Kathrein/Scala's CL-1469B is a large log-periodic antenna made to be outdoors permanently.

Perhaps you want to avoid a directional wireless mic antenna — not a bad idea, especially if the venue isn't really that big. Marti makes a series of verticals that mount to a mic stand — such as the PAV450 (covers up to 480MHz). Even this antenna develops 3dB of gain over a dipole.

Lectrosonics ALP Series including the popular ALP620.

Any RF system that you design and assemble should make use of an antenna optimal for the job. Often times most of the effort placed in an RF system design considers only the gear that lives in the racks; but with any RF system, it's crucial to pay attention to the mundane details: antenna types, connector types, coax specifications. These items make up a crucial part of any radio station's infrastructure, and if they are neglected, the system's performance is bound to be degraded at some point in time, whether from day one or at some point in the future.

Doug Irwin is the chief engineer of WKTU-FM, New York City.