TM 1-1510-225-10 3C-40 Table  3C-3  lists  the  VHF  NAV  frequencies  and corresponding DME channels.  The frequency is listed across the top and down the left side of the table.  This frequency    matrix    is    used    to    determine    the    DME channel.      For   example,   ILS-LOC  frequency  108.30 MHz is DME channel 20, VOR frequency 114.70 MHz channel 94, etc.  DME channels 1 through 126 listed in the   table   are   the   DME   X   channels.      The   DME   Y channels can be determined  from  the  table  by  adding 0.05   MHz   to   each   of   the   0.   1-MHz  columns.    For example,    ILS-LOC   frequency   108.35   MHz   is   DME channel  20Y,  VOR  frequency  E  114.75  MHz  is  DME channel   94Y,   etc.      The   126X   channels   and   126Y channels total the 252 DME channels available. Table 3C-3.  VHF Frequencies Versus DME X Channels 0.1 MHz VHF NAV (CTL-32) .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 134 --- --- --- --- 1 2 3 5 6 135 7 8 9 10 11 12 13 15 16 Unpaired channels 108 17 18 19 20 21 22 23 24 25 26 109 27 28 29 30 31 32 33 34 35 36 110 37 38 39 40 41 42 43 44 45 46 111 47 48 49 50 51 52 53 54 55 56 112 57 58 59 --- --- --- --- --- --- --- Even-numbered channels paired with ILS localizer Odd-numbered channels paired with VOR 133 --- --- --- 60 61 62 63 64 65 66 134 67 68 69 --- --- --- --- --- --- --- Unpaired channels 112 --- --- --- 70 71 72 73 74 75 76 113 77 78 79 80 81 82 83 84 85 86 114 87 88 89 90 91 92 93 94 95 96 115 97 98 99 100 101 102 103 104 105 106 116 107 108 109 110 111 112 113 114 115 116 117 117 118 119 120 121 122 123 124 125 126 Channels paired with VOR. NOTE:  The unpaired channels (1-16 and 60-69) cannot be received. (3)   Channel  Selection.    After  the  three  VHF NAV frequencies are tuned, DME information from any of   the   three   can   be   displayed   on   the   IND-42A  by sequentially pressing the  CH button to call up T, 2, or 3.      If   one   of   the   three   channels   has   invalid   data, dashes will be displayed. When  DME  data  is  valid,  sequentially  pressing the CH button on the IND-42A will display the  NM and ID for each of the three channels. (4)   Normal Operation. (a)  Select the three desired NAV frequencies   as   previously   described.      Use   the    CH button  on  the  IND-42A  to  select  the  desired  channel for display (1, 2, or 3).  The numeric display will show the   slant   range   distance   from   0   to   300   nm.      The distance  is  accurate  to  0.1  nm  and  the  display  will show  tenths  of  a  mile  from  0  to  199.9  nm,  and  1-mile increments   from   200   to   300   nm.      The   NM   and   ID annunciators will be illuminated and the alphanumeric display    will    show    the    station    identifier.    A    10    to 14 second  memory  in  the  DME-42  prevents  dashes from    being    displayed    if    the    received    –    signal    is temporarily lost or weak. NOTE The   maximum   range   of   the   DME-42   is 300 nm.    The  range  capability  of  a  DME  is limited   by   aircraft   altitude,   obstructions such     as     hills     or     mountains,     and     the curvature of the earth. DME slant range is the straight-line distance   from   the   aircraft   to   the   ground