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holl_ands | Home > Gray-Hoverman Antennas > Browse:Hoverman Type1 (NO Reflector)Hoverman Type 1 Omni-directionalR-S Catalog Hoverman Type 2 - 4 ReflRodsSBGH - NO Reflector by AutofilsAntennacraft G-1483 Hoverman Type 2Antennacraft SuperG-1483Antennacraft Double-SuperG-1483Lo+Hi-VHF SBGH w NARODSSBGH Hi-VHF & UHF Combo - X0255/6DBGH Hi-VHF & UHF ComboSBGH Wide Beamwidth/Omni Investigations DBGH Wide Beamwidth/Omni Investigations
DBGH Hi-VHF & UHF Combo DBGH (Double Bay Gray Hoverman) with 28 Reflector RODs (3/8-in O.D.).  Combo Hi-VHF & UHF Antenna Simulation Runs using 4nec2. Antenna Design and original EZNEC file posted by <300ohm> on 16Jan2009 to http://www.digitalhome.ca/forum/showthread.php?t=99907 Slides 7-15 are UHF Band Performance.  They illustrate the need to use BARE WIRE (vice Insulated) for UHF Band. Above Ch47 had both Raw Gain Loss and additional Net Gain Loss due to SWR degradation. Slides 16-24 are Hi-VHF Performance.  Insulation had only minor impact...and actually IMPROVED CH7. However, these detriments could appear in different forms in other designs... Note poor F/B and F/R on all Hi-VHF except Ch9 & 10.  Element placement can be changed to reoptimize for either Ch7-8 or Ch11-13. UPDATE 31Jan2009: Due to (inches vs meters) error in defining insulation thickness in 4nec2 file, updated all runs. Date(s): 31 Jan 2009 (UPDATE). Album by holl_ands. 1 - 28 of 28 Total. 1410 Visits.
enlarge 0KB, 594x1024 1 DBGH with 28 RODs (3/8-in O.D.) - 3D View enlarge 0KB, 313x1024 2 DBGH with 28 RODs - Side View Small Box = 1 inch enlarge 0KB, 518x1024 3 DBGH with 28 RODs - Front View Small Box = 1 inch enlarge 8KB, 791x1024 4 4nec2 File: DBGH with 28 Reflector Rods No Insulation on Wires or Reflector Rods. enlarge 9KB, 791x1024 5 4nec2 File: DBGH with 28 Reflector Rods Insulation on Vertical Zig-Zag Wires (only). No Insulation on Reflector Rods. enlarge 10KB, 791x1024 6 4nec2 File: DBGH with 28 Reflector Rods Insulation on all AWG10 Wires. No Insulation on Reflector Rods. enlarge 167KB, 1024x793 7 DBGH with 28 Reflector Rods No Insulation on Wires or Reflector Rods. 3D Total Gain Pattern at 590 MHz enlarge 165KB, 1024x793 8 DBGH with 28 Reflector Rods No Insulation on Wires or Reflector Rods. 3D Horizontal Polarized Gain Pattern at 590 MHz enlarge 153KB, 1024x793 9 DBGH with 28 Reflector Rods No Insulation on Wires or Reflector Rods. 3D Vertical Polarized Gain Pattern at 590 MHz enlarge 0KB, 1024x819 10 300ohm's DBGH with 28 RODS - UHF Gain Ch14-51 Center Freqs are 473-695 MHz Ch52-69 Center Freqs are 701-803 MHz enlarge 0KB, 1024x819 11 300ohm's DBGH with 28 RODS - UHF SWR Keep clicking on image to see higher rez. Click on "X" as usual to exit window. enlarge 0KB, 1024x819 12 300ohm's DBGH with 28 RODS - UHF Impedance All Wires and Reflector RODS are Bare. enlarge 0KB, 1024x819 13 300ohm's DBGH with 28 RODS - UHF Gain PVC Insulation on Vertical Zig-Zags (only). Raw Gain decreases above Ch47. enlarge 0KB, 1024x819 14 300ohm's DBGH with 28 RODS - UHF SWR PVC Insulation on Vertical Zig-Zags (only). Above Ch47, excessive SWR further degrades Net Gain. enlarge 0KB, 1024x819 15 300ohm's DBGH with 28 RODS - UHF Impedance PVC Insulation on Vertical Zig-Zags (only). [45 mil thickness, 3.5 Dielectric Constant] All Reflector RODS (3/8-in O.D.) are Bare. enlarge 0KB, 1024x819 16 300ohm's DBGH with 28 RODS - UHF Gain PVC Insulation on all AWG10 wires. Raw Gain decreases above Ch47. Low freq Gain dip due to Insulation on Feedline. enlarge 0KB, 1024x819 17 300ohm's DBGH with 28 RODS - UHF SWR PVC Insulation on all AWG10 wires. Above Ch47, excessive SWR further degrades Net Gain. enlarge 0KB, 1024x819 18 300ohm's DBGH with 28 RODS - UHF Impedance PVC Insulation on all AWG10 wires. [45 mil thickness, 3.5 Dielectric Constant] All Reflector RODS (3/8-in O.D.) are Bare. enlarge 0KB, 1024x819 19 300ohm's DBGH with 28 RODS - Hi-VHF Gain All Bare Wire & Rods. enlarge 0KB, 1024x819 20 300ohm's DBGH with 28 RODS - Hi-VHF SWR All Bare Wire & Rods. enlarge 0KB, 1024x819 21 300ohm's DBGH with 28 RODS - Hi-VHF Impedance All Wires & Reflector RODS are Bare. enlarge 0KB, 1024x819 22 300ohm's DBGH with 28 RODS - Hi-VHF Gain PVC Insulation on Vertical Zig-Zags (only). Minimal effect on Raw Gain. enlarge 0KB, 1024x819 23 300ohm's DBGH with 28 RODS - Hi-VHF SWR PVC Insulation on Vertical Zig-Zags (only). Minimal SWR impact. enlarge 0KB, 1024x819 24 300ohm's DBGH with 28 RODS - Hi-VHF Impedance PVC Insulation on Vertical Zig-Zags (only). All Reflector RODS (3/8-in O.D.) are Bare. enlarge 0KB, 1024x819 25 300ohm's DBGH with 28 RODS - Hi-VHF Gain PVC Insulation on all AWG10 wires. Minimal effect on Raw Gain, although Ch7 IMPROVED. enlarge 0KB, 1024x819 26 300ohm's DBGH with 28 RODS - Hi-VHF SWR PVC Insulation on all AWG10 wires. Minimal SWR impact. Note SWR DECREASE at lowest frequencies. enlarge 0KB, 1024x819 27 300ohm's DBGH with 28 RODS - Hi-VHF Impedance PVC Insulation on all AWG10 wires. All Reflector RODS (3/8-in O.D.) are Bare. enlarge 247KB, 791x1024 28 300ohm's DBGH with 28 RODS - pdf Drawing Note L1 & L2 choices for optimum Gain on Ch7, 9 or 13 ["reflectors are yellow"]
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