Low Q Yagis - G4CQM - 2017

Why Low Q?...

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4nec2 - Geo - EF02094nec2 - Geo - CQM9C4
4nec2 - Geo - EF02094nec2 - Geo - CQM9C4

Because yagis exhibit a frequency response similar to that of a Low Pass Filter (LPF), it is most important to ensure that the cut-off frequency is well above the desired upper bandwidth limit! Seen here is a direct comparison using Arie Voors 4nec2 software, looking at YU7EF EF0209 and G4CQM CQM9C4, both of similar boom length. Keeping reactance down and within tighter limits will deliver a more stable outcome and most likely to secure results predicted in software. Low Q is the way to go!

EF0209 SWRCQM9C4 SWR
EF0209 SWRCQM9C4 SWR

 

EF0209 ImpedanceCQM9C4 Impedance
EF0209 ImpedanceCQM9C4 Impedance

 

TANT - EF0209 - Single YagiTANT - CQM9C4 - Single Yagi
TANT - EF0209 - Single YagiTANT - CQM9C4 - Single Yagi

 

EF0209 - Average Q-factor = 31.3CQM9C4 - Average Q-factor = 9.4
Average Q-factorAverage Q-factor

Files...

EF0209.nec

CQM9C4.nec


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