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holl_ands | Home > Loop Antennas incl Folded Dipole > Browse:Compare LoopsWi-Fi Folded Dipole - 2400-2500 MHzUHF Folded & Tri-Folded DipolesHi-VHF+UHF "VEE" Folded DipoleUHF Circular & Square Loops NO ReflectorUHF "Figure-8" Twin Loops - NO ReflUHF "Figure-8" Twin-Loops + xxRR - OPTHi-VHF Figure-8 Twin Loops - NO ReflUHF Twin-Hoop Chireix - NO or 26ReflRodsHi-VHF+UHF Tapered Loop - A-D C2 & C2-VHi-VHF+UHF Tapered DoubleLoop - d510d180UHF Shorted Bowtie Loop (SBL)Hi-VHF+UHF Bowtie-In-Loop - NO ReflectorHi-VHF+UHF Bowtie-In-Loop + 11RR - OPTHi-VHF+UHF Bowtie-In-Loop (DblAngRefl)HiVHF+UHF DreamcatcherU+H 2-Bay Hentenna NO+11ReflRodsUHF Hourglass LoopUHF Quad-Trapezoid-LoopUHF Quad-Trapezoid-Loop+2xBarsUHF Quadazoid Loop - No ReflUHF Quadazoid Loop + ReflectorHi-VHF Folded DipolesHi-VHF Circular Loop + ReflectorHi-VHF Square Loop + ReflectorHiVHF Shorted Bowtie Loop (NO Reflector)Hi-VHF Shorted Bowtie Loop (w Reflector)Hi-VHF Hourglass LoopHi-VHF Quad-Trapezoid-LoopHi-VHF Quad-Trapezoid-Loop+2Bars - OPTLo-VHF Tri-Folded Dipoles - OPTLo-VHF 2-Bay Folded Dipole - OPTVHF Square & Circular LoopsLo-VHF Folded DipolesLoVHF Hourglass-Loop - No ReflectorLoVHF+FM Hourglass LoopLoVHF Hourglass-Loop + 3 ReflRodsLoVHF Hourglass-Loop + 5 ReflRodsHi-VHF (+UHF) Twin Rectangular LoopsHiVHF+UHF RL-M2 2-Bay+Loop - NO Refl.H+U 2-Bay+Loop RLH2 (12x10) - NO ReflH+U 2-Bay+Loop RLH2 (10.5x8.7) - NO ReflH+U 4-Bay Loop RLH4 - No ReflHiVHF+UHF 2Square-Chireix-In-Rect. LoopHi-VHF+UHF In 3-ftx2-ft Picture Frame/
Lo-VHF Folded Dipoles VHF Folded Dipoles, including specifically for Ch2-6, Ch2-FM, only Ch6 and only FM, analyzed using 4nec2. Includes Omnidirectional Vertical Dipole for FM Band, but see OMNIDIRECTIONAL album for more info. Example 4nec2 files included for most antennas. Some DIY Folded Dipole examples: oldsyd's (new) Ch7: http://img4.imageshack.us/img4/6002/foldeddipole1.jpg oldsyd's (old) Ch7: http://img23.imageshack.us/img23/180/0000241.jpg mlord's Ch6: http://www.digitalhome.ca/forum/showthread.php?p=833571 Note that even HICT (Half-Inch Copper Tubing) is NOT FAT ENOUGH to provide "acceptable" SWR [i.e. Under 2.7 so Mis-match Loss under 1.0 dB] for ENTIRE Lo-VHF Band (Ch2-6),  but is just slightly over SWR = 2.7 for Ch3-6.  And small, AWG24 wire size [such as is used in 300-ohm Twin-lead] was only suitable for SINGLE CHANNEL Antennas. There is a Quasi-Optimum Separation between Folded Dipole Elements of about two inches for larger diameters, one inch for moderate and 1.0 to 0.5 inch for small wires.  But a 2:1 variation causes only small differences in SWR. Optimized Folded Dipole sizes are: 63.0 x 2.0 inch - 0.569-in (Type M) Copper Tubing (Ch6, also OK for CH5 and FM Band) 63.4 x 2.0 inch - 0.25-in O.D. Copper Wire (Ch6, but SWR high for CH5 & FM Band). 64.0 x 2.0 inch - AWG10 Copper Wire (Ch6, but SWR too high for CH5 & FM Band). 