Патент USA US2026123код для вставки
31, i935. l B. |_. DOLBEAR 2,026,123 IMFRQVED DIRECTION FINDER BALANCER Filed Jan. 18, 1952 £52519 24 75 \ 22 Z 4 7 75 H754“ ,5] /0/2/17/20 75 ATTORNEY 2,026,12á Patented Dec. 31, 1935 UNITED STATES PATENT oI-‘Flcia¥ 2,026,123 IMPROVED vrnlnno'rl'o'iii FINDER. BALANCER' Benjamin L. Dolbear, Belmont, Mass., assignor to Radio Corporation of America, a corporation of Delaware Application January 18, 1932,V Serial No. 587,325 6 Claims. (Cl. 250;-11) This invention relates to improved radio direc tion finder balancers, and more particularly those used in the higher frequency circuits. An object of this invention is to simplify and 5 improve direction finder balancers. A further object of this invention is to simplify and so arrange the devices which are associated With a capacity balancer that the maximum effl The invention consists of various other features and methods of construction as describedV and illustrated in the accompanying drawing. In the - drawing like references refer to like parts, of which- l 5 Figure 1 is a plan view of the assembled devices; Fig. 2 is a vertical section of Fig'. 1,V the section' being taken at line 2_2; ` ’ Fig. 3 is an elevation ofFig. l; ciency may be obtained when using such an ar 10' rangement of parts in the higher frequency direc Fig. 4 is a partial direction finder circuit show- 10k ing that portion which relates to' this invention. The simplified and improved direction finder balancer is shown >in Figs. 1, 2 and 3, wherein tion finder circuit. Likewise, such an arrange ment also results in a minimum'number of essen tial parts and thereby reduces the cost of manu A feature of this invention is the combining of a sense resistance and a capacity balancer and by an arrangement of a pair of contacts in such a manner that the rotaryY plate, which is an im the base I is of “bakelite dilector” or other good insulating material of low dielectric loss. Mount- 15 ed upon this base is a central bearing' or bushing 2 which is held in position by the bearing `-nut 3. An operating shaft 4 is provided with an insu portant‘element to this invention, may actuate 20 the contacts mentioned above and thereby place latedknob, 5, and a pointer 6, and locked to the shaft by means of members 'I6 an-d 'I'I.V 0n the 20 _ ß facture of such devices. 15 Y the sense resistance in series with one side of a loop when desired to determine the sense of direc tion from which a signal is coming. ' It is well known in the ‘art of direction ñnding 25 that voltages induced in the loop from sources other than theA distant radio transmitter, such as the transmitter energy picked up and reradiated from nearby wires or any other conducting objects produce the same effect as unbalanced symmetry opposite end of the shaft 4 is mounted a single rotary condenser plate 'I which is held securely in position by means of a nut 8, a collar 9, and rivets I0, Il, I2 and I3. A springl‘IZ provides proper friction for the shaft. Directly below the 25 rotary plate l, but spaced about one thirty-sec ond of an inch, there are located two fixed plates @Li and I5 respectively, each of . whichare of _ the minimum a capacity balancer is connected to equal area and spaced an equal distance from the center of the rotor shaft 4'so that the ca- 30 pacity >of each plate will be approximately the same Vwith respect to the center ofthe rotary plate 'I when it is in a horizontal position. TheseV fixed plates I4 and I5 are securedtothe base I 35 each side of the loop to' balance out any dissym metry occurring when the loop is rotated. I have by means of metallic supports I6, Il, I8 andIB, 35 and fastened by means' of screws _20, 2|, 22, 23, ‘ 30 of the loop receiving circuit. Such unbalance or distortion prevents the operator of a direction finder from obtaining a well defined and sharp minimum or null point. Therefore, to improve found that in a radio direction finder employing the higher frequencies in the order of 1500 to 30,000 kilocycles or short wave lengths, that it is 40' desirable and often necessary to shorten and pre vent sharp bends in the leads or wires connecting the plates of a capacity balancer with those of the sense resistance and its associated sense . switch. I therefore reduce in number and shorten 45 the wires connecting the loop and the balancer, and also those of the sense resistance, by assem bling the sense resistance and the sense switch on a single insulating member. I further arrange the contacts of the senseswitch in such a manner 50‘ that the operating knob of the capacity balancer also serves to operate the sense switch. I am so able to arrange these latter parts for the reason that the capacity balancer is not used when Van A ,_ indication o_f the sense _of direction of the received 5‘5- signal is to be obtained. ' ' £4, 25, 26 and 2l. A fie'xiblelead 28> is Vsecuredto ~ the rotar-y plate shaft which in turn connects by means of >a backstop spring member V‘I5 tothe `sense switch contact 29. -A'relativêly short con- 40 necting strip 30 connects the contact29 with the . terminal screw 3|, Vwasher~aridnut 32> and 33. The other contact 34 of the sense switch is con“ nccted by means of a strip 35 to a clip 36, pro-' viding the mounting of the sense resistance 341. 