US2483504A - Triple element autodirectional antenna system - Google Patents

Description

Oct. 4, 1949. uTscHow ET 2,483,04

TRIPLE ELEMENT AUTO DIRECTIONAL ANTENNA sYsTEE Filed July 13, 1948 3 Sheets-Sheet l INVENTORS CHARLES R. REESE 6 ARTHUR wsmscuow ATTOQIVEXI' 4, 49. A. H. eu'rscs-aow ETAL 943,594

TRIPLE ELEMENT AUTO DIRECTIONAL ANTENNA SYSTEM 3 Sheets-Sheet, 2

' INVENTORJ CHARLES R REESE a? ARTHUR newscuow ATTOkA/EXS Oct. 4, 1949. A. H. GUTSCHOW ETAL 2,4354

TRIPLE ELEMENT AUTO DIRECTIONAL ANTENNA SYSTEM Filed July 1s, 1.948 s Sheets-Sheet 3 J7 I V I6 1/ is a 8 63 8 a 15 a f/ fl 0 l o o 48 p mvslvmns CHARLES R. REESE. m ARTHUR nsmscuow i BY ATTORNEY,

maeaoau UNITED STATES PATENT Mme TRIPLE ELEMENT AUTODIRECTIONAL ANTENNA SYSTEM Arthur H. Gutlchow, Drum, N. Y., and Charles B. Reese, Ghent, Ky.

Application July 13, 1948, Serial No. 38,484 3 Claims. 348-100) 1 I 2 This invention relates to television antenna Figure 8 is a cross-sectional view t k n on line systems, and more particularly to television H of Figure 6. antenna systems of the multiple element type. Figure 8a is a cross-secti al View mu A main object of the invention is to provide t0Fig r 8 but illustl'fltingamodifled y Switch a novel and improved television antenna system 5 i a for e wi h he System01 Figure 1. wherein individually tuned and oriented antenna At the present time, public television broadcast elements are provided for the various television facilities in the United States are licensed by the channels to be received, whereby each channel Federal Communications Commission to operate may be received with maximum efficiency, instead on 13 channels, each channel being 6 megacycles of limiting the maximum efiiciency of reception in wide. The 13 authorized channels are divided to one channel or adopting a compromise antenna into two groups. The first group, of six channels, arrangement as is done where a single antenna are located in a band extending from 44 to 88 element is employed for receivingall channels. I megacycles and the second group, of seven h A further object of the invention is to provide nels, extend from 174 to 216 megacycles. an improved multiple-element antenna system 15 Although at present regular operation on all for use with television receivers, providing indithe available television channels is not yet being vidually tuned and oriented antenna elements for carried on, many of the larger cities in the the respective channels to be received, and country have at least one television broadcast wherein a novel and eflicient switching arrangestation in operation and some have as many as ment is employed for automatically changing three stations engaged in regular commercial from one antenna element to another as the rebroadcasting. It is expected that within a few ceiver is switched from one channel to another, years, most of the geographical areas in the and wherein the antenna lead-in connections are country where television receivers may be emvery simple, making the antenna system easy ployed will have service available from at least to install and to maintain in correct adjustment, three diiferent television broadcast stations. We 2,: re z'ssznvsizaczzhzi assistants; tion will ecome apparen rom e o owing description and claims, and from the accom- $83 21 6 2 8 isgr at fl' directions win s, wherein: gi 1"; a ichematic wiring diagram of the so The practice heretffore' has been to employ signal inputportion of a television receiver emz g a g $355 gg fig l z gi ggs gg gg g figg f i iz fi gfggfi flfigfi ifl fg jggfi gf In the early stages of development of the art, vention the authorized television broadcast band extended 5 Figure 2 is an elevational view, partly in cross- 3 $3 222 5 2 128:: als ig gzi gi ggg 3 section, of a multiple-element television antenna emciency at a mean frequency in this banda'ssembly employe'fl in the improved system of Also the orientation of the antenna was such thepresent invention t that if more than one station was available for Flgflre 3 is perspectwe exploded de new 40 reception, and if the stations were at different showmg method employed for comfectmg the directions from the receiver, the antenna could dipqle termmals to cross'bar stlpportmg not be directed so as to receive all stations with her the *P assem b1y of Flgure optimum efficiency. In general, a compromise Flgiure 4 1s a perspectlve exploded detall,view orientation of the antenna was employed. showmg the method famployed for supportmg It can readily be seen that where some of the folded dipole m desn'ed plane in the assembly broadcast stations are in the upper band extendof Figure 2.

