UHF Chireix Zig-Zag Antennas (NO Reflectors) analyzed using 4nec2. Henri Chireix's Canadian Patent CA285256A is dated 12 Apr 1928: http://brevets-patents.ic.gc.ca/opic-cipo/cpd/eng/patent/285256/summary.html http://lost-contact.mit.edu/afs/club.cc.cmu.edu/usr/sdavis/pdfs/chireix-mesny.pdf
2-Square Whisker Length = WL = 10.0-in (at 45-deg) assumed in this Analysis. To reduce excessive SWR in 2-Square WL=10.5-in is advised. 4-Square WL=10.25-in [SWR under 2.6] and for 6-Square and 8-Square WL=10.5-in is assumed [SWR under 2.6]. All AWG12. As more "squares" are added to the Chireix, the Gain is increased with increasingly reduced Bandwidth.
Although a square box (45-deg to horizontal plane) is typically used, a slightly higher Gain was found in a 4-Square Chireix at 40-deg.
A Free-Form 4-Diamond Chireix can be found here, with "BEST" Angles and Lengths: https://imageevent.com/holl_ands/chireix/uhf4squarechireixfreeform
EDIT (2Mar2018): Added 4nec2 Files and Dimension Info.
Date(s): 17 Aug2009. Album by holl_ands. 1 - 27 of 27 Total. 21281 Visits.
enlarge 0KB, 592x1024 1 2-Square Chireix Zig-Zag Antenna [1 large square = 2.5 inches] Zig-Zag Lengths = 10.0-inches Feedpoint Gap = 0.75-inches Gap at All Other Apexes = 0.75-inches
enlarge 0KB, 1024x819 2 2-Square Chireix Zig-Zag Antenna UHF Raw Gain = 7.4 to 9.6 dBi
enlarge 0KB, 1024x819 3 2-Square Chireix Antenna SWR (300-ohm) Under 3.3 is a bit High
enlarge 0KB, 1024x819 4 2-Square Chireix Antenna - SWR (200-ohm) Slightly better SWR at Hi & Lo Freqs
enlarge 0KB, 391x1024 7 4-Square Chireix Zig-Zag Antenna [1 large square = 5 inches] Zig-Zag Lengths = 10.25-inches Feedpoint Gap = 0.75-inches Gap at All Other Apexes = 0.75-inches
enlarge 0KB, 1024x819 8 4-Square Chireix Zig-Zag Antenna UHF Raw Gain Max = 12.2 dBi with Low Gain on Low Channels
enlarge 0KB, 423x1024 13 6-Square Chireix Zig-Zag Antenna [1 large square = 12.5 inches] Zig-Zag Lengths = 10.5-inches Feedpoint Gap = 0.75-inches Gap at All Other Apexes = 0.75-inches
enlarge 0KB, 1024x819 14 6-Square Chireix Zig-Zag Antenna UHF Raw Gain Max = 13.6 dBi with Low Gain on Low & High Channels
enlarge 0KB, 292x1024 17 8-Square Chireix Zig-Zag Antenna Zig-Zag Lengths = 10.5-inches Feedpoint Gap = 0.75-inches Gap at All Other Apexes = 0.75-inches
enlarge 0KB, 1024x819 18 8-Square Chireix Zig-Zag Antenna UHF Raw Gain Max = 14.4 dBi with Low Gain on Low & High Channels
