AKG SR470 BD8 Wireless Receiver 570 to 600 MHz Space Diversity

AKG SR470 BD8: Band 8 Receiver for High-Count WMS470 Racks

The AKG SR470 is a professional analog UHF space-diversity wireless stationary receiver for the WMS470 system, supplied here in the Band 8 configuration covering 570.1 to 600.5 MHz. Band 8 is the higher of the two bands this receiver is offered in, and it exists so that a venue whose lower band is already crowded has somewhere else to put a channel, or so that a large rack can combine bands and reach a much higher channel count. Electrically it is the same serious receiver as its band sibling: 35 to 20,000 Hz audio bandwidth, a 120 dB-A signal-to-noise ratio, less than 0.3 percent total harmonic distortion at 1 kHz, 30.5 MHz of switching bandwidth subject to local regulations, and RF sensitivity of 6 dB microvolt equal to -100 dBm. Because the top of this band meets a regulatory boundary, it is also the configuration that demands the most homework before it goes into service.

Band 8, 570.1 to 600.5 MHz, and Verifying Before Deployment

Coverage on this configuration runs from 570.1 to 600.5 MHz, which means the upper edge of the band reaches the 600 MHz line that spectrum authorities in the United States redrew when that part of UHF was reallocated to mobile broadband. Verifying the plan is therefore part of commissioning rather than an afterthought: check the band designation printed on the receiver and on every transmitter that will work with it, confirm which frequencies inside the band remain permitted where the system will operate, and document the resulting channel list so a future technician inherits a plan rather than a guess. This is a coordination and legality check, not a comment on the hardware, and it applies equally to a permanent install and to a touring rack that crosses regulatory areas. A theatre commissioning a new rack, a university auditing an estate of installed systems, and a rental house preparing a rig for a regional tour all need the same short paper trail.

Pilot-Tone Code Squelch and What a -100 dBm Front End Buys

Squelch on this receiver is pilot-tone coded, which means the transmitter sends a continuous inaudible tone alongside the audio and the receiver refuses to unmute unless it hears that specific tone. Ordinary level-based squelch simply asks whether a signal is strong enough, so a dimmer buzz, a motor, or a carrier from an unrelated system can be loud enough to open the gate and arrive in the loudspeakers as a burst of noise; coded squelch asks a harder question and cannot be fooled by energy alone, and the same tone doubles as a data path that carries transmitter battery status back to the display. Sensitivity of 6 dB microvolt, equal to -100 dBm, works alongside it by keeping genuinely weak signals usable rather than noisy. In a broadcast studio full of switching supplies, or an arena with LED walls behind the stage, those two behaviours together are the difference between a clean channel and one nobody trusts.

Environment Scan and Rehearsal: Finding Trouble Before the Audience Does

Two setup tools on this receiver do work that a simple frequency scan cannot: an environment scan and a rehearsal function. An environment scan sweeps the band and records what is present across it, giving a picture of the local radio landscape rather than a yes-or-no answer about one channel, while the rehearsal function watches a chosen channel over a period of time and logs the dropouts, mutes and level events it sees, so a problem that only appears when a room fills up is caught and attributed instead of being blamed on the microphone. Channel preview and pre-coordinated television channel presets round the toolset out, the presets offering frequency groups already spaced so that several systems dropped into the same group will not intermodulate. An A2 who runs a rehearsal pass during a sound check arrives at doors with evidence, which is a very different position from hoping.

Antenna Infrastructure on Two 50 Ohm BNC Connectors

Antenna connection is made on two BNC female sockets at 50 ohms, with detachable antennas supplied, and that single design decision is what lets the receiver serve a real installation. A rack in a back-of-house closet or a basement machine room is often nowhere near the space the performers occupy, and antennas mounted on the box in that position will hear walls rather than transmitters; because these connectors are standard and the antennas come off, the same receiver can instead be fed from a remote antenna in the room, from a directional antenna aimed at a stage, or from an antenna power splitter distributing one antenna pair across several receivers. Microcontroller-controlled space diversity then uses both paths, comparing them continuously so that a null on one is ridden out on the other. Houses of worship with the rack down a corridor, theatres with antennas above the proscenium, and conference centres feeding many receivers from one pair all depend on exactly this arrangement.

Capacity, Powering and Buying a Receiver on Its Own

Channel capacity reaches 16 simultaneous systems within one frequency band and as many as 48 when several bands are combined, which is the reason Band 8 hardware appears in racks that already contain the lower band. Audio leaves on a balanced XLR switchable to -30 or 0 dBm and on an unbalanced 1/4 in (6.3 mm) TS jack reaching plus 9 dBu, the chassis is a half-rack metal housing supplied with the RMU4000 rack mount kit, and the receiver runs on 12 V DC at 500 mA. Almost nobody buys a receiver as a first purchase, so the realistic reasons for this part number are a failed receiver in an installed Band 8 channel, a rack that already holds matching-band HT470 or PT470 transmitters and needs another channel, or spare stock held against a show-day failure. Matching the band designation on the receiver to the transmitters already owned is the one check that has to happen before the order is placed, and on this band it sits alongside the spectrum verification above.