ing from 174 to 216 megacycles, an antenna de- Figure 5 1S a Perspective exploded detafl View signed for maximum eiliciency at the mean freshowing the method employed for clamping quency of the lower band would notprovide satiscross-bar 0 a Vertical pp in the assembly factory reception except in cases where the reof Figure 2. ceiver was located fairly close to the higher fre- Figure 6 is a side elevational view of a relay quency t tion Sw p y d n t e System of Figure 1. The present invention aims to provide an an- F e 7 is a cross-sectional view taken on line tenna system employing individual elements, 1-1 of Figure 6. each designed and directed for optimum reception of a particular station serving the area in which the receiver is located. The present invention contemplates that three such elements will be sumcient to more satisfactory reception for a receiver located in any area where television service is available.

Relei'i'ing now to the drawings, Figure 1 illustrates schematically the input circuit of a conventional television receiver. Designated at H is the input transformer of the receiver. The input circuit of the receiver may be tuned at the secondary of transformer II by means of a pluraiity of nxed capacitors Cl, C2, G3 which may be selectively connected across the secondary by means or a movable switch arm l2 in a manner well known in the art. Connected across the condenser C3 is a shunt coil |3for substantially increasing the resonance frequency of the input circuit, as where it is desired to tune the receiver to a channel in the upper television band. The signal is fed to the grid M of a mixer tube l5 through a, coupling condenser l5.

Designated at H is the oscillator tube the tube being grid-tuned by a coil l8 across which may be connected any one of a plurality of adjusted'capacitors C4, C5, C5 by means of a movable switch arm l9 mechanically hnked to switch arm H in a well-known manner. A fine tuning condenser is connected across a portion of coil l8. The cathode 2| of tube I1 is connected to a grid 22 of tube I5, whereby the output sig- 4 reflector 39, in which case cross-bar 38 will be suitably shortened in length. The orientation of the folded dipole 25, may be adjusted in a horizontal plane by rotating support to move the dipole to a broadside position normal to the direction of the transmitter to be received and securing support 35 in this position by means of a set screw on the top arm of bracket 32. The antenna assembly 25, 25' may be adjusted ma vertical planeby angularly adjusting the clamping brackets 31, 31 around the axis of the bolt which secures them to the flattened top end nal of oscillator tube |l may be mixed in tube IS with the input radio frequency energy derived from the input coil The circuit heretofore described is entirely conventional and forms no part of the present invention.

The antenna lead-in wires are shown at 23 and 24 and are connected to the primary of the input transformer Designated generally at 25, 25', 26, 26 and 21, 21' are the respective dipole 36 of vertical support 35..

The ends of the folded dipole element itself are secured to a bar 4| of di-electric material, said bar being secured at its intermediate portion to a flattened upstanding lug 42 formed at the end of cross-bar 38, as shown in Figure 3.

Secured to the end portions of horizontal sup ports 33 and 34 by vertical axial securing bolts 33' and 34' and rotatably adjustable thereon around the axes of said securing bolts are short upstanding post members 43 and 44 having flattened top portions to which are adjustably secured opposing pairs of clamping brackets 31, 31 clamping the cross-bars of the respective antenna assemblies 26, 25' and 21, 21. The general structural features of the antenna assemblies 25, 26'

and 21, 21' and 25, 25' are similar except that each antenna assembly is dimensional in accordanc with thewave length of the channel to be received so as to provide optimum efliciency of reception thereof. The length of each folded dipole will be approximately nine tenths of the length of one half a wave length taken at the center frequency of the desired channel. The design of the antenna assemblies per se is wellknown inthe art.

elements of three different antenna assemblies subsequently to be described in detail.

A relay switch, shown generally at 28, is provided at the antenna to selectively connect the lead-in wires 23 and 24 to the different antenna assemblies. Switch 28 is remotely controlled at the receiver by a movable switch arm 29 which is mechanically linked to the channel-selecting switch arms I2 and I9. As shown in Figure 1, switch arm 29 is connected to the hot side-of a conventional low voltage power supply 30 pro vided at the receiver, which may be part of the regular receiver power supply system.

