• Public Gallery  • Help
		• Join Now!  • Log In  • Feature Tour

holl_ands | Home > Yagi Antennas > Browse:Yagi Comparison ChartsUHF 2-El FD-Yagi - OPTimizedUHF 3-El FD-Yagi - OPTimized UHF 4-El FD-Yagi - OPTimizedUHF 5-El FD-Yagi - OPTimized UHF 5-El FLAT Yagi - CM-4040UHF 6-El FD-Yagi - OPTimizedUHF 6-El Asymmetric Dipole Yagi - WA5VJBUHF 7-El FD-Yagi - OPTimizedUHF 7-El FD-Yagi - Opt. by NikimlUHF 8-El FD-Yagi (2ReflRods) - OPTimizedUHF 8-El FLF-Yagi - 300ohm OPTimizedUHF 12-El FD-Yagi - OPTimizedUHF 13-El FD-Yagi (2ReflRod) - OPTimizedUHF 13-El FD-Yagi (2RR) EqualDirs - OPTUHF 13-El FD-Yagi (2ReflRods) - kgbUHF CM4248 15El FD-Yagi + 14RR CornerUHF 16-El Yagi + 6RR Corner Wade CYD1446UHF 17-El Yagi with 6RR's - tfrlicUHF 18-El FD-Yagi (2ReflRods) - OPTUHF 18-El Yagi from snowman53UHF 25-El FD-Yagi (2ReflRods) - OPTUHF 91XG Corner-FD-YagiUHF 91XG - Wider Corner ReflectorUHF 91XG - Wider Bowties, Better Ch14-51UHF 91XG - Taller Corner ReflectorCh14-17 15El FD-Yagi + 14RR Corner - OPTCh14-17 18El FD-Yagi + 10RR Corner - OPTCh14-17 18El FD-Yagi + 14RR Corner - OPTCh14-17 18El FD-Yagi + 20RR Corner - OPTCh14-19 18El FD-Yagi + 20RR Corner - OPTCh14-19 21El FD-Yagi + 20RR Corner - OPTCh22 9-El FD-Yagi - 300ohm OPTimizedCh22 9-El FLF-Yagi - 300ohm OPTimizedCh22 9-El FD-Yagi - 75ohm MTM ScientificCh22 9-El FD-Yagi - 300ohm K7MEMCh22 11-El FD-Yagi - 300ohm K7MEMCh30 18El FD-Yagi + 14RR CornerCh45-51 12-El FD-Yagi - OPTimizedHi-VHF 3-El FD-Yagi - OPTimizedHi-VHF 3-El One-Lamda LFA-YagiHi-VHF 4-El FD-Yagi - OPTimizedHi-VHF 4-El FLF Yagi - OPTimizedHi-VHF 4-El K7MEM Yagi: Folded vs NotHi-VHF 5-El FD-Yagi - OPTimizedHi-VHF 5-El FLF Yagi - OPTimizedHi-VHF 5-El Yagi Optimized by K6STIHi-VHF 6-El FD-Yagi - OPTimizedHi-VHF 7-El FD-Yagi - OPTimizedHi-VHF 8-El K7MEM Yagi: Folded vs NotHi-VHF 8-El FD-Yagi - OPTimizedHiVHF 9-El FD-Yagi - 1 vs 3 Refl. RodsHiVHF 9-El FD-Yagi, Stellar Labs 30-2475Hi-VHF 10-El FD-Yagi - OPTimizedHi-VHF 10-El FD-Yagi - Lorkoe's AntiqueHi-VHF 12-El FD-Yagi - OPTimizedHi-VHF 12-El FD-Yagi (3ReflRods) - kgbHiVHF 13El FD-Yagi - Stellar Labs 302476Hi-VHF 13-El FD-Yagi (2ReflRods) - kgbHi-VHF 16-El FD-Yagi - OPTimizedHi-VHF 18-El FD-Yagi - OPTimizedHi-VHF 20-El FD-Yagi - OPTimizedHi-VHF 22-El FD-Yagi - OPTimizedCh13 5-El Yagi - OPTimized by nikimlCh13 8-El Yagi - OPTimized by K6STICh13 12-El FD-Yagi - OPTimizedCh12 12-El FD-Yagi - OPTimized Ch6 2-El FD-Yagi - OPTimizedCh6 3-El FD-Yagi - OPTimizedCh7 12-El Yagi from v37bqhCh2-6 Antennacraft Y5-2-6 5-El FD-YagiCh3 4-El FD-Yagi - OPTimizedCh3 5-El FD-Yagi - OPTimizedCh3 6-El FD-Yagi - OPTimized
