Wasn't there also an esoteric way of working out the right DME freq to get the range from a TACAN. I think you add 53 to the low channels and 63 to the higher ones to get the last 3 digits of the freq to dial up. Eg, for channel 70, add 53 to get 123 and thus dial up 112.3 to get the range.
Unless you know better...........
Cheers,
mcdhu