my boat anchor has different modes; LSB, USB, AM, FM, FSK, and CW mode. i must select a mode before i transmit. i push a button to get into each mode. my 767gx does not allow code to be sent (with a straight key) on any mode other than CW, unless i'm using a computer interface. but, when just listening in to other people transmitting, i've noticed that i can receive transmissions from some people on all modes, meaning, when these people transmit, i can receive them on all modes, some modes are clearer than others but i can hear them on all modes. how is this possible?