Chris, The best answer to your question is: "It depends."
First, it depends on where the repeater will be in relation to the desired coverage area. If it's more or less centrally located, then an omnidirectional antenna is the obvious choice. However, if the repeater is at the edge of the coverage area, then the choices will be an offset antenna or perhaps a corner reflector or a Yagi. A directional antenna high on a hilltop can be physically tilted down to enhance coverage. Second, it depends on the climate and the amount of wind and lightning expected at the antenna site. Third, it depends on the amount of gain needed to perform satisfactorily. Remember that antenna gain is nothing more than moving the response of the antenna from where is does no good (like up in the air) to where it does some good. If you install a super-high gain antenna on a hilltop site, you may find that its pattern goes over the heads of close-in stations. Remember, too, that omni antennas with a downtilt pattern are custom-made for your exact frequency, are very costly, and have a rather erratic response pattern. Caveat Emptor! Fourth, it depends on whether you are going to use one antenna in duplex mode, or use separate antennas for TX and RX. Some antenna designs do not "duplex well" and should be avoided. The overall range of most radio systems is determined by the talk-back range, that is, the field radios can hear the base station at greater distances than the base can hear the field radios. The base (or repeater) receive antenna is at the top of the tower, and the transmit antenna is lower. The duplexer is split, with the two sides connected directly to their respective antennas. At a commercial site, a receive multicoupler allows one antenna to serve many receivers. My personal choices for 2m: Celwave PD220-7 Super StationMaster (omni) and Sinclair SRL-222 (offset). My personal choices for 70cm: Celwave PD1150 (omni) and Decibel Products DB404 (omni or elliptical). 73, Eric Lemmon WB6FLY Chris wrote: > > What would be the best commercial antenna to use as a repeater antenna?... Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