For simplicity of presentation in Figure l the antenna assemblies are illustrated as ordinary dipoles. However, in actual practice, it is preferable to employ antenna assemblies of the folded dipole multiple-element type, such as are disclosed in Figures 2 to 5.

Referring now to Figures 2 to 5, 3| designates the main antenna supporting mast. Designated at 32 is a four-way coupling bracket secured to the top of mast 3|. Secured to the horizontal arms of bracket 32 are horizontal supports 33 and 34 and secured to the top arm of bracket the horizontal di-electric tie strips 4| and the cross-bar end lugs 42. The upper arms of the folded dipole elements are clamped to the top portions of the vertical strips by brackets 46.

It is thus apparent that each of the folded dipole assemblies 25, 25', 26, 26', and 21, 21' is dimensioned in accordance with the mean. frequency of the channel to be received and may be oriented in accordance with the direction and polarization of the individual television transmitters to be received.

Referring now to Figures 6, 7, and 8, the relay switch 28 comprises an elongated housing 41 of suitable di-electric material having a removable end portion 48 and provided with a, removable cover plate 49. Secured in the side walls of the w and in the cover plate 49 are opposed pairs of contact prongs 52, 52' and 53, 53. The prongs 50, 5|, 52 and 53 are in a common transverse plane and the prongs 50', 5|, 52' and 53' are also in a common transverse plane.

Pivoted at 54 in the intermediate portion of housing 41 is an armature 55 of di-electric material. One end of armature 55 is connected by a coiled spring 56 to a di-electric block 51 secured within the housing end portion 48, biasing the o armature 55 to the centered position shown in Figure 7.

Secured to armature 55 in the plane of each desired, a director may be employed in place of connected together by their securing rivets 60.

amazes The contact members 58 have intermediate raised portions 5| of substantial length, said raised portions being constantly respectively engaged by the inner ends of the respective contact prongs 53, 53'. The contact members 59 have intermediate depending portions 52 of reduced length, said depending portions 62 being respectively engaged by the inner ends of the respective contact prongs 52, 52' only when the armature 55 is in its centered position. At their left end, as viewed in Figures 7 and 8, the contact members 58 and 59 have spaced resilient fingers 53 and 54 and at their right ends have spaced resilient finger 55 and 55. When the armature 55 is rotated counter-clockwise, as viewed in Figure 7, the respective pairs of contacts 58, 59 engage the inner ends of the respective prongs 50 and 50', establishing connections respectively between prongs 53' and 50' and between 53 and 50. Similarly, when the armature 55 is rotated clockwise, connections areestablished between contacts 53' and 5| and 53 and 5|. In the center position of the armature, connections are established between contacts 53' and 52' and between 53 and 52.

Thelead wires from dipole 25, 25' are connected by suitable plug connectors to the prongs 52, 52'. The lead wires from dipole 25, 25' are similarl connected to prongs 5|, 5| and the lead wires from dipole 21, 21' are similarly connected to prongs 50, 50'. The lead-in wires 23 and 24 are connected in'a similar manner to the prongs 53, 53'.

At its opposite end, armature 55 carries a soft iron cap 51. Secured in the housing 41 on opposite sides of cap 51 are suitably shielded electromagnets 68 and 59. One terminal of each of said electromagnets is grounded to the shield thereof. The other terminals of the electromagnets are connected to the jacks of a dual female plug secured in the end wall of housing 41. A suitable shielded two-conductor cable is provided having a male plug received in female plug III.

The wires of said cable, shown at 1| and I2 are connected to respective stationary contacts 13 and '14 in the receiver engageable by the switch arm 29. The cable shield is connected to the shields of electromagnets 69 and 58 and is grounded at the receiver.

