At some point in 1958 or 1959, in the very early days of CB Radio Gonset, 
for whatever reason thought it would be a good idea to have their 
own channel numbers. These are often seen rubber stamped  on very 
early model Gonset units such as the Gonset Citizens' Communicator G-11.

My Gonset G-11 is stamped Channel 8 FREQ. MC 27.085. This would be 
where Channel 11 is located when using conventional channel numbers.

The idea behind this channel scheme  was to use the two digits to the 
right of the decimal to indicate the channel number. I had not found 
any explanation to these odd channel numbers till I found it in the
October 1959 issue of CQ Magazine. 

     

  CB CHANNEL        GONSET CHANNEL       FREQUENCY
     
      1                   96              26.965
      2                   97              26.975
      3                   98              26.985
      4                   100             27.005
      5                   1               27.015
      6                   2               27.025
      7                   3               27.035
      8                   5               27.055
      9                   6               27.065
      10                  7               27.075
      11                  8               27.085
      12                  10              27.105
      13                  11              27.115
      14                  12              27.125
      15                  13              27.135
      16                  15              27.155
      17                  16              27.165
      18                  17              27.175
      19                  18              27.185
      20                  20              27.205
      21                  21              27.215
      22                  22              27.225
      23                  25              27.255



I can imagine the amount of confusion that this caused for users of other radios
that had used channel numbers without specifying the frequency. 
Channels 20, 21, 22 fall in line with the normal channel numbers.