US1101914A - Apparatus for electric signaling. - Google Patents

Description

R. A. PESSENDEN.

APPARATUS FOR ELECTRIC SIGNALING. APPLICATION FILED MAR. 31, 1908.

1,101,914. Patented June 30,1914

5 SHEETS-SHEET l.

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R. A. FESSBNDEN.

APPARATUS FOR ELEGTRIO SIGNALING.

APPLICATION FILED MAR. 31, 1908. 1

1,101,914 Patented June 30,1914.

6 SHEETSSHEET 2.

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J) J7 J; 58 4 m I s? I as Z5 77 INVENTOR.

R. A. FESSENDEN.

APPARATUS FOR ELECTRIC SIGNALING. APPLICATION IILED MAR. 31, 1908.

1 1M314, 4 Patented June so, 1914.

5 SHEETSSHEET 3.

IN VEN TOR.

R. A. PBSSENDEN.

APPARATUS FOR ELECTRIC SIGNALING.

I APPLICATION FILED MAR.31, 1908. 1 ,11,914. Patented June 30,1914

- SHEETS-SHEET 4..

Fly.

INVENTOR.

R. A. FESSENDEN.

APPARATUS FOR ELECTRIC SIGNALING.

APPLICATION FILED MAR. 31, 1908.

Patented June 30;1914.

5 SHEETSSHEET 5.

IN VEN TOR.

I TNESSES orurnn smarts ornron.

REGINALD i1. FESSENDEN, OF BRANT ROCK, MASSACEU$ETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 SAMUEL or. KINTNER, OF PITTSBURGH, PENNSYLVANIA, AND

HALSE'Z M. BARRETT, GE FBLGU'MFEZELID,

AEABATUS FER ELECTRIC SIGNALENG.

NEW JERSEY, RECEIVERS.

manner a.

To (ZZZ whom it may concern:

Be it known that l, REGINALD A. Fnssnnnan, a citizen of the United States, residing at Brant Rock, in the State oi Massachu/ setts, have invented certain new and useful Apparatus for Electric Signaling, of which the following is a specification.

My invention relates to the art of wireless signaling, and more particularly to the so-called antennm for transmitting and receiving tie impulses. its primaryohgects are; to avoid the great cost of erecting and maintaining high supporting structures; to enable more eiicient transmission and receipt of signals without interference from atmospheric disturbances or other causes, andto generally improve the methods and means of signaling by electromagnetic waves.

The invention is illustrated in several forms in the accompanying drawings, wherein Figure 1 is a diagram illustrating one simple and effective form of my apparatus for sending wireless messages. Fig. 2 is a diagram of apparatus used for receiving messages. Figs. 3 and i are diagrams illustrating forms of antennae in which several elements areconnected in parallel. Fig. 5 shows a modification in which the elements are connected in parallel series. Fi 6 is a diagram showing in elevation a further modification of apparatus for my purposes. Figs. 7 and .8 are respectively a plan and an elevation diagram of another form of apparatus suitable for carrying out the invention. Fig. 9 is an elevation of still another form.

Heretofore it has been customary to generate and receive electromagnetic waves byusing either vertical antennae which may or may not have a horizontally extended portion, or vertical loops, which respectively utilize the electro-static and the magnetic components of the waves. Horizontal antenna, broadly, also have been used, as shown in applicants prior Patent No. 706738 of August 12th, 1902. V

In order to utilize the electrostatic and electromagnetic components it has been necessary to erect high towers -or large loops. The great height of the towers or loops has rendered their construction very expensive, as a tower 600 feet high would Specification of Letters Patent.

cost approximately $48,000, while a loop to Patented June 341 1914. Serial No. 424,372.

accomplish the same results would cost still more, since two towers are necessary in such case. l have discovered a new way of generating and receiving the waves, by utilizing what may he considered as ponent of the waves. For this purpose, instead of using high tower or great loop, l use a long approximately horizontal conductor, or a conductor having a horizontal. component, extending, or having its horizontal component extending, in the direction of propagation of the waves and grounded either directly or inductively both ends, and connect the transmitting or receiving instrument in this horizontal conductor.

