Ch13 12-Element Folded Dipole Yagi analyzed using 4nec2. I calculated Dimensions using nikiml's Python Optimization Scripts, with two sets of assumptions. Optimized Dimensions are found in each 4nec2 File and may be rounded to nearest 1/8 or 1/4-inch. Python Optimization Control Script is appended to the end of each 4nec2 File.
Note that, as expected, allowing Boom Length to grow increases Max Gain, whereas constraining element-to-element spacing (Delta) would shrink both Max Gain and Boom Length:
a) Ch12 12-El FD-Yagi with 18-in max spacing between Directors. Target function: (max_ml+64*max_gain_diff+4*max_f2r_diff+max_f2b_diff) Boom Length = 165 inches.
NOTE: Unusually large multiplier tries to find highest Gain rather than best MismatchLoss, F/R or F/B Ratio. Higher value in next Yagi STILL wasn't very effective in suppressing MismatchLoss (SWR), F/R & F/R.
Ch12 Raw Gain Max = 14.85 dBi F/B & F/R Ratio Min = 34 dB on Ch12 SWR (300-ohms) Max = 1.4
b) Ch12 12-El FD-Yagi with 22-in max spacing between Directors. Target function: (max_ml+128*max_gain_diff+4*max_f2r_diff+max_f2b_diff) Boom Length = 192 inches.
BTW: Without targets for f2r & f2b, they reduced to 14 dB, with only 0.1 dB Max Gain increase.
Ch12 Raw Gain Max = 15.65 dBi F/B & F/R Ratio Min = 30 dB on Ch12 SWR (300-ohms) Max = 1.4
Date(s): 15 Mar 2013. Album by holl_ands. 1 - 24 of 24 Total. 5482 Visits.
