Spectra of a class of run-length limited MLT3 codes

A closed form expression for the lower cutoff frequency of a class of run-length limited versions of the MLT3 code has been found by extrapolation from a number of particular examples. MLT3 without run-length limiting has recently been selected by ANSI as the line code for a 125 Mbit/s LAN which uses copper building wiring. Towards the end of the debate possible modifications to include run-length limiting were considered but rejected for lack of information on their spectra. The authors give information which may be of use if MLT3 were considered for any future applications