrument the break is shunted by
non -inductive high resistance. high
this purpose. These shunts were found
to be necessary to proven. sparkling and
consequent disturbance of the coherer. The
Taper and the recorder produce disturb
ances unless shunted which prevent the
coherer from returning to its sensitiYe
condition, and thus reduce the distance at
which signals can be received.
Recent improvements.
When both receiver and transmitter are
used a the same station the coherer Is
likely to be injured by it's nearness to the
oscillator, Marcon has therefore found 1t
desirable to inclose all the receiving ap-
paratus except she recorder in a metal
case with a small opening and COM
bined capacity and inductance is added to
prevent the oscillations of the transmit
ter affecting the coherer. At such a sta
tion the same vertical wire is used for
both transmitter and receiver, being
switched from osclllator to coherer as de-
sired. The use of this remaining box and
other improvements and alternative ar
engagements form the subjects OF patents.
One of these improvements consists in
the use of an induction coil of special de-
sign, the vertical wire discharging through