There's a lot of information available about how to block common mode current originating at the antenna end of a coax cable. But, I haven't seen any reference to common mode current originating at the transmitter. If common mode current is on the outside of the cable's shield (as many people describe it), and both the inside and outside of the cable braid are connected to the same wire in the radio (which they are), and the feed line is the right length to be an effective radiator (which could happen), wouldn't the shielding be radiating like crazy? That doesn't seem to happen in real life, so I feel like I'm missing a crucial piece of information here. What's stopping common mode current from originating at the transmitter?