UHF Chireix Zig-Zag Antennas (with Reflectors) analyzed using 4nec2.
In RevA, Zig-Zag Wire Lengths in top-left quadrant were slightly different than other quadrants. NO significant performance differences were found after making them all the SAME (RevB, also RevX), see Chart at bottom.
RevC (C-Cups), RevX (Top-Hats) and RevR (Roof) added NARODS to improve Hi-VHF performance, although at expense of UHF.
RevA, B, C, X and R employ STAGGER TUNING, wherein the Wire Lengths for "Zigs" connected to the center SOURCE wire are longer than the "Zags" returning back towards the Z-axis.
RevD and RevH are standard 2-Square Chireix Antennas wherein all Wire Lengths are the SAME, at 45-degree angles. RevD provided more Gain at higher frequencies, using the same 12 Reflector Rods as Rev A/B. RevH (Big Screen Reflector) provided much higher F/R and F/B Ratios and good Gain across the New UHF Band. Screen size is same as RevA/B Reflector Rod footprint....and may be larger than needed.
2-Square Chireix and X340 variants have LESS Gain than the CM4221 4-Bay, and NONE are suited for use on Ch52-69 (like the CM4221). 4-Square Chireix has more Gain than CM4221 mid-band, but drops off at very low and very high frequencies with lower F/R and F/B Ratios.
Hi-VHF Performance to be provided in the near future....
EDIT (28Apr2011): Corrected Dimensions in 4-Square Chireix - Front View. Corrected comment: [One small box = 1 inch] 60'H x 32"W Reflector Results and 4nec2 file are unaffected. Added Raw Gain, SWR, Impedance and Azimuthal Pattern Charts for 4-Square Chireix with Reflector Screen.
Date(s): 30Aug2009. Album by holl_ands. 1 - 37 of 37 Total. 527 Visits.
enlarge 0KB, 1024x696 1 X340 variants vs 2-Square Chireix vs CM4221 Raw and Net Gain Compared
enlarge 0KB, 1024x696 2 X340 variants vs 2-Square Chireix vs CM4221 F/R and F/B Ratios Compared
enlarge 0KB, 1024x696 3 CM4221 outperforms 2-Square Chiereix But 4-Square Chiereix has more mid-band Gain.
enlarge 0KB, 613x1024 4 X340 RevA - 3D View 2-Square Chireix with 12 Reflector Rods. Stagger-Tuning: "Zigs" radiating from SOURCE LARGER than "Zags" headed back towards Z-Axis.
enlarge 0KB, 940x1024 5 X340 RevA - Front View [One small box =0.5 inch]
Notice top-left Zig-Zag doesn't match the others.
enlarge 26KB, 791x1024 6 4nec2 for WildWillie's X340 RevA: 2-Square Chireix with 12 Reflector Rods. Stagger-Tuning: "Zigs" radiating from SOURCE LARGER than "Zags" headed back towards Z-Axis.
enlarge 0KB, 659x1024 7 X340 RevB - 3D View Same as RevA, except odd-ball Wire Lengths in top-left quadrant are now same as other quadrants. All Inner Zigs=10.52-in and all Outer Zags=9.22-in.
enlarge 0KB, 944x1024 8 X340 RevB - Front View [One small box =0.5 inch]
Now all four quadrants are the SAME with NO SIGNIFICANT PERFORMANCE DIFFERENCES.
enlarge 27KB, 791x1024 9 4nec2 for X340 RevB: Same as RevA, except odd-ball Wire Lengths in top-left quadrant are now same as other quadrants. All Inner Zigs=10.52-in and all Outer Zags=9.22-in.
enlarge 0KB, 652x1024 10 2-Square Chireix RevD - 3D View ALL Wire Lengths=9.75-in at 45-degree angles with RevA/B's 12 Reflector Rods.
enlarge 0KB, 926x1024 11 2-Square Chireix RevD - Front View [One small box = 0.5 inch] Notice all Wires are SAME length at 45-deg angles.
enlarge 26KB, 791x1024 12 4nec2 for 2-Square Chireix RevD: ALL Wire Lengths=9.75-in at 45-degree angles with RevA/B's 12 Reflector Rods.
enlarge 0KB, 660x1024 13 2-Square Chireix RevH - 3D View Big 35"H x 26"W Reflector Screen, ALL Wire Lengths=9.25-in.
enlarge 0KB, 921x1024 14 2-Square Chireix RevH - Front View [One small box = 0.5 inch] 35"H x 26"W matches RevA outline.
enlarge 90KB, 791x1024 15 4nec2 for 2-Square Chireix Rev H: Big 35"H x 26"W Reflector Screen, ALL Wire Lengths=9.25-in.
enlarge 0KB, 1022x1024 16 X340 RevC - 3D View Same as RevA except 16 Reflector Rods and 2 C-Cups to improve Hi-VHF.
enlarge 0KB, 1024x941 17 X340 RevC - Front View [One small box =0.5 inch] Inner Cheriex is SAME as RevA.
enlarge 29KB, 791x1024 18 4nec2 for X340 RevC: Same as RevA except 16 Reflector Rods and 2 C-Cups to improve Hi-VHF.
enlarge 0KB, 935x1024 19 X340 RevX - 3D View Xauto's X353 change to RevB uses 2 Top-Hat NARODs with 10 Reflector Rods. All Inner Zigs=10.182-in and all Outer Zags=9.475-in.
enlarge 0KB, 1024x815 20 X340 RevX - Front View [One small box =0.5 inch] Inner Chireix is SAME as RevB.
enlarge 26KB, 791x1024 21 4nec2 for X340 RevX: Xauto's X353 change to RevB uses 2 Top-Hat NARODs with 10 Reflector Rods. All Inner Zigs=10.182-in and all Outer Zags=9.475-in.
enlarge 0KB, 1020x1024 22 X340 RevR - 3D View Xauto's X353 change to RevA uses 2 "Roof" shaped NARODs with 16 Reflector Rods.
enlarge 0KB, 1024x955 23 X340 RevR - Front View [One small box =0.5 inch] Inner Cheriex is SAME as RevA.
enlarge 28KB, 791x1024 24 4nec2 for X340 RevR: Xauto's X353 change to RevA uses 2 "Roof" shaped NARODs with 16 Reflector Rods.
enlarge 0KB, 635x1024 25 4-Square Chireix - 3D View 30"H x 16"W Reflector Screen at 4-in Separation. ALL Wire Lengths = 9.75-in
enlarge 0KB, 738x1024 26 4-Square Chireix - Front View [One small box = 1 inch] Smaller 60'H x 32"W Reflector Screen
enlarge 59KB, 791x1024 27 4-Square Chireix - 4nec2 File 30"H x 16"W Reflector Screen at 4-in Separation
enlarge 161KB, 1152x710 28 4-Square Chireix with Reflector Screen UHF Raw Gain
enlarge 202KB, 1152x710 29 4-Square Chireix with Reflector Screen UHF SWR (300-ohm) under 2.6
