A catheter, comprising: an elongated catheter body comprising a first tubular structure having first central lumen, a distal end and a proximal end; a deflectable section having a second tubular structure having a second central lumen, and a proximal end that is distal of the proximal end of the catheter body; a flat beam having first and second opposing surfaces, the flat beam extending through at least the deflectable section generally axially bisecting the second central lumen into a first lumen half and a second lumen half, the flat beam having a neutral bending axis and adapted to deflect in two opposing directions from the neutral bending axis, the flat beam having a distal end at or near the distal end of the second tubular structure, and a proximal end extending into the distal end of the first tubular structure; a puller wire configured with first and second long segments (28A,28B) and a U-bend segment therebetween, the U-bend section anchored to the distal end of the flat beam, the first long segment extending through the first lumen half of the deflectable section and through the first central lumen of the catheter body, the second long segment extending through the second lumen half of the deflectable section and through the first central lumen of the catheter body; a compression coil having a proximal end at or near the proximal end of the catheter body and a distal end defining a first deflection initiation location along the deflectable section, the compression coil extending through the first central lumen of the catheter body and through only the first lumen half of the deflection section, the compression coil having a coil lumen, the compression coil surrounding a portion of the first long segment of the puller wire extending through the coil lumen, a stop having a bore configured to receive a distal end of the compression coil with the first long segment of the puller wire therein extending through the bore, the stop configured to affix the compression coil to the first surface of the flat beam; at least one spacer extending axially on at least one surface of the beam configured to provide a predetermined separation distance between the respective puller wire long (28A,28B) segment and the at least one surface of the beam. an elongated catheter body comprising a first tubular structure having first central lumen, a distal end and a proximal end; a deflectable section having a second tubular structure having a second central lumen, and a proximal end that is distal of the proximal end of the catheter body; a flat beam having first and second opposing surfaces, the flat beam extending through at least the deflectable section generally axially bisecting the second central lumen into a first lumen half and a second lumen half, the flat beam having a neutral bending axis and adapted to deflect in two opposing directions from the neutral bending axis, the flat beam having a distal end at or near the distal end of the second tubular structure, and a proximal end extending into the distal end of the first tubular structure; a puller wire configured with first and second long segments (28A,28B) and a U-bend segment therebetween, the U-bend section anchored to the distal end of the flat beam, the first long segment extending through the first lumen half of the deflectable section and through the first central lumen of the catheter body, the second long segment extending through the second lumen half of the deflectable section and through the first central lumen of the catheter body; a compression coil having a proximal end at or near the proximal end of the catheter body and a distal end defining a first deflection initiation location along the deflectable section, the compression coil extending through the first central lumen of the catheter body and through only the first lumen half of the deflection section, the compression coil having a coil lumen, the compression coil surrounding a portion of the first long segment of the puller wire extending through the coil lumen, a stop having a bore configured to receive a distal end of the compression coil with the first long segment of the puller wire therein extending through the bore, the stop configured to affix the compression coil to the first surface of the flat beam; at least one spacer extending axially on at least one surface of the beam configured to provide a predetermined separation distance between the respective puller wire long (28A,28B) segment and the at least one surface of the beam.