A method of manufacturing a flexible catheter with a locatable sensor , the method comprising: (a) non-rotatably coupling a first spool to a first portion of a spool carrier , a first portion of a single monolithic wire being wrapped about the first spool and a second portion of the wire being wrapped about a second spool ; non-rotatably coupling the spool carrier to a catheter body ; routing the wire through a wire guide and positioning the wire across an outer surface of the catheter body prior to rotating the spool carrier; rotating the spool carrier with the catheter body, thereby wrapping the second portion of the wire about a distal end portion of the catheter body to form a first wrapping layer of the sensor at the distal end of the catheter; (b) coupling the first spool and the second spool to a drive motor ; and simultaneously: activating the drive motor to rotate the first and second spools about a common axis, whereby first and second leads corresponding to each free end of the wire of the first wrapping layer twist together to form a twisted pair of the wire; and rotating the catheter body about a longitudinal axis defined by the catheter body, whereby the twisted pair of the wire wraps about a proximal end portion of the catheter body. (a) non-rotatably coupling a first spool to a first portion of a spool carrier , a first portion of a single monolithic wire being wrapped about the first spool and a second portion of the wire being wrapped about a second spool ; non-rotatably coupling the spool carrier to a catheter body ; routing the wire through a wire guide and positioning the wire across an outer surface of the catheter body prior to rotating the spool carrier; rotating the spool carrier with the catheter body, thereby wrapping the second portion of the wire about a distal end portion of the catheter body to form a first wrapping layer of the sensor at the distal end of the catheter; non-rotatably coupling the spool carrier to a catheter body ; routing the wire through a wire guide and positioning the wire across an outer surface of the catheter body prior to rotating the spool carrier; rotating the spool carrier with the catheter body, thereby wrapping the second portion of the wire about a distal end portion of the catheter body to form a first wrapping layer of the sensor at the distal end of the catheter; (b) coupling the first spool and the second spool to a drive motor ; and simultaneously: activating the drive motor to rotate the first and second spools about a common axis, whereby first and second leads corresponding to each free end of the wire of the first wrapping layer twist together to form a twisted pair of the wire; and rotating the catheter body about a longitudinal axis defined by the catheter body, whereby the twisted pair of the wire wraps about a proximal end portion of the catheter body. activating the drive motor to rotate the first and second spools about a common axis, whereby first and second leads corresponding to each free end of the wire of the first wrapping layer twist together to form a twisted pair of the wire; and rotating the catheter body about a longitudinal axis defined by the catheter body, whereby the twisted pair of the wire wraps about a proximal end portion of the catheter body. <EOS>