I haven't tried this my self.
It seems logical that you take the loop wire and connect one end to the wire in the middle of the coax and the other end to the wire around the coax (shield). If you use resistor place it in the middle of the loop.
18 gauge speaker wire seems to be the most recommended wire for the loop and 5 watt, 420 ohm, 1% tolerance for the resistors. I don't see any harm in higher tolerance resistor if people are getting good results without the resistor.