64.0 x 3.0 inch - AWG12 Copper Wire (Ch6, but SWR too high for CH5 & FM Band). 65.5 x 0.5 inch - AWG12 Copper Wire (Ch6, but SWR too high for CH5 & FM Band). 66.2 x 0.5 inch - AWG24 Copper Wire (Ch6, but SWR too high for CH5 & FM Band). [Reduce length by velocity factor if using 1/2-in Twinlead.] 76.0 x 2.5 inch - 0.569-in (Type M) Copper Tubing (Ch3-6, although SWR high on Ch3 & Ch6) 82.0 x 2.5 inch - 0.569-in (Type M) Copper Tubing (Ch2-6, although SWR high on Ch2 & Ch6) 99.24 x 0.5 inch - AWG24 Copper Wire (Ch2 ONLY) [Reduce Length by Velocity Factor if using 1/2-inch Twinlead.] Optimum size for an almost OMNIDIRECTIONAL VERTICAL Folded Dipole for just the FM Band is 53.0 x 8.0 inch using 0.569-in O.D. Copper Tubing.  Gain away from feedpoint is 2.6 dBi and 1.4 dBi in opposite direction. A clamp can be attached to the center of the long element since it is at zero ground potential. Alternative size for Horizontal or Vertical FM Folded Dipole is 55-in x 4-in.  Both use Feedpoint Gap=1.25-in. Folded Dipoles for FM Band frequently come with a Receiver: http://kgnu.org/ht/helpfm.html Here's an on-line Folded Dipole Calculator: http://www.k7mem.com/Electronic_Notebook/antennas/folded_dipole.html Note that IF element diameters are the same, impedance does not change as you vary the separation. By adding a Reflector and a Director, you've got a simple 3-Element YAGI: http://www.wfu.edu/~matthews/misc/dipole.html EDIT (22Nov2012): Moved Ch6 and Vertical FM Charts to this new Album from Hi-VHF Folded Dipole album. Added analysis of optimized sizes for Ch2-6 and Ch3-6 Folded Dipoles. EDIT (13Jun2013): Added Ch2 (ONLY) Folded Dipole using AWG24 (e.g. 1/2-in Twinlead). EDIT (9May2018): Added Ch6 (ONLY) Folded Dipole using AWG10 and QICT. Date(s): 22 Nov 2012. Album by holl_ands. 1 - 38 of 38 Total. 14598 Visits.
enlarge 147KB, 1024x748 1 CH6 Folded Dipole - Net Gain for Different Diameters 1/2-in Copper (Type M) Tubing is good for CH6 and "adequate" for Ch5 + FM Band. AWG12 & AWG24 good only across Ch6. enlarge 146KB, 1024x748 2 CH6 Folded Dipole - SWR for Different Diameters 1/2-in Copper (Type M) Tubing is good for CH6 and "adequate" for Ch5 + FM Band. AWG12 & AWG24 good only across Ch6. enlarge 297KB, 1024x1019 3 Vertical Folded Dipole for FM Band Slightly more Gain away from the Feedpoint. enlarge 179KB, 1152x692 4 Ch6 Folded Dipole 0.569-in O.D. Ch2-FM Raw Gain 63-inches x 2.5 inch Separation up to 3 inches with minimal impact. enlarge 216KB, 1152x692 5 Ch6 Folded Dipole 0.569-in O.D. Ch2-FM SWR (300-ohms) 63-inches x 2.5 inch enlarge 259KB, 1152x692 6 Ch6 Folded Dipole 0.569-in O.D. Ch2-FM Impedance 63-inches x 2.5 inch enlarge 179KB, 1152x692 7 Ch6 Folded Dipole 0.569-in O.D. Ch2-13 Raw Gain 63-inches x 2.5 inch NOT also suitable for Hi-VHF Band. enlarge 221KB, 1152x692 8 Ch6 Folded Dipole 0.569-in O.D. Ch2-13 SWR (300-ohms) 63-inches x 2.5 inch NOT also suitable for Hi-VHF Band. enlarge 283KB, 1152x692 9 