No. 706,740.‘
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`n. A. rassaunan.
`WIRELESS SIGNALING.
`u'.pg1ic.ciun filed Sept. 28, 1901.)
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`Patented Aug. I2, I902.
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`APPLE 1017
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`1 UNITED STATES PATENT OFFIC ‘
`
`REGINAIJ) A. FESSENDEN, OF MANTEO, NORTH CAROLINA.
`
`WIRELESS SIGNALING.
`
`SPECIFICATION forming part of Letters Patent No. 706,740, dated August 12, 1909.
`Application filed September 28, 1901. Serial No. 76,836.
`(No model.)
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`55
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`70
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`75
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`To all whom it may coiwern:
`Be it known that I, REGINALD A. FESSEN-
`DEN, a citizen of the United States, residing
`at Manteo, in the county of Dare and State
`of North Carolina, have invented or discov-
`ered certain new and useful Improvements in
`Wireless Signaling, of which improvements
`the following is a specification.
`‘
`The invention described herein relates to
`certain improvements in selective signaling
`in systems Where the signal is transmitted by
`waves or impulses, and has for its object the
`generation at one station of persistent signal-
`ing impulses or Waves differingin character—
`9. g., period—aud to the generation of beats
`by the waves or impulses and the employ-
`ment of suitable receiving apparatus at the
`other station responsive only to the combined
`action of waves or.impulsescorrespondingin
`pe1'iod or other characteristics to those gen-
`erated.
`
`The invention is hereinafter more fully de-
`scribed and claimed.
`In the accompanying drawings, forming a
`part of this specification, Figure 1 is a dia-
`grammatic View of a form of apparatus adapt-
`ed to the practice of myinvention. Fig. 2 is
`a similar view of a modification of the appa-
`ratus shown in Fig. 1, and Fig. 3 is a graphic
`illustration of the method of signaling.
`In the practice of my invention I employ at
`the sendingstation two or more sources of
`radiation constructed to generate persistent
`waves or impulses, the Waves or impulses pro-
`ceeding from one of the sources of radiation
`diifering in character from those produced by
`the other source. At the receiving-station I
`employ a corresponding number of suitably
`tuned or adjusted receiving-conductors which
`by their conjoint action produce beats of any
`suitable character to operate an indicator,
`but are incapable of operating it except by
`conjoint action. The terms “sending-com
`doctor” and “receiving-conductor” as here-
`in employed include all of circuits from top
`to ground, if grounded, or, if not grounded,
`from one extreme end to the other extreme
`end of the circuits, including all apparatus in
`series with the circuits, while the term “radi-
`ating portion” includes all of sending-con-
`ductor from top or extreme end of the same
`to point of junction with apparatus for eifect-
`
`ing the oscillatory charging and discharging
`thei-eof—;such as sparking-terminals, trans-
`former-coils, armature-windings, (to. By the
`term “electromagnetic waves” as used here-
`in is meant electromagnetic waves long in
`periodcompared with what are called “heat-
`Waves” or
`“ radiant heat.” The terms
`“tuned” and “resonant” are used herein as
`'one to include the other.
`A convenient ap-
`paratus for this purpose is shown in the draw-
`ings and consists at the sending-station of
`two or more conductors having radiating por-
`tions 1 and 2, each being connected to a ter-
`minal or knob of an induction-coil, while the
`opposite terminal of the coil is connected to
`ground.
`In the form shown both the radiat-
`ing portions of conductors are connected to
`the terminal or knobs 3 of the induction-coil
`5, the other knob or terminal 4 being ground-
`ed. By any suitable means known in the art
`This
`, persistent oscillations are produced.
`persistence can beeifectod by so proportion-
`ing the resistance, self-inductance, and ca-
`pacity that only a small portion of the energy
`is radiated at each oscillation. This propor-
`tioning can be conveniently effected in the
`manner described in the application for Let-
`ters Patent filed May 29, 1901, Serial No.
`62,301. When two conductors are employed,
`they "should be so constructed and proper-
`tioned as to have difiercnt periods of oscilla-
`tions——as, for example, the period of conduc-
`tor 2 should be twenty-five (25) per cent.
`greater than that of conductor 1. This dif-
`ference is taken here for convenience in illus-
`trating by Fig. 3; but in general a smaller
`diiference, as five per cent., is preferred.
