Hi-VHF Shorted Bowtie Loop with Reflector) analyzed using 4nec2.
Optimum Loop Diameter = 44-in with Half-Inch-Copper-Tubing for 48-in H x 48-in W Screen Reflector (1"x2" Grid). This minimum Screen size was determined by size of typically available fencing material. Angled Reflectors beyond the 48x48 Grid may be added to improve Gain by reducing Horiz. and/or Vert. Azimuthal coverage.
Optimum Diameter for smaller Element sizes may be slightly different.
Hi-VHF Raw Gain = 8.2 to 8.4 dBi, F/B & F/R Ratio = 14.4 to 13.0 dB and SWR (300-ohms) Under 2.5.
Date(s): 18 Sept 2009. Album by holl_ands. 1 - 9 of 9 Total. 7767 Visits.
enlarge 0KB, 902x1024 1 VHF Shorted Bowtie Loop with 48-in H x 48-in W Screen Reflector (1x2) at 20-in Separation 3D View
enlarge 0KB, 1024x983 2 VHF Shorted Bowtie Loop (with Screen Reflector) Front View [One small box = 1.0 inch] Loop Diameter = 44-in with Half-Inch-Copper-Tubing
enlarge 0KB, 550x1024 3 VHF Shorted Bowtie Loop (with Screen Reflector) Side View [One small box = 1.0 inch]
enlarge 0KB, 1024x332 4 VHF Shorted Bowtie Loop (with Screen Reflector) Raw Gain = 8.3+ dBi for Ch7-13 with less in FM Band Raw Gain rapidly falls for Ch2-6 & very poor SWR.
enlarge 0KB, 1024x658 5 VHF Shorted Bowtie Loop (with Screen Reflector) SWR(300-ohm) is 2.0-2.5 for Ch7-13. SWR is EXCESSIVE on Ch2-6.
