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

holl_ands | Home > Parabolic Antennas > Browse:Comparison Charts - ParabolicsCM4251 7-ft Parabolic + 2-Bay Refl FeedCM4251 Parabolic + 4-Wire FBmodCM-4251 Parabolic+FBmod - Bigger 2-BayCM4251 Parabolic+FBmod - Opt. 2-Bay 9-RRCM-4251 Parabolic+FBmod+8-El LPDACM-4251 Parabolic+FBmod+9-El LPDAUHF 2-m Parabolic + 8-El LPDA Feed
CM4251 Parabolic + 4-Wire FBmod UHF Channel Master CM-4251 Parabolic Reflector Antenna with 2-Bay Triangular-Bowtie, minimally modified with 4 additional wires in middle of Reflector (smaller radius material would be acceptable). This old Antenna is STILL designed for the OLD UHF Band (470-806 MHz). Raw Gain was only minimally affected and as expected, there was significant improvement to F/B & F/R Ratios, but very little if any increase on the lower channels. This minimal modification illustrates that significant improvement in F/B & F/R Ratios are possible with minimal increase in wind resistance.  Optimal placement of additional wires should be investigated to determine whether it is better to add say 2 or 3 more wires above and 2 or 3 more below or to extend to the sides more...or both. Date(s): 21 Mar 2013. Album by holl_ands. 1 - 15 of 15 Total. 6657 Visits.
enlarge 130KB, 920x1024 1 CM4251 Parabolic + 4-Wire FBmod 3D View enlarge 242KB, 984x1024 2 CM4251 Parabolic + 4-Wire FBmod Front View [1 large square = 12.5 inches] enlarge 148KB, 603x1024 3 CM4251 Parabolic + 4-Wire FBmod Top View [1 large square = 12.5 inches] enlarge 195KB, 1152x678 4 CM4251 Parabolic + 4-Wire FBmod UHF Raw Gain Max = 20.8 dBi near 800 MHz F/R and esp. F/B Ratios are minimal on low channels enlarge 191KB, 1152x678 5 CM4251 Parabolic + 4-Wire FBmod UHF SWR (300-ohm) Under 2.9 enlarge 246KB, 1152x678 6 CM4251 Parabolic + 4-Wire FBmod UHF Impedance enlarge 302KB, 1024x1024 7 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 470 MHz enlarge 302KB, 1024x1024 8 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 530 MHz enlarge 300KB, 1024x1024 9 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 590 MHz enlarge 300KB, 1024x1024 10 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 650 MHz enlarge 300KB, 1024x1024 11 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 698 MHz enlarge 300KB, 1024x1024 12 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 758 MHz enlarge 301KB, 1024x1024 13 CM4251 Parabolic + 4-Wire FBmod Azimuthal Pattern at 806 MHz enlarge 137KB, 611x1024 14 CM4251 Parabolic + 4-Wire FBmod Side View [1 large square = 12.5 inches] enlarge 94KB, 791x1024 15 CM4251 Parabolic + 4-Wire FBmod 4nec2 File
Select All.
Sign the Guestbook. There are no entries.