Above the freespace Azimuth plot
Above the freespace elevation plot
Above the SWR response
Above the elevation pattern when placed 11 meters above average ground conditions
Above the elevation pattern when placed 18 meters above average ground conditions
Above the Gain / Front to back and Front to rear versus frequency.
If the Q factor is below 15 over a wide range of frequencies above and below the operating band, these
are very good stable antennas.
Q factors between 15 and 30 over a wide range of frequencies above and below the operating range
represent acceptable values for slightly less stable antennas.
Q factors between 30 and 50 indicate that they are relatively unstable antennas, although often in some
narrow part of the range they can have a lower Q factor.
Q factors over 50, regardless of the possible narrow parts of the lower Q band, represent extremely
unstable antennas. (SOURCE: YU1AW)
For: 11 meter and 10m band
Antenna Type: 4 elements F-Yagi
Folded dipole Yagi.
Designed by: 19DX348 version 1.01 feb 2014
Boom length: 3,55 Meter
Gain: 8,348 dBI (@27,555 MHz, Peak gain: )
FB <26 dB
FR <26 dB
Impedance: 50 ohms, direct fed
SWR below 1:1.1 > 350 Khz.
SWR below 2:1 > 900 Khz
Element Dimensions:
The center of each element is 22mm and 3 meter long the element tips are 18mm.
Do not change dimensions and be VERY precise !
The distance of the folded dipole is 13cm.
If you use 50mm boom and standard U-Bolts,5mm thick element plates and stauff element clamps you will have 13cm seperation.
Here is an example of how I made it :
ELEMENT DISTANCES and LENGHTS
Element lengths: Distances:
Reflector: 5,550 M 0,0 M
Radiator: 5,286 M 0,440 M (13 cm seperation)
Director 1: 5,188 M 1,270 M
Director 2: 4,760 M 3,550 M
The antenna is 50 Ohms direct fed, no machting losses
A 1;1 balun and / or RF-choke is a must on any Yagi !