This plan has number of advantages: For example, it is very much. cheaper, since a horizontal conductor 600 feet long will give practically the same results as a tower 400 feet high. The cost of land necessary is less since a tower requires a large amount 0 land for guying and stretching the antennae, while for the horizontal antennae only a right of way is necessary, the horizontal wires being merely elevated to a height suitiicient to permit of traiiic passing under it. It is also advantageous in that the horizontal conductor receives and sends mainly in the direction of its length from two directions diametrically opposite to each other and so produces little or no interference with stations placed alongside of it. It also enables one to obtain without limit the effect of high towers. For example, it would evidently be impossible to erect a tower a mile high, but there is no difliculty in constructing such a horizontal aerial several miles long. i

The method and apparatus have been found to be eflicient in actual practice. With a horizontal antenna of an efi'ective length of 600 feet and consisting of a single wire grounded at both ends, with condensers inserted in the circuit for tuning, and with a receiver conductively connected in the horizontal conductor, 1 have received messages transmitted over a distance of 900 miles. Also by inductively connecting an oscillatory sending circuit to a horizontal aerial of this type I have transmitted messages over a distance of hundreds of miles.

The novelty of my device, in so far as the theory is now known, resides in utilizing the.

the current comlid current set up in the earth with. a conductor and placing a receiver in the conductor so that the currents which would otherwise :tlow through the earth, flow through the horizontal conductor in shunt to the earth, ellect the rec a; 'larly in the waves it s1 iposed that V .equency osciilatir circuit sets up rapid oscillations between the two ends the honiontal conductor the high fr qu ncy currents generated by the source i o the ground at both ends the conductor and being propa ated outwardly over the earths surface. uch a horin ntal antenna. used in receiving should have some component pointing toward the wave source, The best arrangement i zontal antenna point as whole toward the source from which the waves come, and similarly the sending antenna should be directed toward the receiver. This fact indi cates that it is the current component which is being utilized.'

in prior systems the components out the electromagnetic waves utilized were the components at right angles to the direction of propagation, and therefore the efi cctiveness ot the apparatus depended to a considcrahle extent upon the height of the antenna: or loops used. in my system the component used is the component in the direction ot propagation, and it is tor this reason that the horizontal wires both at the sending and receiving ends should lie in the direction of propagation.

, in lc igs. i and2, which illustrate respec tively the sending and receiving stations of an apparatus constructed in accordance with my i, vention, 2 represents the horizontal antenna, which preferabiy extends parallel with the surface of the ground and is supported on poles which be constructed like ordinary telephone poles, and grounded at the ends through variable capacities 3, which may he of any known construction. This antenna is of considerable length, and, as above stated, l have found an effective length oil? 600 feet to be suitable for trans mitting and receiving messages at a distance of 900 miles. Ordinary copper wire may be employed to constitute the antennm.- The sending instrument for sending the electric waves is interposed at some suitable point in the conductor, as l show at 4, the primary a of a transformer interposed in the antenna, the secondary i of which is in circuit with a condenser 5 and a spark gap 6. An electric generator 7 is in circuit with atransmitting key 8 and connected by a transformer 9, 10,130 circuit 10 and the cir-' cuit of the spark gap on opposite sides of the condenser 5. 1

In the receiving apparatus shown in Fig. 2 the antenna 2 may be ofconstruction similar to that in Fig". 1, and it is provided with to have the llO'lf'l;

v i c1 3 other figures oi the drawings i or modifications of my invention which designed give greater eiiicicncy to the neral apparatus as just described and illustrated in l and 2.

i n I lln l o, Ishow a series or approiti horizontal sending conductors each of whose ends ll, l2, l8, and i l, 15, i6 respectively, are grounded and which contain variable coi'idensers l7, l8, i9, 20, 21, 22, for tuning the circuits, and coils 29, 30, 31, respectively, which form the secondaries of transformers whose primaries 2G, 27, 28, in a local exciting circuit, operated by a source such as the high frequency alternator 32. The iield 35 of the alternator, excited by battery has in circuit a key 33 which upon hein'g depressed causes the alternator to produce electric oscillations in the horizontal conductors, and the waves are sent out mainly in tlllQClllfiCtlOIl of said conductors.

The circuit of the primaries also contains variable condensers 23, 24:, 25 for tuning the circuits. lily this use of a number oi horisontal conductors in parallel l attain much stronger effects and greater elliciency. The

circuit of the alternator 32 should be tuned 65, 66, 67, are in series and contain variable condensers 56, 57, 58, 59, 60, 61, (32, as before for tuning the circuits, and the primary 74; or another transformer Whose secondary 68 is in circuit with a condenser 75, which may be variable, a receiver 76, which is lit a t: I

It 0 ti preferably a liquid'barretter, a potentiome- 1 tel 77, and an indicating instrument such as the telephone receiver 78. By this arrangement the cumulative effects of a number of the horizontal antennae are added together and give an increased effect on the receiver.

