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holl_ands | Home > Bowties, Dipoles, Batwings & Rhombics > Browse:UHF Stick Dipole - No ReflectorUHF Bowties - NO ReflectorUHF Fractal Bowtie - No ReflectorUHF CM4248 Folded Dipole Bowtie (ONLY)91XG Dipole ONLY & Dipole+First DirectorUHF Batwing - No Refl & Screen Grid ReflUHF Small Rhombic StackUHF Double RhomboidVHF Stick Dipoles incl Horiz.Rabbit-EarsHi-VHF+UHF Stick Dipole - No ReflectorHi-VHF+UHF "VEE" Stick DipoleHi-VHF Bowties - No ReflectorLo+Hi-VHF 1-Bay Bowtie - No Reflector
UHF Stick Dipole - No Reflector UHF Stick Dipole analyzed using 4nec2. Characteristic Impedance of 75-ohms resulted in low SWR near 569 MHz, but Excessive SWR at high and low freqs in UHF Band.  [Note that Folded Dipole has much better SWR vs Frequency.] Three additional images illustrate a Fair to Good 300-ohms match results if the Dipole Length is 20-percent longer: Each Whisker=5.27-in with Gap=0.75in for Total WIDTH of 11.29-in, which is a HALF-Wavelength at 523 MHz (just below middle of the band). Note that very FAT sticks are needed to minimize SWR throughout the entire UHF Band. Quarter-Inch-Copper-Tubing (QICT) is analyzed here.  (Half-Inch was difficult to model in 4nec2.) ======================================= Very Wide Band Frequency Sweeps shows FORWARD Gain continues to INCREASE up to about 4.6 dBi at 1425 MHz, at which point the DIAGONAL Gain in the Clover Leaf Azimuthal Pattern takes over, providing about 2 to 4 dBi up through about 2700 MHz, at which point a SIX-LOBE Pattern results in Diagonal Gain (varies from 35-deg to 45-deg) of about 3-4 dBi PLUS Forward Gain of up to about 2 dBi from 3000 to 3500 MHz. Note that with Characteristic Impedance of 75-ohms, the Stick Dipole is "Resonant" (i.e. Zimag=0) at about 630 MHz and reaches lowest SWR at not only near 569 MHz in middle of UHF Band, but ALSO near 1775 MHz (3X Higher) and near 3000 MHz (5.2X Higher).  This behavior is how a single set of Elements, e.g. R-S VU Series, can be designed to cover both Lo-VHF and Hi-VHF Bands. Date(s): 14 Feb 2011. Album by holl_ands. 1 - 34 of 34 Total. 10900 Visits.
enlarge 24KB, 1152x505 1 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" 3D View enlarge 50KB, 1152x193 2 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Front View [1 small box = 0.25 inch] enlarge 30KB, 791x1024 3 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" 4nec2 File enlarge 151KB, 1152x710 4 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" UHF Raw Gain enlarge 198KB, 1152x710 5 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" UHF SWR (75-ohms) EXCESSIVE on high & low channels enlarge 165KB, 1152x710 6 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" UHF Impedance enlarge 321KB, 1024x1024 7 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 470 MHz enlarge 321KB, 1024x1024 8 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 590 MHz enlarge 320KB, 1024x1024 9 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 698 MHz enlarge 148KB, 1024x790 10 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" 3D Total Pattern at 590 MHz enlarge 144KB, 1024x787 11 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" 3D Horiz. Polarization Pattern at 590 MHz enlarge 140KB, 1024x784 12 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" 3D Vertical Polarization Pattern at 590 MHz enlarge 137KB, 1024x686 13 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" UHF Raw Gain enlarge 158KB, 1024x686 14 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" UHF SWR (300-ohms) Under 2.5 ILLUSTRATES BEST 300-OHM MATCH WITH 20-PERCENT LONGER DIPOLE. enlarge 154KB, 1024x686 15 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" UHF Impedance enlarge 159KB, 1024x733 16 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz Raw Gain FORWARD=REVERSE enlarge 197KB, 1024x733 17 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz SWR (75-ohms) enlarge 198KB, 1024x661 18 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz SWR (300-ohms) Note MUCH better SWR enlarge 304KB, 1024x1024 19 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 54 MHz enlarge 304KB, 1024x1024 20 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 90 MHz enlarge 304KB, 1024x1024 21 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 174 MHz enlarge 308KB, 1024x1024 22 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 474 MHz [Ch14] enlarge 308KB, 1024x1024 23 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 569 MHz [Ch30} enlarge 310KB, 1024x1024 24 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 698 MHz [Ch51] enlarge 151KB, 1024x733 25 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz Diagonal (55-deg) Raw Gain enlarge 103KB, 1152x469 26 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz Diagonal (35-deg) Raw Gain enlarge 116KB, 1152x469 27 UHF Stick Dipole, Whiskers=5.27", Gap=0.75" 50-3500 MHz Diagonal (45-deg) Raw Gain enlarge 307KB, 1024x1024 28 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 1000 MHz enlarge 303KB, 1024x1024 29 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 1425 MHz enlarge 324KB, 1024x1024 30 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 1900 MHz enlarge 341KB, 1024x1024 31 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 2150 MHz enlarge 324KB, 1024x1024 32 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 2500 MHz enlarge 337KB, 1024x1024 33 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 3000 MHz enlarge 328KB, 1024x1024 34 UHF Stick Dipole, Whiskers=4.39", Gap=0.75" Total, Horizontal & Vertical Patterns at 3500 MHz
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