Hairpn modified antenna for 40 m band – improvments and updates (h=5.5 m above the ground)

For ease of adjustment I found that it is necessary to mount a gear for variable air capacitors.

SWR graph - 7050 +/_ 50khz 

Resonant frequency = 7071 khz
Bw (swr<1.5 = 268 khz) Bw (swr<2 = 484 khz )