Yes. Because the VHF-22D is an extended range VHF comm radio, the CTL-22C control must be strapped to either allow or not allow operation above 135.975 MHz. That is, if it is desired that the VHF-22D only function in the VHF-22C frequency range, then the CTL-22C connection for ext. range (P1 little m to be exact) should not be grounded. Likewise, P1 m connection should be grounded when operation above 135.975 is desired.