. The Bell System technical journal . i n 1 21 j \l \z 2 1 // \ \ z 5 / A , / // / r \ 3 \ 2 / Oi ~ L 4 - 2 3 /, // 2 \ l/ / 2. I r -2 ^, _^ -3 --;/ Fig. 13—Transfer constants (T = ^ + iB)^ (1) of fixed terminal transducers, (2) of comparison transducers. (A comparison transducer consists of one mid-half section of the constant /& wave-filter and one of either i/-type, where ni = .6. Broken lines are for dissipation with Vk = ± .01 Uk). 316 BELL SYSTEM TECHNICAL JOURNAL Uu = — .92 in every branch, which range includes the useful part of abranch. In low pass and band pass wave-filters this tota
. The Bell System technical journal . i n 1 21 j \l \z 2 1 // \ \ z 5 / A , / // / r \ 3 \ 2 / Oi ~ L 4 - 2 3 /, // 2 \ l/ / 2. I r -2 ^, _^ -3 --;/ Fig. 13—Transfer constants (T = ^ + iB)^ (1) of fixed terminal transducers, (2) of comparison transducers. (A comparison transducer consists of one mid-half section of the constant /& wave-filter and one of either i/-type, where ni = .6. Broken lines are for dissipation with Vk = ± .01 Uk). 316 BELL SYSTEM TECHNICAL JOURNAL Uu = — .92 in every branch, which range includes the useful part of abranch. In low pass and band pass wave-filters this total rangecorresponds to 96 per cent of the theoretical band widths. From (31)there is a minimum y = .9857 at Uk = - .3696, and a maximumy = at = — .8297. Of course, other values of the parame-ters in this neighborhood would also be quite satisfactory. Theymight even be fixed by choosing the frequencies of infinite attenuationin the two half sections. But the above were taken in order to fix thefinal networks. -/.. zk/ lb, y WinffnM) _ R 2b, y= ^L = ^^-^_^^^ , {171=7250, rri^mn) iMg. 14—-Image impedance characteristics in the transmitting bands— (la, 1/)) of fixed terminal transducers,(la, Ih) of comparison transducers. (Broken lines are for dissipation with Vu = ± .01 Uk). The transfer constants of these fixed terminal transducers of are represented by the general attenuation and phase characteristicsof Fig. 13. Here also are shown the corresponding characteristicsof two comparison transducers, one of which is made up of a mid-halfsection each of the constant ^ and of the shunt .l/-type wave-filters and has the image impedances Wxk and PFu(w). The other,made up similarly, has the image impedances Wik and T4^2a(w). In ELECTRIC WAVE-FILTERS 317 both comparison transducers m = .6, this value of the parametergiving results which are representative of the best constant terminalimpedances possible in transducers with terminal M-types. (Thesecomparison
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