Here’s an example, You have a 6 meter yagi, 2m yagi and a 70cm yagi stacked on a mast. The 70cm yagi should be 1/2 wave @ 70cm from the 2m yagi. The 2m yagi should be 1/2 wave @ 2m from the 6m yagi. The lower band yagis will not “see” the higher bands. Same goes with mobile antennas. 70cm whip should be 1/2 wave @ 70cm from a 2m whip etc. Dual band whips are using the lowest operating band. Sent using Tapatalk