77//; /.(>. »/)/;/) S( It.M.IRIXr. Tl.l.lCKAl'll C.IHI.I- 



.V.7 



hisht'st frtMiiK-nry ru'»i'ssar>' to m.iki- tlu- siv;iials li-nil)le is rccfivccl 

 with siiHuii'iU amplitudi' to salVly override the siifjerposetl inter- 

 ferenri-. Just what tin- rchitioii of tliat friciuiiuy is to the speed of 

 sij^naUiiiv; cannot l)e detinitel>' stated, sinie it depends on the nietliod 

 of operation and code emplo\ed as well as on the doired perfection 



20 



30 40 50 

 CYCLES PER SECOND 



70 



60 



Kig. 4 — Received Current vs. l"rcquc-ncy. a. Non-loaded cable 

 cable, c. Real loaded cable 



h. Ideal loaded 



of signal shape. J. \V. Milnor '' has suggested that for cable code 

 operation and siphon recorder reception a fair value is about 1.5 

 times the fundamental frecpicncy of the signals, that is, the funda- 

 mental freciuency when a series of alternate dots and dashes is being 

 sent. 



r<iM.\RKs ON riiFi I)i:si(ix ()i- I,i).\i)i;i) (".\ni.i:s 



By referring again to the eciuation for a, above, it can now be 



explained why high permeability is a necessary characteristic of the 



* Journal A. I. E. F.., Vol. 41, p. 118, IPii, Transactions .-\. I. E. K., Vol. 41, 

 p. 20, 1922. 