`At the receiving-station I employ two or
`more conductors 6 and 7, which are tuned to
`the respective sending - conductors by any
`suitable means, as by wires 8 and 9, which
`connect the conductors to a coherer 10 or other
`suitable Wave-responsive mechanism. Each
`of the wires 8 and 9 is preferably of approxi-
`mately the same length as the conductor to
`which it is connected. A grounding of the
`receiving-conductors is not necessary, as effi-
`cient signaling can be effected without a
`ground. When employing a coherer, it is
`connected, as usual, in the circuit of a bat-
`tery 11 and with a relay or other translating
`mechanism 12.
`A
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`706,740
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`When a spark passes between 3 and .4,
`waves of different periodicities are generated
`by the respective sending-conductors at the
`sending-station, and such waves will produce
`in the respective receiving-conductors 6 and
`7 correspondingly varying but persistent os-
`cillations of potential.
`_
`The first few oscillations of the series of
`waves will generate nearly the same poten-
`tial at the ends of the coherer or translating
`device; but as the oscillations persist there
`will be a rise in the potentials at the ends of
`the coherer, the rise at one end being greater
`than that at the opposite end. The approxi-
`mate equality of the potential during the first
`few oscillations is graphically shown in Fig.
`3 (where the full lines represent graphically
`the potential at the terminals of the wave-re-
`sponsive device and the dotted line repre-
`sents on somewhat smaller scale the differ-
`ence of potential between the terminals of
`the wave-responsive device) and also the dis-
`proportionate rise produced by one of the
`series of oscillations due to the persistence
`of the oscillations. As the coherer or other
`translating device is so constructed as to be
`unresponsive to approximately equal poten-
`tials or the potentials so nearly neutralize
`each other as to produce no operative effect
`on the coherer or wave—responsive device, it
`follows that the apparatus at any receiving-
`station will not respond to any Waves or series
`of waves or impulses which will not produce
`or generate at the coherer or other Wave-re-
`sponsive device potentials differing to a pre-
`determined degree, so that by properly ad-
`justing the sending andreceiving apparatus
`at the several stations any one of said sta-
`tions can be signaled to the exclusion of all
`others.
`-
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`In the form of apparatus shown in Fig. 2
`the sending-conductors are constructed with
`large capacity and self-induction, and the
`period of one of them, as 2*”, is greater than
`that of the other.
`I have found that good re-
`sults cau be produced if the period of 2“ be
`made about three (3) per cent. greater than
`that of 1“; but I do not limit myself to any
`particular difference in period. One of the
`radiating portions, as 1“, is connected to one
`terminal of a high-frequency alternator 13,
`which has its other terminal grounded. An
`alternator 13“, having a higher "frequency-—
`e. g. , three percent., more or less—than the al-
`ternator 13, thus corresponding to the period
`of the sending-conductor, of which it forms
`a part, has one terminal connected to the
`radiating portion 2“ and the other terminal
`grounded. While not essential,
`it is pre-
`ferred that these alternators, which are pref-
`erably constructed as described in applica-
`tion, Serial No. 62,301, filed May 29, 1901,
`should be driven from the same shaft or at
`the same rate. The receiving-conductors 6”
`and 7“ are tuned, respectively, to the send-
`ing-conductors and their radiating portions
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`are connected, respectively, to the terminals
`of two coils 14 14“, surrounding a core 15, said
`coils and core, with the diaphragm 16, form-
`ing a telephonic receiver. The opposite ends
`of the coils are connected to ground. By con-
`necting the alternators to the radiating por-
`tions, such connection being preferably ef-
`fected by a double-pole switch, waves or im-
`pulses are generated by the sending-conduc-
`tors and corresponding oscillations of poten-
`tial are produced in the receiving-conductors
`and the telephone-coils, and owing to the shift-
`ing of phase, as shown in Fig. 3, beats or sig-
`nals will be heard in the telephone.
`Broadly my invention consists in the pro-
`duction of electrical “ beats” analogous to
`sound-beats and their utilization in receiv-
`ing-conductors tuned to the sending-conduc-
`tors for wireless selective signaling.
`It is obvious that, as shown in Fig. 1, the
`sending- conductors employed as radiating
`sources may have a portion of their length
`formed by a common conductor. The con-
`struction here shown, While resembling in a
`slight degree that shown by Marconi, United
`States Patent No. 676,332, differs essentially
`from it in that though two conductors are used
`they are worked in parallel with one another
`and not in series, as shown by Marconi, and
`hence instead of being insulated from each
`other are preferably (and where aspark-gap is
`used almost necessarily) electrically connect-
`ed together, as shown in Figs. 1 and 2. The
`method of operation is also essentially differ-
`ent, as instead of producing a single perio-
`dicity from two conductors in series and using
`an inductance in such series circuit to pre-
`ventone conductor from neutralizing by caus-
`ing an initial change of phase the effect of
`the other in the method here shown two fre-
`quencies are used and there is no necessary
`initial change of phase.
