22.UHF H2 2-Bay Bowties + Screen ReflectorUHF 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).
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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.
