If the design is good in the first place (interlaced yagis),there should be no problem.
I am using an interlaced yagi , 2m and 70cm and a *common feedpoint, *that is, no duplexer at the feedpoint a single/common element feed. All elements for both bands are in the same plane.
It was designed to be used that way. It is an EAntenna, 5 EL on 2m, 8 EL on 70cm and it works beautifully on the LEO birds. I run strictly mode B and have the antenna mounted atop a 48' tower and 15' of mast. It is vertically polarized with a fixed 15 deg upltilt (elevation), eliminating the need for an elevation rotor, as the gain at the horizon is only down 1 dB.
Judicious use of Comet duplexers or triplexers as filters works out very well. I can hear myself at an elevation of -0.5 deg easily on nearly all the LEOs. No intermod , no desense because duplexers make such good filters for satellites.
You can see my QRZ page for pictures of the antenna in place at 65' (fed with 1/2" hardline)
73, N0AN *Hasan*
On Sun, Feb 16, 2020 at 6:09 AM Jackie Dander via AMSAT-BB < [email protected]> wrote:
I built the combination dual band 2meter/70cm antenna found at WA5VJB's webpages. I chose the 5 elements on UHF forward and 2 elements on VHF rear. All elements are in the same plane. I now read elsewhere that in-same-plane uhf/vhf elements can interfere with each other. I visited the Arrow website and see their LEO antennas are opposing for uhf/vhf. My question is if i made a mistake building the uni-plane version? Why did WA5VJB has such success? _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb