. The Bell System technical journal . ticial line was loaded wiili iron dust corecoils which served the purpose admirabh. not oiiU- as regards in-ductance and alternating current resistance but also as distortion. Iron dust is, of course, very different in itsmagnetic characteristics from permalloy. However, owing to iIn-large number of turns on a coil, it is operated u mwU liighcr heldstrengths and on a part of the magnetization cur\c correspondingapproximately to thai at which permalloy is operated on the ca-ic for magnetic distortion was in fact .i little worse wi
. The Bell System technical journal . ticial line was loaded wiili iron dust corecoils which served the purpose admirabh. not oiiU- as regards in-ductance and alternating current resistance but also as distortion. Iron dust is, of course, very different in itsmagnetic characteristics from permalloy. However, owing to iIn-large number of turns on a coil, it is operated u mwU liighcr heldstrengths and on a part of the magnetization cur\c correspondingapproximately to thai at which permalloy is operated on the ca-ic for magnetic distortion was in fact .i little worse with the nil: si .171 artilicial lint- witli the tluii |)r()p()st(l 1^. ) sliows a photi)-graph of the artificial liiu, tlie roils of wliicli arc in tin- larj^c ironjxits and the resistance and paper condenser capacil> units of whichare in the steel cases. This line was e(|ui\alent to a ) nauticalmile calile loaded with M) millihenries per .ind o\(,r it leKil>I<. Iig. 5—Luailitl Artificial Lint- signals were secured at speeds up to more than 2,GOO letters perminute. Such a sfieed of operation was quite beyond the range of thethen available telegraph instruments, and accordingly special transmit-ting and receiving instruments were required. The multiplex dis-tributor of the Western Klectric printing telegraph system provedan excellent transmitter for experimental purposes and, for receiving, 372 BELL SYSIEM TECHNICAL JOURNAL use was made of a rdinlurud xacuiiiii Uibe aiiiplitier and signal shapingnetwork, the signals being recorded on a string oscillograph. Fig. 6shows part of a test message received over the loaded artificial cableat a speed of 2,240 letters per minute. The results of the tests with the artificial loaded cable were en-tirely in agreement with our (■.•ilrnlatinn-; anri showed iliat it was
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
