is located on the forward side of the support when the fish strikes line 120 the forward segment of the swinging arm swings down while the rear segment 122 swings up when the rear segment has swung up from a lower position in which the magnetic field of magnet 102 is powerful enough to open the reed switch to an upper position in which the magnetic field is too week to continue to hold the switch open and the switch closes and a signal is generated in fig7 the reed switch is closer to magnet 102 than it is in fig8 the arc of upward travel of the rear segment 122 of the swinging arm while the magnet affects the operation of the reed switch is accordingly greater in fig7 than it is in fig8 in fig7 the arc is set at 20 degrees while in fig8 support 114 has been rotated 180 degrees as indicated by arrow a so that the reed switch is on the opposite side of the support and the arc of travel is set at 5 degrees these numbers are arbitrary and can be adjusted in a number of ways one way is to substitute a magnet of increased or decreased strength for magnet 102 another way is to slide the swinging arm along the fulcrum fo alter the spacing between magnet 102 and the reed switch a still further way to alter the arc or angle of travel of the swinging arm is.