This is a conventional method of feeding 6 Yagis using a 4 way power distributor
which has been used in the 4 Yagi array. (FIG.2)
To feed the same power to each array, you need to provide 2/3 power to the old four Yagi feeding system and 1/3 to two Yagis newly added under the same phase conditions.
This is accomplished by using a Power distributor of ratio 2:1 as in FIG.1. See NOTE 1 and NOTE 2. A new power distributor is made with half wave coaxial line with a characteristic impedance of 61.23 ohm.
where WI = SQR(25*150) = 61.23 ohm W2 = SQR(50* 75) = 61.23 ohm Coaxial D/d of 61.23 ohm is around 2.77, for adequate pipe selection, 25mm/9mm = 2.78, 22/8 = 2.75, 14/5 = 2.80, 11/4 = 2.75 NOTE 1: Power distribution ratio PI = E*E/Rl= E*E/150 P2 = E*E/R2= B*E/75 = 2*Pl NOTE 2: Impedance matching Z = RI*R2/(Rl+R2) = 150*75/(150+75) =50Another important point is to be in-phase at each antenna. As every power distriburtor is a quarter wave Impedance transformer, in-phase condition is accomplished by the following two cases of line length in FIG.2.
CASE I L2 = 0.25 wavelength and L3 = LI CASE 2 L2 = 0.5 wavelength and L3 = LI - 0.25 wavelength