80/40/30 m Dipole

For the lower bands I am using a 40/80 m trap dipole. In order to become qrv on 30 m, I added a radiation coupled lambda/2 element for 30 m, using 10 cm spreader. After cutting the additional wire to the right length, the resonance on 30 m is exactly at 10.1 MHz. The additional element has no influence on the resonance for 40 and 80 m, but the impedance on 30 m is with 150 Ohm significant higher than 50 Ohm.

VSWR_30m
10.1 MHz Impedance (141 – j34) Ohm – VSWR 3
40m_VSWR
7.1 MHz Impedance (40 + j1) Ohm – VSWR 1.24
80m_VSWR
3.6 MHz Impedance (27 – j5) Ohm – VSWR 1.9

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