I did not try it (nor do I have measurement tools to measure effects reliably), but @Normis wrote a topic post about setting Tx power: http://forum.mikrotik.com/t/antenna-gain-missing-in-6-46-8/145162/1 … I’ve no reason not to believe in what a MT staffer writes and according to what he wrote, things are plain simple. The only problem remaining is the name of parameter.