UHF H2 2-Bay Bowtie with Screen Grid Reflector Analyzed using 4nec2 after determining OPTIMUM Dimensions using nikiml's Python Optimization Scrips. Performance is significantly better than ANY other 2-Bay Bowtie.
Two versions are Optimized and Analyzed....the second clearly outperforming the first:
a) H2 (9.5"x12") 2-Bay Bowtie with 24"Hx24"W Screen Reflector (Grid=2"Hx4"W), with Hi-VHF Gain to REAR on lower Channels:
UHF Raw Gain = 10.3 to 13.6 dBi, F/B & F/R Ratio Min. = 15.4 dB and SWR (300-ohms) under 2.3. Hi-VHF Raw Gain = -2 to 8 dBi FORWARD and to REAR Raw Gain = 6.9 to 7.3 to 2.5 dBi with Hi-VHF F/B & F/R = 10 to -5 dB and SWR (300-ohms) = 125 to 60.8.
Dimensions (inches): BowLen = 9.5 = Bowtie Whisker Half-Length, ZBowII = 12.0 = Distance between the Centers of the two Bowties, TineSep = 8.25 = Bowtie Tine Separation, BowSwp=0.0 = Bowtie Forward Sweep, FedSep = 1.75 = Separation (in inches) between two FEEDLINE wires, RS = -4.75 = Separation between Bowties and Reflector. Screen Reflector = 24-in H x 24-in W, 2"Hx4"W Grid (1"Hx2"W would improve F/B & F/R Ratios).
====================================== b) H2 (10"x15") 2-Bay Bowtie with 36"Hx36"W Screen Reflector (Grid=1"Hx2"W), with significantly higher UHF Gain and more Hi-VHF Gain aligned FORWARD:
UHF Raw Gain = 12.9 to 14.5 dBi, F/B & F/R Ratio Min = 22.5 dB and SWR (300-ohms) Under 2.8. Hi-VHF Raw Gain = 8.2 to 8.6 dBi, F/B & F/R Ratio = 9.8 to 15.9 dB and SWR (300-ohms) = 93 to 31 is Excessive.
Dimensions: (inches) BowLen = 10.0 = Bowtie Whisker Half-Length, ZBowII = 15.0 = Distance between the Centers of the two Bowties, TineSep = 10.0 = Bowtie Tine Separation, BowSwp=0.0 = Bowtie Forward Sweep, FedSep = 2.75 = Separation (in inches) between two FEEDLINE wires, RS = -5.0 = Separation between Bowties and Reflector. Screen Reflector = 36-in H x 36-in W, 1"Hx2"W Grid.
Date(s): 9 Feb 2015. Album by holl_ands. 1 - 42 of 42 Total. 17669 Visits.
enlarge 148KB, 761x1024 1 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W 3D View
enlarge 330KB, 1015x1024 2 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Front View [1 large square = 2.5 inches]
enlarge 136KB, 506x1024 3 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Top View [1 large square = 2.5 inches]
enlarge 182KB, 1024x741 4 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W UHF Raw Gain = 10.3 to 13.6 dBi UHF F/B & F/R Ratio Minimum = 15.4 dB
enlarge 185KB, 1024x741 5 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W UHF SWR (300-ohms) Under 2.3
enlarge 136KB, 499x1024 15 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Side View [1 large square = 2.5 inches]
enlarge 113KB, 1152x497 16 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Hi-VHF Raw Gain = -2 to 8 dBi FORWARD
enlarge 169KB, 1024x741 17 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Hi-VHF Raw Gain = 6.9 to 7.3 to 2.5 dBi MORE TO REAR on Lower Channels Hi-VHF F/B & F/R 10 to -5 dB
enlarge 192KB, 1024x741 18 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Hi-VHF SWR (300-ohms) = 125 to 60.8
enlarge 305KB, 1024x1024 19 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Azimuthal Pattern at 174 MHz More Gain to REAR on Lower Channels
enlarge 313KB, 1024x1024 20 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Azimuthal Pattern at 198 MHz Bi-Directional Mid-Band
enlarge 308KB, 1024x1024 21 UHF H2-Bay (9.5"Hx12"W) Bowtie plus Screen Reflector (24"Hx24"W), Grid=2"Hx4"W Azimuthal Pattern at 216 MHz More Gain FORWARD on Higher Channels
enlarge 244KB, 1007x1024 22 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W 3D View
enlarge 399KB, 1024x886 23 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W Front View [1 large square = 2.5 inches]
enlarge 137KB, 448x1024 24 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W Top View [1 large square = 2.5 inches]
enlarge 178KB, 1024x722 25 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W UHF Raw Gain = 12.9 to 14.5 dBi UHF F/B & F/R Ratio Min = 22.5 dB
enlarge 184KB, 1024x722 26 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W UHF SWR (300-ohms) Under 2.8
enlarge 168KB, 1024x722 34 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W Hi-VHF Raw Gain = 8.2 to 8.6 dBi Hi-VHF F/B & F/R Ratio = 9.8 to 15.9 dB
enlarge 190KB, 1024x722 35 UHF H2-Bay (10"Hx15"W) Bowtie plus Screen Reflector (36"Hx36"W), Grid=1"Hx2"W Hi-VHF SWR (300-ohms) = 93 to 31 is Excessive
