Low Q Yagis - G4CQM - 2017

Dipoles Explored...

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To create a level playing field the following analysis has been carried out in K6STI's Antenna Optimizer Professional (AOP) version software. Each dipole has been tuned for minimum reactance at 144MHz. The Split Dipole, Folded Dipole and LFA Loop all exhibit their own respective intrinsic impedance. Meanwhile the V Split Dipole can easily be adjusted to 50Ω by simply changing the swept back angle and tuning out reactance by altering length!

Note that the LFA Loop and V Split Dipole exhibit some pattern distortion (not symmetrical) which has an impact on the final overall pattern when located in a yagi build, LFA Loop being worst of all!


 

Split Dipole
Split Dipole

 

Split Dipole in AOPAntenna File - Symbolic Dimensions
Split Dipole in AOPAntenna File - Symbolic Dimensions
AzimuthElevation
AzimuthElevation

 

Split Dipole - Average Q-factor = 4.9
Average Q-factor

 


 

Folded Dipole
Folded Dipole

 

Folded Dipole in AOPAntenna File - Symbolic Dimensions
Folded Dipole in AOPAntenna File - Symbolic Dimensions
AzimuthElevation
AzimuthElevation

 

Folded Dipole - Average Q-factor = 3.2
Average Q-factor

 


 

LFA Loop
LFA Loop

 

LFA Loop in AOPAntenna File - Symbolic Dimensions
LFA Loop in AOPAntenna File - Symbolic Dimensions
AzimuthElevation
AzimuthElevation

 

LFA Loop - Average Q-factor = 2.5
Average Q-factor

 


 

V Split Dipole
V Split Dipole

 

V Split Dipole in AOPAntenna File - Symbolic Dimensions
LFA Loop in AOPAntenna File - Symbolic Dimensions
AzimuthElevation
AzimuthElevation

 

V Split Dipole - Average Q-factor = 7.1
Average Q-factor

 


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