AKG RA4000 EW Passive Omnidirectional UHF Antenna 470 to 952 MHz

AKG RA4000 EW: A Passive Omnidirectional Antenna That Needs Nothing From the Rack

The AKG RA4000 EW is a passive omnidirectional wide-band UHF antenna covering 470 to 952 MHz with 1 dBi of gain and a 360 degree covering angle, terminating in a BNC female output at 50 ohms. Being passive is the defining characteristic: there is no amplifier inside, no current drawn and no DC feed required up the coaxial cable, so the antenna works with any receiver or splitter that presents a 50 ohm BNC connection. AKG rates it for cable runs up to 33 ft (10 m), and supplies a universal stand adapter for 3/8 in or 5/8 in floor stand threads in the box, with a water-resistant housing that suits indoor and outdoor positions alike. It works equally as a receiving antenna for wireless microphones or a transmitting antenna for in-ear monitoring. Getting an antenna out of a rack and into line of sight is the single largest improvement most wireless systems can make.

Passive Design, No DC Feed and the 33 ft Cable Limit

Containing no amplifier is what makes this antenna simple and also what defines its limit, which AKG states plainly as cable runs up to 33 ft (10 m). Coaxial cable is lossy at UHF and every foot between antenna and receiver removes signal that no downstream device can recover, so a passive antenna only makes sense while the run is short enough that the loss stays small; beyond that the active version of the same antenna, with its integrated booster, or an in-line booster becomes the correct choice. What a passive antenna gives in exchange is total independence from the powering arrangement, since it does not care whether the receiver or splitter it connects to can send DC up the coax, and there is nothing inside to fail or to overload a front end. Portable racks that set up and strike daily benefit most from that simplicity, because one fewer powered device in the chain is one fewer thing to diagnose in a car park at midnight.

Omnidirectional Coverage and Where to Position It

Collecting signal equally over a 360 degree covering angle is what an omnidirectional antenna does, and it is the right pattern whenever transmitters are moving around the antenna rather than staying in one arc. Directional antennas concentrate their sensitivity in one direction and reject what arrives from behind, which is valuable in a large venue with a defined stage, but on a small stage where performers walk behind the rack or in a room where presenters move freely an omnidirectional pattern removes the null that a directional antenna would create; the practical consequence is that positioning becomes about line of sight rather than about aiming. Height helps far more than gain here, so getting the antenna above head level and away from metalwork, bodies and lighting fixtures does most of the work. Using the supplied stand adapter on a microphone stand at the side of a stage is the fastest way to achieve that, and it is how most of these are actually deployed.

Transmit Duty, In-Ear Monitoring and Weather Resistance

Serving as a transmitting antenna is explicitly part of this antenna's specification, which puts it on the output side of an in-ear monitoring system as readily as on the input side of a microphone receiver. In-ear monitoring reverses the usual geometry, with one transmitter in the rack radiating to receivers worn by performers, and the same properties that make an omnidirectional antenna good at collecting a moving transmitter make it good at reaching moving receivers; a single part number therefore covers both jobs in a rack that runs microphones and monitors together. Water resistance extends that flexibility outdoors, so the antenna can live on a truss, in a ceiling void, above a proscenium or on a covered stage without additional protection. Houses of worship, small theatres, conference rooms and mobile production racks all use it in exactly those positions, and in every case the deciding factor is that a short cable run and a clear line of sight beat a longer run to a more sophisticated antenna.