`It is characteristic of the invention de-
`scribed herein that if two series of Waves dif-
`fering in periodicity and simultaneously gen-
`erated are caused to persist the difierence in
`phase will increase, so that if the receiving
`instruments be constructed to respond to only
`a particular difierence in phase signaling will
`not be effected by a shorter persistence than
`necessary to produce the desired difference
`of phase.
`The selective system herein described is to
`be differentiated from that described in my
`applications No. 18,878, filed June 2, 1900,
`and No. 53,441, filed March 29, 1901, in that in
`this system the indication is produced by the
`conjoint action of two or more sets of waves
`of difierent periodicities and not by the con-
`joint action of two mechanisms each sepa-
`rately actuated by a set of waves, the sets of
`waves being of different periodicities.
`I claim herein as my invention—
`1. In a system of signaling by electromag-
`netic waves, the combination of a source of
`Waves of different periodicities and two or
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`706,740
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`more receivers responsive respectively to the
`difiering wavesor impulses and a wave-re-
`sponsive device operative when the Waves or
`impulsesattain a certain predetermined phase
`relation, substantially asset forth.
`’ 2. In a system of signaling by electromag-
`netic waves, the combination of two or more
`sources producing waves of difierent perio-
`dicities, two or more receiving-conductors rc-
`sponsive respectively to the differing Waves
`or impulses and a wave-responsive device op-
`erative when the‘ waves or impulses attain a
`certain predetermined difference in phase,
`substantially as set forth.
`'
`3. In a system of signaling by electromag-
`netic waves, the combination of two or more
`sources producing waves or impulses of dif-
`ferent periodicities and two or more receiv-
`ing-conductors responsive respectively to the
`differing waves or impulses andia wavere-
`sponsive device operative by such waves or
`impulses when they attain a certain predeter-
`mined dilference in phase, ‘substantially as
`set forth.
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`4. In a system of signaling by electromag-
`netic waves, the combination of a generator,
`two or more ‘sending-conductors adapted to
`produce waves or impulses differing in peri-
`odicity,
`two or more receiving- conductors
`tuned to the’ sending-conductors, and wave-
`responsive device operative by the oscilla-
`tions in the receiving-conductors when the
`oscillations attaina certain predetermined
`difierence in phase, substantially as set forth.
`5. In a system ofrsignaling by electromag-
`netic waves, the combination of two or more
`sources of persistent waves or impulses of dif-
`ferent periodicities, two or more receiving-
`conductors responsive respectively to waves
`or impulses produced by the generators, and
`a Wave-responsive device operative by the
`oscillations in the receivers only when said
`
`oscillations attain a predetermined difference
`in phase, substantially as set forth.
`6. In a system of signaling by electromag-
`netic waves, the combination of means at the
`sending-station for generating two or more
`sets of waves of different periodicities and a
`wave-responsive device at the receiving—sta-
`tion operative by the conjoint action of such
`sets of Waves, substantially as set forth.
`7. In a system of signaling by electromag-
`netic wavos, the combination of a source of
`waves of different periodicities, two or Inore
`receiving-circuits reponsive respectively to
`the difierent Waves or impulses, and a current-
`operated, wave-responsive device operative
`when the waves or impulses attain a certain
`predetermined phase relation, substantially
`as described.
`
`8. In a system of signaling by electromag-
`netic waves, the combination of two or more
`sources producing Waves of different perio-
`dicities, two or more receiving-conductors re-
`sponsive respectively to the different waves
`or impulses, and a current-operated, wave-
`responsive device operative when the Waves
`‘or impulses attain a certain predetermined
`difference in phase, substantially as set forth.
`9. In a system of signaling by electromag-
`netic Waves, the combination of means at the
`sending-station for generating "two or more
`sets 01": waves of different periodicities, and a
`current-operated, wave-responsive device at
`the receiving-station operative by the con- 75
`joint action of such sets of Waves, substan-
`tially as set forth.
`In testimony whereof I have hereunto set
`my hand.
`
`REGINALD A. FESSENDEN.
`Witnesses: ‘
`DARWIN S. WOLCOT'P,
`Trrno. S. MUKINS.
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