The ACB-4 Comtek Hybrid Quadrature Phasing Coupler is 47 ½ feet from each vertical.  Coax with solid polyethylene has a velocity factor of .69 and the ¼ wave length is 46 ¼ feet long.  Therefore, polyfoam coax must be used, since, with the higher velocity factor, the length is sufficient to make the distance.  The design requires a ¼ wave section of 75 ohm coax.  RG-59 (TV Foam Coax) is not rated for 400 watts, but RG-6 foam can handle the power level. 

RG-6 coax with a copper braid is available, but the specifications state the velocity factor is .81 or .83.  It is very important to actually measure a known length (open circuit) and measure the actual resonance (where the impedance is maximum), and work backwards to determine the actual velocity factor.  With my measurement, the velocity factor came out to be .78, and each length was cut to 52 feet 9 inches. 

At the end which will be connected to the ACB-4 Comtek Hybrid Quadrature Phasing Coupler, label tags are provided by Comtek.  Place these labels on each coaxial cable, and securely attach the opposite end to the bulkhead connector at each antenna base.  I used 1 as the NW antenna, 2 as the NE antenna, 3 as the SE antenna and 4 as the SW antenna.  Run each cable tie wrapped to the # 6 AWG copper ground rod that crosses near the ACB-4 Comtek Hybrid Quadrature Phasing Coupler.