With the channel-selecting switch arms I2 and I9 in the positions shown in Figure 1, switch arm 29 does not engage either of the contacts I3 or 14. The electromagnets are therefore both deenergized and armature-55 is in its centered posltion. Dipole 25, 25 is therefore connected to the lead in wires 23 and 24 in this first position of switch arms I2 and I9. When switch arms I2 and I9 are moved to their next channel-selecting positions, switch arm 29 engages contact I3, causing electromagnet 58 to be energized from the power supply 30. Armature 55 is therefore rotated clockwise, as viewed in Figure 7, opening the lead-in circuit at the contact depending portions 52 but closing a new circuit by the engagement of the resilient fingers 55, 56 with the respective prongs 5|, 5|. This connects dipole 25, 25' to the lead-in wires 23, 24. When switch arms I2 and I9 are rotated to their third channel-selecting position, switch arm 29 engages contact I4, causing electromagnet 59 to become energized. This rotates armature 55 counterclockwise, as viewed in Figure 7, engaging the respective pairs of resilient fingers 53, 54 with the respective prongs 50, 50', and thereby connecting the dipole 21, 21' to the lead-in wires 23, 24.

6 It is thus seen that the action of selecting a channel at the receiver automatically operates the three-position relay armature 55 to connect the associated antenna element to the receiver lead-in wires.

Figure 8a shows a modified form of the threeposition antenna selecting relay wherein the prong elements, shown respectively at I50, I5I I52 and I53 are removable, so as to be readily replaceable in case of wear. The armature 55 has secured thereto solid contact bars having respective end fingers I53 and I55. Said contact bars have upper raised portions I6I of substantial length and central depending contact lugs I52. The respective prongs are provided at their inner ends with resilient contact springs I54, I54. As shown in Figure 8a, the contact springs carried by prong I53 engage the raised portion I5I. In the centered position of armature 55, the contact springs carried by prongs I52 engage the contact lug I52. When the armature is rotated by the energization of one or the other electromagneh'as above described, the circuit is broken at lug I52 and is closed either at fingers I55 or I53 by engagement with the springs I54,

-I54 carried by either prong I5I' orprong I50.

The operationof the modification shown by Figure 8a is otherwise similar to the previously described form of the invention.

'various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is: i

1. In combination with a television receiver having a multi-position channel selector, an antenna system comprising a plurality of individual antenna elements, each element being associated with one of the channels selected by said channel selector, an electromagnetically-operated selector switch at said antenna system having a pair of movable contact members and respective pairs of stationary contacts connected to the respective antenna elements, a pair of lead-in conductors connecting said movable contact members to the input circuit of the receiver, and means at the receiver mechanically coupled to said channel selector for selectively energizing said selector switch responsive to the actuation of the channel selector.

2. In combination with a television receiver having a three-position channel selector, an antenna system comprising three individual antenna elements, each element being formed and arranged to receive with maximum efficiency one of the channels selected by said channel selector, a selector switch at the antenna system comprising a pair of movable contact members and three spaced pairs of stationary contacts selectively engageable by said movable contact members and connected to the respective antenna elements, means connecting the movable contact members to the input circuit of the receiver, means biasing said movable contact members into engagement with one set of stationary contacts, electromagnetic means for selectively moving said movable contact members into engagement with the remaining pairs of stationary contacts, and means at the receiver mechanically 7 a coupled to said channel selector for selectively energizing said electromagnetic means.

3. In combination with a television receiver having a three-position channel selector, an antenna system comprising three individual dipoles, each dipole being formed and arranged for optimum reception of one of the channels-'selected by said channel selector, a three-position relay at said antenna system, the respective dipoles being connected torespective pairs of stationary contacts of said relay, the relay armature carrying a pair of contact elements se lectively engageable with said pairs of stationary contacts, means connecting the said contact elements to the input circuit oi the receiver, means biasing said armature to a position wherein said contact elements engage a first set of stationary contacts, a first magnet coil in said relay, 9. second magnet coil in said relay, and means at the receiver for selectively energizing said magnet coils, said latter means including a movable switch arm mechanically coupled to the channel selector and stationary contacts in the energizing circuits of the respective coils and engageable by said switch arm, the armature being movable responsive to the energization of the first magnet coil into a position wherein said pair of contact elements engage a second set of stationary contacts of the relay, and being movable responsive to the energization of said second magnet coil into a position wherein said pair 01. contact elements engage the third set 0! stationary contacts of the relay.

ARTHUR H. GUTSCHOW. CHARLES R. REESE.

REFERENCES CITED The tollowing references are of record in the file of this patent:

UNITED sTA'rns PATENTS OTHER REFERENCES Radio" June 1939, pp. 943, 74 and 75; ibid., October 1938. DD. 4244 and 76.

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