TY JOUR TI To the question of rail line maximum length determining at normal minimum value of insulation resistance in the function of the signal frequency of the rail circuit KW rail line KW rail circuit KW operating mode KW signal power KW frequency of signal carrier waves JO Transport automation research AU Leushin, V.B. AU Smirnova, L.B. AU Yusupov, R.R. PY 2018 IS 4 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"