45 K The other sense resistance clip 378 isY connected to the ñxed condenser >plate I5 by a lead 40 and thence byV another lead VIII to the terminal screws 42,k washers 43, and nuts 44. lThe other 1 fixed plate I4 is connected from the screw 422 50 by meanrsof'a lead 45. to the terminal screw 4_6., washer 4l, and nutI 48. The base I is' further provided with’rsuitable apertures 49, 50, '5I 52, for mounting thejdevice on the panel ofthe direction finder receiving apparatus.l 55 2 2,026,123 , trically connect said sense antenna in series with said resistance which is electrically connected on Referring now to Fig. 4, a wiring diagram of this device is enclosed within the dot and dash line, also the external parts of the circuit are included, which have not been previously men tioned. There is shown a loop 53, grounding condenser 54, ground 55, sense antenna 5B, tun ing condenser 51, vacuum tubes 58 and 59, with one end to said fixed contact and on the other end to one side of the loop to indicate the sense of direction of an incoming wave. 2. In a radio direction'finder capacity balancer for an open and closed antenna system compris ing a loop antenna, a sense antenna, said ca input grids 60 and 6l, filaments G2 and 63,'with ñlament rheostat 64, and battery 65 which in 10 dicate the filament supply for the vacuum tubes pacity balancer having a fixed plate electrode connected to each side of said loop antenna, said 10 58 and 59, plates 66 and 61 which form the input ” capacity balancer having mounted on a common of a `superheterodyne receiver 13 comprising a base a rotary plate having a central shaft, said ñxed plate electrodes oppositely disposed in re local oscillator 14, ñrst and second detectors 68 and 69 respectively, and a sufficient audio stage ' spect to the shaft of said rotary plate, a pair of spring members having relatively nxed and mov 19 to Igive the desired signal strength for the phones 1l. “t” . . . able contacts, the movable contact being elec . trically connected to the rotary plate and posi In the operation of this improved balancer the operator first sets the pointerß on zero, which is a position wherein each of the ñxed plates I4 and l5 are covered by the rotary-'plate 1 by sub Ytioned adjacent said shaft to make an electrical connection with the relatively ñxed contact by means of the edge of Vsaid rotary plate moving the movablecontact toward said relativelyfixed contact when saidY rotary plate is rotated in a _stantiallycan equal area. Then assuming a bea con station is being received, by listening in the phones 1I he carefully sets the loop 53 at a po sition of minimum signal response. VThe knob 5 l0 Cil 30 position'beyondthe area of at least one of the fixed plates> soV as to ‘electrically connect said is then rotated slowly in each direction until a position .is found that will Yfurther reduce the strength of the signal. It then may be neces sary for him to obtain a more accurate setting by sense antenna Vin series with a resistance which 25 is electrically connected on one end to said ñxed contact and to one of said fixedplates on the other end so as to be connected in series with slight readjustment vof the loop and then again one side of said loop to indicate the sense of di rection of an incoming wave when said contacts 30 the balancer. This position will be the line po sition of the received signal, >and unless the op are 35. . ' an open antenna, a closed antenna, said closed ahead yofor behind him. Therefore,Y with the loop remaining in the position of minimum signal response mentioned above, the operating knob relatively fixed andmovable contacts `and a re 5 is rotated as far as possible, toward the con sistance mounted on a base, one side of said re sistance being electrically connected to at least one of said fixed plates and said closed antenna, each side of said closed antenna electrically con nected to one of »the oppositely disposed fixed Vsition the sense resistance 31 is then placed in series with the sense antenna and .one side of the loop 53. The loop is then rotated through 90 degrees from the null point and rthe _operator thennotes whether the signal increases or de plates, said rotary plate being electrically con nected to said relatively fixed contactand said response will indicate the direction from which said lmovable contact by means Vof the edge of said rotary plate moving said movable contact toward said relatively fixed contact so that the open antenna, means for electrically connecting 45 creases in strength. The position of increased. the otherside of «said resistance to one side of the signal is coming. 