. The Bell System technical journal . F by-pass element minimiz-ing the loss of input signal power in the IV output network. In this designthe beating oscillator energy is introduced into the waveguide by mountingthe reflex oscillator tubes adjacent to the waveguide in such a fashion thatthe output probe is inserted into the waveguide cavity at a point removed byan odd one-quarter of a wavelength from the face of the TR output assures reflection of the local oscillator energy which travels towardthe TR tube directing it toward the crystal element. The degree of couplingof the reflex
. The Bell System technical journal . F by-pass element minimiz-ing the loss of input signal power in the IV output network. In this designthe beating oscillator energy is introduced into the waveguide by mountingthe reflex oscillator tubes adjacent to the waveguide in such a fashion thatthe output probe is inserted into the waveguide cavity at a point removed byan odd one-quarter of a wavelength from the face of the TR output assures reflection of the local oscillator energy which travels towardthe TR tube directing it toward the crystal element. The degree of couplingof the reflex oscillator circuit is varied by adjustment of the distance thatthe probe is inserted within the waveguide. For airborne applications anadditional oscillator tube is included for beacon reception. This basic form LOCAL OSCILLATORS & p^^^^^^r^^z^^ » ©^^-? rl W^^v/vl^^^^^^^^ u ^^--^-^--^^--^ ADJUSTABLECRYSTAL PISTON \ I cssmsssssussssis ESSSJ \\\\\\v\\\\:Tvr t mX 4 x^xmsssmsisssssxsiisi^ssssssxsiixs nX 4 COAXIAL ^^ INPUT FILTER H^. I-FOUTPUT Fig. 14.—10,000-mc Crystal Converter. Schematic diagram. of radar converter was employed in large numbers in the military airborneradar field during World War II. A third type of crystal converter design which was developed in the latterperiod of the war is illustrated in Fig. 15. A basic difiference in this struc-ture is found in the use of a waveguide hybrid junction often referred to as amagic tee. This junction has an electrical performance characteristicat microwaves similar to that of the hybrid coil common to low frequencycommunication circuits, , a 4-pair terminal network with an internalconfiguration such that power applied to any one pair of terminals will appearequally at two other pairs of terminals, but will not be available at the re-maining pair of terminals. Referring to Fig. 15, it should be noted thatpower applied to the input waveguide will appear equally in the outputbranches but is balanced out of the beat oscillat
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
