The GP-9 is the highest gain, dualband fixed station antenna available from COMET. If you desire the absolute maximum coverage area, this is the antenna to choose. The radiation pattern is directed to the horizon omni-directionally around the antenna.
However, keep in mind that a high-gain antenna pattern has narrow elevation angle. In mountainous areas the pattern may not reach valley floors or mountain tops. If you need to cover areas around the antenna that are a few thousand feet above or below the antenna elevation, the GP-6 may be a better choice due to the wider radiation angle of a lower gain antenna.
2M: 8.5dBi 5/8 wave x 3 440MHz: 11.9dBi 5/8 wave x 8 VSWR: 1.5:1 or less Max Power: 200 watts SSB/100W FM Length: 16' 9? Weight: 5 lb 11 oz Mounting to Mast Size: 1.25? Connector: SO-239 (GP-9) Max wind survival: 92MPH Construction: Heavy-duty fiberglass, 3 sections. A short threaded sleave screws onto the bottom of the antenna providing the antenna/coax connection protection from the elements. Although hundreds are in use in repeater systems, it was not designed for mountain-top installation where extremely high winds, ice and other extreme conditions exist.
It performs best in low to mid elevation installations where the high gain radiation pattern is most effective. Mount pipe acts as shroud to protect the antenna/coax connection from the elements. Unique "split-thread" lock bolt is supplied to attach the antenna to the mount pipe, the threads compress when installed to keep the bolt from backing out.