yes, it is possible to change antennas,  the  Antennas supplied are specially  designed for Delta X as the device  works in the near field and  the Delta X was developed to look for spy devices in  the near field. "More powerful" antennas will Change the concept of Delta X as a portable device with accurate pinpoint of transmitters as well the supplied antennas create a good balance between each  other "more powerful" antennas can increase sensitivity for narrow range but decrease for other ranges..