Ch6 Folded Dipole 0.569-in O.D. Ch2-13 Impedance 63-inches x 2.5 inch NOT also suitable for Hi-VHF Band. enlarge 0KB, 1024x819 10 CH6 Folded Dipole 0.569-in O.D. - Raw Gain 63-inches x 1 inch Separation up to 3 inches with minimal impact. enlarge 0KB, 1024x819 11 CH6 Folded Dipole 0.569-in O.D. - SWR enlarge 0KB, 1024x819 12 CH6 Folded Dipole 0.569-in O.D. - Impedance enlarge 157KB, 1152x692 13 Ch3-6 Folded Dipole 0.569-in O.D. Ch2-6 Raw Gain 76-inches x 3 inch enlarge 207KB, 1152x692 14 Ch3-6 Folded Dipole 0.569-in O.D. Ch2-6 SWR (300-ohms), excessive on Ch2 76-inches x 3 inch enlarge 241KB, 1152x692 15 Ch3-6 Folded Dipole 0.569-in O.D. Ch2-6 Impedance 76-inches x 3 inch enlarge 158KB, 1152x692 16 Ch2-6 Folded Dipole 0.569-in O.D. Ch2-6 Raw Gain 82-inches x 3 inch enlarge 203KB, 1152x692 17 Ch2-6 Folded Dipole 0.569-in O.D. Ch2-6 SWR (300-ohms), high on Ch2 & 6 82-inches x 3 inch enlarge 249KB, 1152x692 18 Ch2-6 Folded Dipole 0.569-in O.D. Ch2-6 Impedance 82-inches x 3 inch enlarge 188KB, 1152x701 19 CH3 Folded Dipole AWG24 [e.g. Twinlead] Ch3 Raw Gain = 2.1 to 2.2 dBi 89.75-inches x 0.5 inch Separation up to 1.0 inches with minimal impact. enlarge 231KB, 1152x701 20 CH3 Folded Dipole AWG24 [e.g. Twinlead] Ch3 SWR (300-ohms) Under 2.0 enlarge 273KB, 1152x701 21 CH3 Folded Dipole AWG24 [e.g. Twinlead] Ch3 Impedance enlarge 169KB, 1152x678 22 CH2 Folded Dipole AWG24 [e.g. Twinlead] Ch2-6 Raw Gain = 2.1 to 2.8 dBi 99.25-inches x 0.5 inch Separation up to 1.0 inches with minimal impact. enlarge 202KB, 1152x678 23 CH2 Folded Dipole AWG24 [e.g. Twinlead] Ch2 SWR (300-ohms) Under 2.2 99.25-inches x 0.5 inch enlarge 247KB, 1152x678 24 CH2 Folded Dipole AWG24 [e.g. Twinlead] Ch2-6 Impedance 99.25-inches x 0.5 inch enlarge 43KB, 1024x691 25 Ch6 Folded Dipole AWG10 3D View enlarge 91KB, 1152x261 26 Ch6 Folded Dipole AWG10 Front View 64.0-inches x 2.0 inch enlarge 27KB, 791x1024 27 CH6 Folded Dipole AWG10 4nec2 text File includes Dimensions enlarge 178KB, 1152x664 28 Ch6 Folded Dipole AWG10 Ch6 (82-88 MHz) Raw  Gain = 2.1 to 2.1 dBi enlarge 207KB, 1152x664 29 Ch6 Folded Dipole AWG10 Ch6 (82-88 MHz) SWR (300-ohms) = 1.4 to 1.1 to 1.4 enlarge 229KB, 1152x664 30 Ch6 Folded Dipole AWG10 Ch6 (82-88 MHz) Impedance enlarge 315KB, 1024x1024 31 Ch6 Folded Dipole AWG10 Azimuthal Pattern at 82 MHz enlarge 316KB, 1024x1024 32 Ch6 Folded Dipole AWG10 Azimuthal Pattern at 85 MHz enlarge 316KB, 1024x1024 33 Ch6 Folded Dipole AWG10 Azimuthal Pattern at 88 MHz enlarge 296KB, 1024x1024 34 Ch6 Folded Dipole AWG10 Elevation Pattern at 82 MHz enlarge 297KB, 1024x1024 35 Ch6 Folded Dipole AWG10 Elevation Pattern at 85 MHz enlarge 297KB, 1024x1024 36 Ch6 Folded Dipole AWG10 Elevation Pattern at 88 MHz enlarge 28KB, 791x1024 37 Ch6 Folded Dipole AWG10 EVAL Performance Summary text File enlarge 30KB, 791x1024 38 Ch6 Folded Dipole AWG10 EVAL Performance Summary *.html File
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