When the VHF and UHF are collinear and in the same electric plane, with the UHF array in front of the VHF array, the interference is hardly noticeable as long as the lower frequency is NOT transmitting. So, it works very well for sats that have UHF uplink and VHF downlink. However, experience has shown that a VHF uplink severely affects the UHF downlink.
Having them at 90 degrees to each other on the same boom is a real-world compromise - see beginner's article in AMSAT journals. Keeping them at least 1/2 wavelength side by side apart (like a H or U) works quite well for both V/U and U/V modes.
Having tried several arrangements, I have settled on the side by side arrangement with shorter arrays - it minimizes interference, helps reduce overall weight, while providing sufficient gain. Also dismantles quickly for easy carry.
On Wednesday, January 2, 2019, 12:50:14 PM PST, Douglas B Tabor via AMSAT-BB [email protected] wrote:
Many thanks to all for the information and observations. Much appreciated and will give me something to chew on for a bit.
This is a great community that we have at AMSAT-BB.
73 and HNY,
Doug, N6UA _______________________________________________ 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: http://www.amsat.org/mailman/listinfo/amsat-bb