In the arrangement of Fig. 5, the sending antennae 80, 82, 81, 83,84, 86, 85, 87, similar to those heretofore described and similarly containing variable condensers 88, 89,, 90, 91,

its

a re 96, ()7, 518,91),

92, 93, 91, and 95, are arranged in parallel series and contain the secondaries 100, 101, 102, 103, of transformers whose primaries 'lhe circuits of all the priniaries are connected. to a high frequency alternator 101, and the signaling is done by key 33 as before described in the case of l ig. 3. The primary circuits also contain the variable condensers 105, 106, 107, 108, and the inductances 109, 110, arranged as shown, and used for tuning the primary circuits.

In the modification of Fig. 6 the horizontal receiving conductors or'antennte 111, 112, 113, 114, are connected in series, and consist each of a number of parallel wires as shown; the series is grounded at 115, 116, through variable condensers 117, 118, and supported upon insulated posts numbered 130 to 137 consecutively. Between the several groups of conductors are condensers 119, 120, 123, and inductances 121, 122, for tuning the circuit in sections. 121 is the primary of a transformer whose secondary 125 is in circuit with condenser 126, receiver 127, potentiometer 12S, and indicating instruments such as a telephone receiver 129.

In the modification of Figs. 7 and 8, I provide for sending, a series of horizontal wires 1218, 139, 140, 141, 142, 113, joined together at their inner ends through the capacity 115 and secondary 144 of a transformer whose primary 1113 is in circuit with a high frequency alternator 147 or any other suitable means producing the oscillations,

such for example as an arc. The outer ends of the horizontal conductors are connected to sets of parallel circumferentially ar ranged horizontal conductors 148, 149. These are preferably arranged nearer the ground than the other conductors 138 .to 11 1, so that the outer circumferential portion of the antenna has greater capacity to ground than the radial portion, while at the same time by using a number of radial conductors. the self-induction is kept as small as possible without interfering with the capacity to ground at the outer ends being maintained large. The conductors are supported through insulators on posts 150, 151, 152, 153, 15 156, as shown in Fig. 8, and 1 preferably provide also the conductors numbered respectively 157 to 1131), which form a wave chute or artificial ground, which I find to produce anincreased and more reliable etfect.

Fig. 9 shows a preferred modification in which the horizontal conductor 167 is grou'nded'at both ends at 168 and 169 and also in the middle at 188.

170, 171, and 172 are condensers, preferably variablc.

173 and 174 are variable inductances.

175, 176, 177, 17 S are switches for cutting out the condensers and inductances when desired.

179 is a transformer coil and 180 and 18]. are transformer coils in inductive relation to coil 17).

182 is a high frequency alternator and 183 a sending key.

181 is a receiver such as a liquid barretter, and 185 and 1813 are switches for disconnecting the liquid barretter when sending with the key 183.

The grounded ends may be connected by a metallic conductor as shown at 187.

It will be seen that the circuits 179, 172, 17:1, 170, 1138 and 179, 172, 17 1, 171, 169 virtually form two circuits such as shown in the prior part of the specification, but placed back to back so that when used for sending the phases of the impulses at the two outer ends are the same at the same instant.

By means of the construction above described, electrical waves of great intensity can be transmitted and are mainly localizedin the direction of the antenna. By this means 1 also avoid the great expense of constructing high towers and other elevated supports, besides being unlimited in gaining the effects of the high vertical antennae. 1 thus not only greatly reduce the cost of operation but reduce the amount of power necessaryf The possibility of interference and especially atmospheric disturbances, which interfere with signaling when using high towers, is to a great extent avoided.

It is preferable that the resistance of the horizontal conductor to ground should be low. \Vhere terminal capacities are used they should therefore be very large so as to produce a small back voltage. lVhere direct grounds are used they should be constructed in such a way that their olnnic resistance is much lower than that of the usual ground, for example by constructing a trench of some length, say 100 feet, preferably at right angles to the direction of propagation or re ceipt. As an illustration, the resistance of the grounds should be a small fraction of an ohm, such as one hundredth of an ohm, instead of five to twenty five ohms 'as is the case with the grounds usually constructed.

It will be noted that by the use of a high frequency alternator in this apparatus, I produce the minimum of disturbance in the other circuits, and by. this device in connection with my devices for maintaining constant intensity of radiation, and devices for signaling'by changing the tune, interferences with other stations can be avoided entirely.

Having thus described my invention and illustrated its use, what I herein claim as new and desire to secure by Letters Patent, is the following:

1. Apparatus for signaling by electromagtennae the series grounded at both ends uni adapted to operate by the earth current of the Waves, said sets connected in series and each series containing tuning devices.

3., @everst composite and cumulatively fi ittt titfi fx acting horizontal component antennae connected in series and means to sepstetely odjnst the parts of said series.

In testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

REGINALD FESSENDEN.

Witnesses:

THoMAs B, BLACKMAN, Jsssm E. BnNro

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