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.