50., , antenna having in'combination a capacity bal ancercornprising a'rotary plate and a pair of 35 oppositely disposed ñxed plates, a switch having tact 29. In this position the rotary plate 1Y will close the contacts 29 and 34 and in such a po 4,5 closed. 3. In anni-lateral receiving circuit comprising _erator knows the approximate source of the sig nal in respect Vto his position, he Will next ñnd it necessary to determine whether the signal is Y Y Although this invention has been described as embodied in a particular form and arrangement of parts, it Vshould be understood that it is ca pable of embodiment in other and diíîerent forms within the spirit and scope of the append ed claims. ' . What I claim is: 1. In a _radio direction finder comprising a sense antenna, a IOQD, a capacity balancer having mounted upon a common insulatingbase a cen tral bearing for a rotary plate, a resistance, a 60 pair of oppositely disposedïñxed plates, a plu-`< rality of Yupwardly extended support posts for supporting said pair of fixed plates'which are con nected to one side _of said loop and are oppositely disposed in respect to the shaft of said rotary plate, a pair of upward extending-spring contact members having relatively fixed and movable contacts, the movable contact electrically con resistance and said open antenna are connected in series with one-side of said closed antenna to indicate the sense‘of vdirection of the ‘received - energy. ' 4. A radio direction finder capacity balancer for an open and 'closed antenna system including 55 a loop and an open antenna, comprising an Vin sulated member for-mounting a rotary plate, a shaft for rotating said rotary plate, a pair of fixed plates each` of which are connected to said loop and oppositely disposed in respect-to the shaftof said rotary plate, a resistance located onrsaid> insulated member, relatively ñxed and movable springï contact members arranged on said insulatedV member to make and break elec trical contacts, atleast one of said contacts being , connectedto one side of said resistance, the other side of said resistance being connected to one of said fixed plates Vand said iixed contact mem nected to said sense antenna and the rotary plate and being arranged on the base at right angles to ber, said other contact’ being positively connected 70 each >of said ñxed plates and positioned in the .toY said rotary plate and intermittently to said path of said rotary plateso as to make electrical openantenna by means of said rotary plate mov connection to the relatively fixed contact when ing in a path so as to close said contacts for the rotary plate is rotated past the `position be- - electrically connecting in series said open an yond the active capacity area ofat least one of tenna with one side of s'aid loop, for indicating e theñxed plates to close the contacts and to elec the sense of direction of an incoming wave. w c 3 2,026,123 5. A uni-lateral receiving energy responsive sense antenna, a loop, a capacity balancer having circuit comprising a closed antenna and an open a base` on which is mounted a rotary plate, a re~ antenna, said closed antenna forming a circuit, a sistance, apair of oppositely disposed ñxed plates, resistance and a switch, said switch having ñxed l said ñxed plates being connected to each side and movable contacts, a pair of ñxed condenser plates substantially of the same area, each of said fixed plates being connected to one side of said closed antenna, and a rotary plate connected to the open antenna circuit and to said movable contact on said switch, the fixed contact of said switch being connected to one side of said re sistance, the other side of said resistance being connected to at least one of said ñxed plates, means for closing said contacts to provide con nections to one side of said closed antenna, the resistance and said ñxed contact for placing said of said loop and are oppositely disposed in re spect to the center of said rotary plate, a pair of contact members one of which is electrically connected to said sense antenna and the rotary plate and arranged on the base at right angles to each of said ñxed plates and positioned in the path of said rotary plate so as to make electrical connection by closing said contacts when the ro tary plate is rotated past the position beyond the active capacity area of at least one of the ñxed plates to electrically connect said sense an tenna in series with said resistance which is resistance in series with said open antenna cir- s electrically connected to one of said contacts, cuit When said plate is rotated to an unbalanced and the other end oi said resistance being con position in which said rotary plate substantially nected with one side of said loop- to indicate the covers only the area of one of said fixed plates sense of direction of an incoming Wave when»20 to indicate the sense of direction of energy re sponse. 6. In a radio direction ñnder comprising a said rotary plate closes said contacts. BENJAMIN L. DOLBEAR.