US2003372A - Directional receiver - Google Patents

Description

June 4, 1935A` l 'W.KH| EW1ND 2,003,372

DIRECTIONAL RECEIVER Filed Feb. 16, 1933 505mm A ATTORNEY lpafetedflune' 4, 1935 l i Walter Khlewindgerlin, Germanyyassignor i Telefunken Gesellschaft fur Drahtlose Tele- -Y graphie m. fb. H., Berlin, Germany,` a corpora-j i Y :e 4tion, of Germany l l f Application February '16, iseaserial No.` 657,069

z 1 .i l InGermany April 1, 1932 e K n SClanis. [This inventionrelatesto-a'methodof and arrangement for ascertaining direction in taking bearings 4of electro-'magneticwaves.` .In order toi ascertain furthermore the sense' t 5 ofrdirectionof electro-magnetic rays for'which bearing has already `been established by means "of a iframe antenna, itvis a customary methodV to use alinear auxiliary antennawhose voltage is combined `in l such mannerA 'with that supplied 'by thedirective antenna, that the directional receiving characteristicassumesthe shape zof a cardioid.` In order to. determine` thesense of direction, the directive antenna is placed iinto the position-in vvhichathe` reception is a maximum i reception.` With this position-corresponds the f point of the cardioidV for which `the vreception is at maximum oriminimum in accordance with the relative sense of connection of the two an-` tennae. By alternately connecting` the auxiliary antenna to the lone or theother pole of the directional-"antenna or i of the circuit `sup1`)lied= by the'latter itcan be determined'by such experi mentation bywhatever connection th'eV signal 4.5; by a corresponding'V reversal of alswitch.

strength becomes greater thuslascertaining the sense of direction'of thedirectiverays. i.

l In connecting` the auxiliary antenna'to the one or the other pole of thedirectional 'antenna or to aY circuit supplied by .the latter l(such connec-' tion may either .be adirectone or it may include a special amplifier) dilculties arev beingmet in that thecapacity of theauxiliary antenna andof its in,putl connections often cause a consider able detuning` of the circuits which` previously' had been accuratelyrtuned forthe direction find-1 ing by means `of the framel antenna alone.

` Accordingto thep'esent invention this flavrl.` back .is overcome inv that-the auxiliary antenna` is :continuously coupled to th'e input circuit of two `amplifier ltubesgeach of whose output cirV 1 cuitsare continuously connectedrespectively to` one of the poles ofthejdirectional antennaor of' the V*circuit supplied by the latter, and that for as-i certaining the direction the one or the other ofi ,the ampliiiers is rendered electrically eiiective l This invention isbest `described by referring Vto' the:accompanying` drawing in which,`

``Iig.` 1 is aischematic-cir'cuit diagram of ione embodimentl ofv this invention;

pointersygiV f Figif is a soin-:maticV circuit ldiagramrof another embodiment of this invention wherein the i' directive antennais formed of two` open vertical conductors instead of theframe or loop` antenna shown nFg. Y1.; m Q f1 '.7 Figure 1 shows a schematic illustration. of an embodiment of the arrangement according to the Y,

invention by way of example. Herein is aF-a 1ig.2` is'a.plan view of `the'loopoperating hand" wheel indicatingscale pointer and 'two auxiliary-l (olyesoV-in Y frame antennaeis the-tube of the input stage v of the receiver; b represents the linear auxiliary i antennadl, d2 are two ampliers,*-H+H" are the lpoles' of alamentheating battery, hrand 71,2.`

respectively are the heating'resistors and'vsfdesignates a switch. VThe auxiliary-jantennais con?. tinuously coupled with Vthe grids connected in' parallel of the two amplifiers 011,112. f The 'anodes of the amplifiers are connected tothe polesLrZ` 1'0? across condensers C1, C2. `.Changing potentialsfor theV anodesof tubes d1, vcl2 is supplied from a. source ,-l-A. If the auxiliary antenna'is not used;- (for instance during ...direction lndinghwith only-V the frame antenna) the switch s is in the center two amplifiers are in inoperative position.;

position. The heating Lis disconnected anctrthe `For ascertaining theV direction theV switchI S is 1 several times alternately moved to theleft fand" right whereby the one or.` the other of the amplif-V iiers becomes alternately eiiective'throughclos-f ing of the heatingcurrent so that the auxiliary antenna isalternately combined with the frame antenna in equal phase or in opposite, phase.'

TheY conditions, of tuning are thereby notV changed as the two `tubes di and d2 were also pre-I viously connectedlto the poles l and" I f By means ofthe switch'snot only .the 'activa-li tion of the ampliersfdi; d2` can be obtained but also the control of vthe power thereof due to the adjustment or" the heating resistors.

spectiyely ofthe.` amplifiers besides the method of connecting the heating, could also be obtained by meansof connectinglor varying)l or con-2` trolling respectively thegrid bias oranodep'otential while the heating is connected. AI

Which, Vthe switch passesfduring its movementzto the left orhright, with suitableimarkingsby 'which' cilitated vso that the switch sY can beused-at the same' time as indicator` for the sense of' directiom kA suitable and often usedA method 'of marking consists in that the two surfaces are marked l:by vvarious colors forV instance the left eld iblue andthe right ,field in' red.A Two auxiliary point@ ers B and R fastened on the direction indicating4 wheel P correspond with these`markingsin`th`at one is marked in blue and the otherlinf red.'v These pointers are adapted to be displacedfatlan angle ,of 90"A with respect to the main'dire'ction over adirection indicating scale U. I Y During bearing by means of the framefan-J` tenna A; only, thesameis'placed Vinto therpofsi- It is obvious that the activation or." control :re`"

the recognition of the sense of direction isa-'f indicating pointer Z, likewise fastened on" the direction iinding wheel and adapted to be moved It isV advisable to providel the surfaces 'throughv tion inawhich the reception'is a minimum recept.,

tion. If hereby the Amain direction indicating pointer-Z points at the calibration `0Vof thescale.

