Convert a Frequency to a Channel:
   o Take the hundredths number in the frequency [i.e. in 72.630, use 63]
   o Subtract 21 from this number [63 - 21 = 42]
   o Divide by 2 [42 / 2 = 21]
   o Add 21 to the result [21 + 21 = 42]
   o The result is the channel number: 42

	 Convert a Channel to a Frequency:
   o Subtract 21 from the channel number (channel 28) [28 - 21 = 7]
   o Multiply the number by 2 [7 * 2 = 14]
   o Add 21 to this number [14 + 21 = 35]
   o Result can be found by prepending "72" in front of this number [72.350]
   o The result: frequency is 72.350MHz for channel number 28