Horizontally Stacked UHF Hourglass-Loops (NO Reflectors) analyzed using 4nec2. All dimensions were determined using nikiml's Python Optimization Scripts.
An UHF Hourglass-Loop has a VERY WIDE Beamwidth of 80-deg at 470 MHz, decreasing to 70-deg at 698 MHz. Horizontally Stacked, it drops to 40-deg at 470 MHz, and 30-deg at 698 MHz (to within 10-deg resolution).
Two versions are presented here, the first presumes the use of an RF Combiner attached to Antenna Feedpoints using Baluns & Equal Length Cables. The second avoids 0.5-1.5+ dB Loss in RF Combiner by using an Optimized Horizontal Interconnection Harness.
a) RF Combiner: Horizontal Stacking (Center-Center), HD = 16-in provides Max Raw Gain per Optimizer.
UHF Raw Gain = 7.8 to 9.8 to 9.5 dBi and (300-ohms) under 1.9.
===================================== b) Holl_ands Horizontal Harness (HHH): Interconnection using HHH rather than RF Combiner, otherwise ALL Dimensions are the SAME as the above Model.
Dimensions of HHH wires were determined using nikiml's Python Optimization Scripts: HD = 16.0-in = Horizontal Stacking Distance (Center-To-Center). HD/2 = 8.0-in, Length of Harness wires from Feedpoint to Center of each Hourglass-Loop was per above Model: Diagonal = 4.0-in, Length from Harness Wires to each Hourglass-Loop Feedpoint. Hw = 1.43-in (may round to 1.5-in), Xh = -3.75-in = X-Axis Separation between Harness Wires and Hourglass-Loops. TOTAL HARNESS WIRE LENGTH (2 required) = 25-in = 2x8.0+2x4.0+2x0.5 (for eyelet)
UHF Raw Gain = 8.6 to 10.1 dBi, F/B and F/R Ratio = 3.5 to 1.8 dB and (300-ohms) under 1.9.
Note that HHH acts somewhat as a REFLECTOR, increasing Raw Gain in the Forward direction, providing significantly MORE Gain than RF Combiner Model above....and NO LOSS due to Combiner.
Date(s): 14 Jun 2014. Album by holl_ands. 1 - 33 of 33 Total. 1913 Visits.
enlarge 91KB, 974x1024 1 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax 3D View
enlarge 215KB, 1152x663 2 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Front View HD = 18-in = Horiz. Stack Distance (Ctr-Ctr) [1 large square = 2.5-inches]
enlarge 75KB, 272x1024 3 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Top View [1 large square = 2.5-inches]
enlarge 154KB, 1024x675 4 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax UHF Raw Gain = 7.8 to 9.8 to 9.5 dBi
enlarge 84KB, 403x1024 15 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Side View [1 large square = 2.5-inches]
enlarge 166KB, 1024x675 16 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Sensitivity Analysis at 470 MHz Raw Gain vs HS (Separation between Hourglasses]
enlarge 164KB, 1024x675 17 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Sensitivity Analysis at 584 MHz Raw Gain vs HS (Separation between Hourglasses]
enlarge 162KB, 1024x675 18 Horiz-Stack UHF Hourglass-Loop - NO Refl RF Combiner, Baluns & Equal-Length Coax Sensitivity Analysis at 698 MHz Raw Gain vs HS (Separation between Hourglasses]
enlarge 94KB, 808x1024 19 Horiz-Stack UHF Hourglass-Loop - NO Refl Holl_ands Horizontal Harness 3D View
enlarge 224KB, 1152x670 20 Horiz-Stack UHF Hourglass-Loop - NO Refl Holl_ands Horizontal Harness Front View HD = 18-in = Horiz. Stack Distance (Ctr-Ctr) [1 large square = 2.5-inches]
enlarge 104KB, 349x1024 21 Horiz-Stack UHF Hourglass-Loop - NO Refl Holl_ands Horizontal Harness Top View HD = 18-in = Horiz. Stack Distance (Ctr-Ctr) [1 large square = 2.5-inches]
enlarge 165KB, 1024x675 22 Horiz-Stack UHF Hourglass-Loop - NO Refl Holl_ands Horizontal Harness UHF Raw Gain = 8.6 to 10.1 dBi UHF F/B & F/R Ratio = 3.5 to 1.8 dB
enlarge 187KB, 1024x675 23 Horiz-Stack UHF Hourglass-Loop - NO Refl Holl_ands Horizontal Harness UHF SWR (300-ohms) Under 2.7
