FM Double-Hoop + Vertical-Folded-Dipole In Center analyzed using 4nec2.
This antenna responds to Horizontal and Vertical Polarization, with a Horizontal Gain of -5.2 to +0.8 dBi. Vertical Whip max was +1.2 dBi with a -10 dBi Gain hole on lower freqs for Vertically Polarized signals.
Total Gain (Vert. + Horiz.) remained between -1.8 and +2.3 dBi across all angles and frequencies. However, users may be unhappy with performance if a station is only transmitting Vertical Polarity. SWR (300-ohms) was 2.2-7.2.
23 Dec 201118 items4721 visitsAlbum by holl_ands
enlarge 53KB, 615x1024 1 Double-Hoop + Vertical-Folded-Dipole-In-Center 3D View
enlarge 124KB, 379x1024 2 Double-Hoop + Vertical-Folded-Dipole-In-Center Side View [1 big box = 5-inches]
enlarge 267KB, 1024x994 3 Double-Hoop + Vertical-Folded-Dipole-In-Center Top View [1 big box = 2.5-inches]
enlarge 87KB, 1024x890 4 Double-Hoop + Vertical-Folded-Dipole-In-Center 3D View DETAIL
enlarge 199KB, 1024x784 5 Double-Hoop + Vertical-Folded-Dipole-In-Center Side View DETAIL [1 big box = 2.5-inches]
enlarge 115KB, 386x1024 6 Double-Hoop + Vertical-Folded-Dipole-In-Center Front View [1 big box = 5-inches]
enlarge 156KB, 1152x584 7 Double-Hoop + Vertical-Folded-Dipole-In-Center FM Raw Total Gain FORWARD (90-deg)
enlarge 149KB, 1152x584 8 Double-Hoop + Vertical-Folded-Dipole-In-Center FM Total Raw Gain to REVERSE (270-deg) Slightly HIGHER than Forward Gain, esp High Freqs.
enlarge 145KB, 1152x584 9 Double-Hoop + Vertical-Folded-Dipole-In-Center FM Total Raw Gain to SIDE (0-deg) Horizontal + Vertical Gain only has small Total Gain loss.
enlarge 179KB, 1152x584 10 Double-Hoop + Vertical-Folded-Dipole-In-Center FM SWR (300-ohms) is 7.2-2.2
enlarge 189KB, 1152x584 11 Double-Hoop + Vertical-Folded-Dipole-In-Center FM SWR (75-ohms) is 1.7-11.6
enlarge 148KB, 1152x584 12 Double-Hoop + Vertical-Folded-Dipole-In-Center FM Impedance