Ch22 9-El FD-Yagi - 300ohm K7MEM Ch22 9-Element Folded Dipole Yagi (518-524 MHz) analyzed using 4nec2 [see *.nec.doc file below]. Design Dimensions from rabbit73 post for 11-El Yagi (see last Image), and K7MEM Design for 9-El simply drops two front Directors.  Calculated using fol. K7MEM Website: http://www.k7mem.com/Electronic_Notebook/antennas/yagi_vhf.html Note that K7MEM Dimensions [for Cutting Elements] must be SHORTENED by the "Boom Correction" = BC * Element Diameter, when 4nec2 Model is constructed WITHOUT the METAL Boom, where BC=0.666. Boom Correction for ACTIVE Element is derated by 50% due to being mounted ABOVE the Boom. Ch22 9-El FD-Yagi - 300-ohm K7MEM: Ch22 Raw Gain = 13.3 to 13.4 dBi, F/B & F/R Ratio Min. = 14.3 dB and SWR (300-ohms) = Under 1.4. BOOM LENGTH = 1045-mm (41-1/8 inches). Unfortunately, K7MEM (like other "Formula Driven" Designs), are NOT OPTIMIZED [poor F/B & F/R Ratios]. Although Gain Curve was VERY FLAT, F/B & F/R Ratios were Best well away from desired 518-524 MHz and SWR Curve for 200-ohms is better than 300-ohms, although Both are "Acceptable" [not always true]. Compare to OPTIMIZED Designs for similar 9-El Yagis: use pull-down Navigation Menu above: Ch22 9-El FD-Yagi - 300ohm OPTimized: Ch22 Raw Gain = 12.7 to 12.9 dBi, F/B & F/R Ratio Min. = 26.4 dB and SWR (300-ohms) Under 2.2. BTW: Gain for Optimized 75-ohm FD-Yagi was not quite as Good.  And note that F/B & F/R Ratios could be improved at the expense of a small amount of Forward Gain and/or slightly higher SWR. Ch22 9-El FLF-Yagi [Flat-Loop-Fed] - 300ohm OPTimized: Ch22 Raw Gain = 13.2 to 13.4 dBi, F/B & F/R Ratio Min. = 40.2 dB and SWR (300-ohms) Under 1.7. Date(s): 3 Jul 2016. Album by holl_ands. 1 - 15 of 15 Total. 2047 Visits.
enlarge 53KB, 1011x1024 1 Ch22 9-El FD-Yagi - 300ohm K7MEM 3D View enlarge 120KB, 1152x401 2 Ch22 9-El FD-Yagi - 300ohm K7MEM Front View [1 large square = 1.25 inches] enlarge 178KB, 1152x650 3 Ch22 9-El FD-Yagi - 300ohm K7MEM Top View [1 large square = 12.5 inches] enlarge 228KB, 1152x703 4 Ch22 9-El FD-Yagi - 300ohm K7MEM UHF Raw Gain is Maximum near 521 MHz UHF F/B & F/R Ratios are MINIMUM!!! near 521 MHz and MAXIMUM away from 521 MHz. enlarge 238KB, 1152x703 5 Ch22 9-El FD-Yagi - 300ohm K7MEM UHF SWR (300-ohms) is Minimum near 521 MHz enlarge 223KB, 1152x703 6 Ch22 9-El FD-Yagi - 300ohm K7MEM UHF SWR (200-ohms) is Significantly LOWER than 300-ohms enlarge 302KB, 1024x1024 7 Ch22 9-El FD-Yagi - 300ohm K7MEM Azimuthal Pattern at 518 MHz enlarge 302KB, 1024x1024 8 Ch22 9-El FD-Yagi - 300ohm K7MEM Azimuthal Pattern at 521 MHz enlarge 306KB, 1024x1024 9 Ch22 9-El FD-Yagi - 300ohm K7MEM Azimuthal Pattern at 524 MHz enlarge 30KB, 791x1024 10 Ch22 9-El FD-Yagi - 300ohm K7MEM 4nec2 File includes Summary of Dimensions enlarge 32KB, 791x1024 11 Ch22 9-El FD-Yagi - 300ohm K7MEM EVAL Summary of Performance enlarge 168KB, 791x1024 12 Ch22 9-El FD-Yagi - 300ohm K7MEM EVAL *.html Performance Summary enlarge 307KB, 1024x1024 13 Ch22 9-El FD-Yagi - 300ohm K7MEM Elevation Pattern at 521 MHz Elevation Beamwidth = 44-deg [NOTE: BW on Chart needs to be DOUBLED.] enlarge 62KB, 1152x215 14 Ch22 9-El FD-Yagi - 300ohm K7MEM Side View [1 large square = 12.5 inches] enlarge 173KB, 1152x599 15 Ch22 9-El FD-Yagi - 300ohm K7MEM rabbit73 Post for K7MEM 11-El Yagi Design Design for 9-El Yagi is SAME w/o 2 Directors
Select All.
Sign the Guestbook. There are no entries.