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holl_ands | Home > Omni & Quasi-Omni Directional Antennas > Browse:FM Flat-Swept SBGH H-POL OMNI-PLUSFM TRIAD 4xRectangular-Loops H-OMNI-PLUSFM Goalkeeper Quad-Trap+Spurs Quasi-OMNIFM TRIAD Array of Dipoles H-OMNIFM Double-Hoop H-POL OMNIFM Double-Hoop + Vertical-Dipole OutsideFM Double-Hoop + Vertical-FD-OutsideFM Double-Hoop + Vert. Dipole In CenterFM Double-Hoop + Vertical-FD-In-CenterFM Double-Hoop + Vertical Whip OutsideFM Vertical Folded Dipole VPOL TRUE-OMNIFM Vertical Stick Dipole V-POL TRUE-OMNIFM + VHF Discone V-POL TRUE-OMNIFM Monopole Whip over Groundplane OMNIFM Turnstile QuasiOMNI Antennacraft FMSSFM Turnstile Quasi-Omni - AlternateFM Turnstile - A-C FMSS RotatedFM ESS Curves - Fracarro & DipolFM ZigZag - Triax FM ZigmaFM Right Circular Folded Dipole PairFM Cycloid Dipole - Circular Polarized490 MHz Flat-Swept SBGH H-POL OMNI-PLUS490 MHz Flat-Swept SBGH OMNI + TOP-HAT490 MHz 3-Dipole TRIAD Array H-POL OMNI490 MHz Crossed-Dipoles + One TL - OMNI490 MHz Crossed-Dipoles, 2 Unequal TLs490 MHz 7-El Yagi TRIAD H-POL OMNI-PLUS490 MHz 4El Yagi Triad H-POL True-OMNI490 MHz Collinear Helical HPOL OMNI-PLUS490 MHz Double Diamond H-POL Quasi-OMNIUHF Vertical Folded Dipole V-POL OMNIUHF SBGH H-POL OMNI-PLUS by nikimlUHF Hoverman Type 1 H-POL Quasi-OmniUHF M4 (10x9.5) Twisted 4-Bay Quasi-OMNIUHF 2xM4 Twisted 8-Bay - Quasi-OMNIHi-VHF Goalkeeper Quad-Trapezoid+SpursHi-VHF Monopole Whip V-POL TRUE-OMNIHi-VHF Vertical Folded Dipole OMNICh2-69 Crossed Loops 90-deg Phase ShiftCh2-69 + FM Crossed Loops - UVOX-22m "Classic" 3QWL+QWL J-Pole
FM Turnstile Quasi-Omni - Alternate FM Turnstile (two Folded Dipoles at 90-degrees to each other) analyzed using 4nec2. Separation between Folded Dipole Elements = 3-in, overall Height = 14-in. Folded Dipole lengths were tweaked to minimize SWR, resulting in two different lengths: 51.5-in for 75-ohms and 62-in for 300-ohms, presuming 3-in FD Element Separation.  Both are shown below. Antenna Pattern maximum is on two diagonals, 300-deg for High Freqs and 335-deg for Low Freqs. There are significant Gain Holes on the opposite Diagonals (40-60 & 220-240 degrees). Across all angles and frequencies, Raw Gain ranges from -13 to +1.4 dB (Horizontally Polarized). SWR (75-ohms) is 1.8-3.2 with minimum mid-band, however SWR (300-ohms) is 3.5 dropping to 1.6, so either may be used. Date(s): 21 Dec 2011. Album by holl_ands. 1 - 17 of 17 Total. 5010 Visits.
enlarge 71KB, 1024x778 1 FM Turnstile 51.5-in Quasi-Omni 3D View Study this diagram very carefully to determine diagonal direction for Max Gain. enlarge 111KB, 1152x367 2 FM Turnstile 51.5-in Quasi-Omni "Front" View [1 big box = 5-inches] enlarge 252KB, 1024x969 3 FM Turnstile 51.5-in Quasi-Omni Top View [1 big box = 5-inches] enlarge 148KB, 1152x584 4 FM Turnstile 51.5-in Quasi-Omni FM Raw Gain FORWARD (Horiz. Pol.) enlarge 136KB, 1152x584 5 FM Turnstile 51.5-in Quasi-Omni FM Raw Gain to "SIDE" (0-deg) enlarge 138KB, 1152x584 6 FM Turnstile 51.5-in Quasi-Omni FM Raw Gain on 300-deg Diagonal Max on High Freqs enlarge 154KB, 1152x584 7 FM Turnstile 51.5-in Quasi-Omni FM Raw Gain on 300-deg Diagonal Max on Low Freqs enlarge 167KB, 1152x584 8 FM Turnstile 51.5-in Quasi-Omni FM SWR (75-ohms) is 1.8-3.2 enlarge 167KB, 1152x584 9 FM Turnstile Quasi-Omni FM SWR (300-ohms) is 3.5-1.6 enlarge 155KB, 1152x584 10 FM Turnstile Quasi-Omni FM Impedance enlarge 118KB, 1152x385 11 FM Turnstile Quasi-Omni "Side" View [1 big box = 5-inches] enlarge 26KB, 791x1024 12 FM Turnstile Quasi-Omni 4nec2 File enlarge 327KB, 1024x1024 13 FM Turnstile Quasi-Omni Azimuthal Pattern at 87 MHz enlarge 326KB, 1024x1024 14 FM Turnstile Quasi-Omni Azimuthal Pattern at 91 MHz enlarge 321KB, 1024x1024 15 FM Turnstile Quasi-Omni Azimuthal Pattern at 97 MHz enlarge 320KB, 1024x1024 16 FM Turnstile Quasi-Omni Azimuthal Pattern at 103 MHz enlarge 320KB, 1024x1024 17 FM Turnstile Quasi-Omni Azimuthal Pattern at 108 MHz
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