UHF 4-Square Free Form Chireix

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UHF 4-Square Free Form Chireix

4-Square Chireix, Free Form (Unequal Inner/Outer Lengths & Angles) Antenna with
NO Reflector and also 11 Reflector Rods analyzed using 4nec2.

There are FIVE Gaps: Center Feedpoint, Outer Apexes and In-Between. See respective
Front Views & 4nec2 Files. Dimensions from nikiml's Python Optimization Scripts.

Both versions had 4-5 dB Loss on lowest channels and No Reflector had 2.6 dB Loss on
highest Channels, so Stagger-Tuning alone was insufficient for Full UHF Band coverage.
Four-Unequal-Diamonds with 11 Reflector Rods had MUCH better performance:
http://imageevent.com/holl_ands/multidiamond/uhf4unequaldiamonds11reflrods

a) UHF 4-Square Free Form Chireix - NO Reflector:
UHF Raw Gain = 5.7 to 10.0 to 7.4 dBi and SWR (300-ohms) under 1.9.

b) UHF 4-Square Free Form Chireix + 11RR:
UHF Raw Gain = 8.5 to 14.3 to 14.2 dBi,
F/B & F/R Ratio Minimum = 15.1 dB and SWR (300-ohms) under 12.5.

Date(s): 15 Oct 2014. Album by holl_ands. 1 - 27 of 27 Total. 17602 Visits.

enlarge 65KB, 661x1024 1 UHF 4-Square Free Form Chireix - NO Refl 3D View	enlarge 143KB, 487x1024 2 UHF 4-Square Free Form Chireix - NO Refl Front View [1 large square = 5 inches] Gap at Outer Apexes = 0.5-inches Other Gaps = 0.75-inches	enlarge 28KB, 791x1024 3 UHF 4-Square Free Form Chireix - NO Refl 4nec2 File
enlarge 151KB, 1024x690 4 UHF 4-Square Free Form Chireix - NO Refl UHF Raw Gain = 5.7 to 10.0 to 7.4 dBi	enlarge 192KB, 1024x690 5 UHF 4-Square Free Form Chireix - NO Refl UHF SWR (300-ohms) Under 1.9	enlarge 223KB, 1024x690 6 UHF 4-Square Free Form Chireix - NO Refl UHF Impedance
enlarge 311KB, 1024x1024 7 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 470 MHz	enlarge 313KB, 1024x1024 8 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 530 MHz	enlarge 317KB, 1024x1024 9 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 590 MHz
enlarge 315KB, 1024x1024 10 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 650 MHz	enlarge 313KB, 1024x1024 11 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 698 MHz	enlarge 287KB, 1024x1024 12 UHF 4-Square Free Form Chireix - No Refl Azimuthal Pattern at 806 MHz
enlarge 103KB, 692x1024 13 UHF 4-Square Free Form Chireix + 11RR 3D View	enlarge 209KB, 744x1024 14 UHF 4-Square Free Form Chireix + 11RR Front View [1 large square = 5 inches] Center Feedpoint Gap = 0.75-inches Other Gaps = 0.5-inches	enlarge 110KB, 412x1024 15 UHF 4-Square Free Form Chireix + 11RR Top View [1 large square = 2.5 inches]
enlarge 169KB, 1024x690 16 UHF 4-Square Free Form Chireix + 11RR UHF Raw Gain = 8.5 to 14.3 to 14.2 dBi UHF F/B & F/R Ratio Minimum = 15.1 dB	enlarge 188KB, 1024x690 17 UHF 4-Square Free Form Chireix + 11RR UHF SWR (300-ohms) Under 2.5	enlarge 215KB, 1024x690 18 UHF 4-Square Free Form Chireix + 11RR UHF Impedance
enlarge 297KB, 1024x1024 19 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 470 MHz	enlarge 298KB, 1024x1024 20 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 530 MHz	enlarge 301KB, 1024x1024 21 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 590 MHz
enlarge 301KB, 1024x1024 22 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 650 MHz	enlarge 301KB, 1024x1024 23 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 698 MHz	enlarge 300KB, 1024x1024 24 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 758 MHz
enlarge 301KB, 1024x1024 25 UHF 4-Square Free Form Chireix + 11RR Azimuthal Pattern at 806 MHz	enlarge 30KB, 791x1024 26 UHF 4-Square Free Form Chireix + 11RR 4nec2 File	enlarge 97KB, 371x1024 27 UHF 4-Square Free Form Chireix + 11RR Side View [1 large square = 5 inches]

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Hi
thanks for the info here, it gives me something to start with

Andrew
- Andrew, Sat, 17 Jul 2021 7:19AM