U itV Will be recognized that the directive ray forms with the direction determined by the iixed zero line. ofthe scale anV angle of a or an angle (M4-180). In order to 'determine the sense of direction the direction indicating wheel is moved in either direction approximately 90,V so that either'the blue auxiliary pointer B or theV redauxiliary pointer R is above the indicating line for Ythe angle a of the scale. The' blue auxiliary pointer may be assumed to be at this position. Now, the switch s (see Figure i) will be moved Y alternately several times to theyleft and the right the angle (c4-180).

resistances h1 and hzvand will -beleftto'remain upon the eld for which the signal strength is the greatest. VIf this is the field marked blueY then the sense of direction corresponds with the position ofthe blue auxiliary pointer B' i. e. .with the. angle a". In the other case i. e'. if the greater signalV strength occurs at the positionV of the vpointer abovethe red iield, theV sense yof direction,4 offthe directive rays corresponds with the position of the Vred rauxiliary pointer E, i. e. with Inthis manner .the "switch s can time be used as -an indicator for the recognition of the sense ofV direction. y

Itis obvious that itis Within the' same spirit ofthe invention: if as directive antenna instead of a closedvframe anV antenna ormed in any other way, ,is used', such as an Adcock-antenna.

'An.embodimentA of this'type is shown in Fig-, ure 3 by Way of example. The directiveantenna is formed-'of two open vertical conductorsad, whichl are preferably arranged movable about a symmetrical axis between these conductors.

- They two conductors da of the directive antenna are connected to .the intermediate circuit by means of coupling transformers Ick and which circuit suppliesthe input circuit of the Vhigh fre- Vquency ampliiierY e which forms the irst stage ofthe receiver.

The auxiliary antenna bis ar'- rangedat the center between theconductors ad. Otherwise rthe circuit for the auxiliary antenna corresponds with that of Figure 1.

It :is advisable in particular when operating with very short waves to provide the arnpliiiersVV didz with screen grids as shown in order to' prea. non-symmetrical signal absorption member, av

thermionici tubeconnected `therewith by way of ftunng means, and means vfor determining the sense of direction of received signals comprising arp'airY of thermionic tubes having'Y their anodes connected. to different sides of Ysaid absorption member, their control grids connected to a nondirection aerial, and means for alternately, rendering said last named tubes operative `and inoperative. Y Y

2i `Direction and sense of direction determining absorption system comprising, a directive aerial system, a Ynon-directive aerial, a pair of'thermionicy tubes having their-input electrodes connected to. said non-directional aerial, rand a connection between each terminaloi said directive aerial and they output electrode in one of'said tubes. y

3'. A direction finding system comprising inv combination a loop aerial connected to a thermionic., tube having input and output circuits, a non-directional aerialV continuously coupled with at the same theinput circuit of Vtwo thermionic tubes having the output" of each oneof said tubes continuously connected tofopposite Asides of said loop aerial, means to determine the sense of direction, said lmeans controlling the activation` ofreither one of said thermionic tubes which arecoupled with said non-directional aerial.

4. A direction nding system comprising in combination a loop aerial connected to a thermionic tubehaving input and output circuits, a non-directional aerial continuously coupled with .the input circuit of two thermionic tubes having the output of each one of said Atubes continuously connected to opposite sides of said loop aerial, means to determine the sense of direction, switching means comprising 'a'fcommon switch arm and separate variable resistance elements f to. Vvary the heater voltage of either one of: said thermionic tubes which are coupled with said-non-directional aerial;V

5. A direction nding `system"co-mpri'singin combination a loop aerial' connected topa thei'-,r mionic tube havingxinput and output circuitsfa non-directionalaerial continuously coupled with the input circuit ofvv two screengrid tubes'having' the Youtput of each one of-jsaid tubes continuously connected-to oppositeV sides: of said loop aerial, means to determine .thesense of direction, said means controlling the activation 'of either one ofsaid screen gridtubes which arecoupled with the non-directional aerial.

f6'. A directive antenna system comprisingtwo openvertical conductors, said conductors arranged to'be movable about a symmetrical axis between said conductors, transformer.- coupling.

Vertical conductor: couplings, means to detervmine thesense of direction, said means controlling theactivation ,ofeither oneof said screen grid tubes.V

7; A directive antenna'system'comprising two open verticalconductors,V saidconductors .ar-

ranged to be movable abouta symmetrical axisy between'said conductors, transformer coupling means for coupling said.conductors'toV the input circuit of a high frequency receiver: amplifier,y an auxiliary antenna continuouslyvr connectedv with the inputV circuit of two screen grid tubes havingY theV output of each one of said tubes continuously `connectedY to oppositesides. ofsaid vertical conl vductor couplings, means'to determine the sense ofv direction, switching` means comprising a com'- inon'switch arm and separate variable resistance elements to vary the heater Voltagelof: either one of said screen grid tubes'v which arel coupled with the vertical conductorsf f' 8.` A direction iinding 'system'comprisingv in combination a loop aerialconnected to a thermionic tube having input and output'v circuitala non-directional aerial continuously `coupledw'ith the input circuit of .two vthermionic tubes'having the output lof each one of saidv tubes continuously. connected across condense'rs to opposite sides1of said loop aerial, meansto determinerthevsen'se offv directiongi said means controllingthe activation of either lone of said thermionicltubes'which-arecoupled with said non-directionallaerial. 1 j

. WALTER Kmlnwmni '1 1

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