A rotary control knob (110) for a portable radio (100) utilizes a flexible shaft (112) as a tether to provide a plurality of flexible positions. The flexible shaft (112) is coupled to a switch mechanism (116) located in the radio housing (102). The rotary control knob (110) can be slid up and down the flexible shaft (112) and the flexible shaft can be bent to provide improved user access to the knob, such as for gloved usage.