AKG HT4500 BD8 Reference Wireless Handheld Transmitter 570-600 MHz

AKG HT4500 BD8: Reference Handheld Transmitter Body for Band 8

The AKG HT4500 BD8 is a reference analog UHF wireless handheld transmitter tuned to frequency Band 8, 570.1 to 600.5 MHz, offering up to 1,200 selectable carrier frequencies across a 30 MHz band at up to 50 mW of RF output. It is a transmitter body designed around interchangeable screw-on WL1 series capsule heads, which are ordered separately, so the same handheld can carry a dynamic or a condenser element depending on the performer using it. A backlit display with a jog switch handles menu navigation, while a pilot tone sends the receiver continuous status data including the mute switch position and remaining battery life. Two AA-size dry cells run it for up to 15 hours, or the optional BP4000 rechargeable pack for 12, charged through integrated contacts. It is the handheld channel of a platform that scales to 70 simultaneous systems.

Body and Head as Separate Purchases, and Why That Helps

Separating the transmitter body from the microphone head is the defining design decision of this platform, and it changes how a production buys and deploys handhelds. Six microphone elements are offered for the body, and the screw-on WL1 heads include the D5 WL1 supercardioid dynamic, the D7 WL1 reference dynamic, the C5 WL1 condenser and the C535 WL1 reference condenser, each of which threads onto the same transmitter and turns it into a different microphone; the radio, the battery, the display and the charging arrangement stay identical while the acoustic character changes completely. Practically, that means a festival can hand a headline vocalist their preferred capsule on a body already coordinated into the rack, and an inventory can hold ten bodies and fifteen heads instead of twenty-five complete microphones. Worth stating clearly at the point of order: this part number is the body, so a capsule head must be selected alongside it unless one is already in service.

Band 8 and the Coordination Check Before Deploying

Band 8 covers 570.1 to 600.5 MHz, which places its upper edge exactly at the boundary that regulators in the United States redrew during the 600 MHz spectrum repack. Spectrum at and above 600 MHz was reallocated to mobile broadband, and wireless microphone operation in that reallocated range is now restricted, so although the large majority of Band 8 sits below the boundary, the top of the band brushes against it and the usable portion depends on current local regulations. Confirm that Band 8 operation is permitted at your location and coordinate carriers below the restricted range before the rig is committed, and apply the same check to the SR4500 receiver in the rack since it occupies the same band. With 1,200 selectable frequencies spread across 30 MHz there is normally plenty of room to place every channel legally; the point is to verify rather than assume.

Frequency Density and the 70-Channel Platform

Up to 1,200 carrier frequencies inside a 30 MHz band is the specification that makes high channel counts possible, because coordination is fundamentally a problem of having enough places to put things. Two wireless channels cannot simply be placed at any two frequencies, since their transmitters generate intermodulation products that land at predictable arithmetic combinations of the carriers and can appear as interference on a third channel, and the more finely a band can be subdivided the more easily a coordinator can find a set of carriers whose products all fall in unused gaps. Across the WMS4500 platform that arithmetic supports up to 70 channels running simultaneously, which is festival and large-scale touring territory rather than club work. Broadcast productions, awards ceremonies and arena tours are the users who need that headroom, and 50 mW of RF output gives each of those channels the margin to survive bodies, walls and lighting rigs between transmitter and antenna.

Reading the Transmitter and What the Pilot Tone Reports

Menu navigation is handled by a jog switch working with a backlit display, and the pilot tone does something considerably more useful than merely keying the receiver's squelch. A pilot tone in its simplest form is an inaudible signal that tells a receiver a genuine transmitter is present so it can mute when the transmitter leaves range instead of passing RF noise to the PA; here the tone additionally carries transmitter status data, so the receiver knows the position of the mute switch and how much battery life remains without anyone walking on stage to look. For a monitor engineer or an RF technician watching a rack of receivers, that turns battery management from a scheduled guess into observed fact, and a mute left on by a presenter becomes visible from the rack rather than mysterious. Backlighting matters for the same reason it matters on any stage device, which is that a panel nobody can read is a panel nobody uses.

Power, Charging and Where the HT4500 Is Deployed

Running on two AA-size dry cells for up to 15 hours means a single set of common batteries covers even a very long production day, and the optional BP4000 rechargeable pack substitutes 12 hours of runtime for a repeatable overnight routine. Integrated charging contacts on the body allow that pack to be recharged with the transmitter closed in the CU4000 charging unit, so a fleet goes on charge in one gesture and no loose cells are handled or lost in the dark. Deployments follow the platform: large-scale touring and festival stages, theatres and arenas where one body serves several vocalists through different capsule heads, broadcast and awards productions that rely on status telemetry, permanent multichannel racks in large houses of worship, and rental inventories that deliberately stock bodies and heads as separate line items. Anyone buying this SKU is almost always matching a Band 8 receiver already installed and working.