AKG SR470 BD7 Wireless Receiver 500 to 530 MHz Space Diversity

AKG SR470 BD7: Band 7 Space-Diversity Receiver for the WMS470 System

The AKG SR470 is a professional analog UHF space-diversity wireless stationary receiver for the WMS470 system, supplied here in the Band 7 configuration covering 500.1 to 530.5 MHz. Its audio path runs 35 to 20,000 Hz with a 120 dB-A signal-to-noise ratio and less than 0.3 percent total harmonic distortion at 1 kHz, figures that put it well clear of the entry-level wireless most rooms start with. Radio performance is equally serious: microcontroller-controlled space diversity, 30.5 MHz of switching bandwidth subject to local regulations, RF sensitivity of 6 dB microvolt equal to -100 dBm, and two detachable antennas on 50 ohm BNC connectors. It is a receiver rather than a complete system, so it holds one half of a channel and pairs with an HT470 handheld or a PT470 bodypack ordered separately. For an integrator standardising a rack on one wireless platform, this is the half-rack box that everything else plugs into.

Band 7, 500.1 to 530.5 MHz, and Where It Sits in the Spectrum

Band 7 on this platform covers 500.1 to 530.5 MHz, and the receiver can move anywhere inside 30.5 MHz of switching bandwidth subject to the rules in force locally. That position in the spectrum is the practical reason many buyers choose Band 7 over the higher band: it sits well below the 600 MHz mark that spectrum regulators redrew when the upper UHF range was reallocated to mobile broadband, so a channel plan built here is not brushing against a restricted edge. Switching bandwidth is the width of spectrum the receiver can retune across without new hardware, and 30.5 MHz is enough room to walk a channel away from a newly arrived television transmitter or a neighbouring production. A theatre that re-coordinates for every visiting show, and a house of worship that has to work around whatever the town broadcasts, both benefit from having somewhere to move.

Microcontroller-Controlled Space Diversity

Diversity reception on this receiver is microcontroller-controlled, meaning a processor watches both antenna paths and decides which one to use rather than leaving the choice to a simple comparator. Radio energy in a room arrives by several routes at once after bouncing off walls, trusses and people, and where two copies of the same wave cancel the result is a null, a small dead pocket in which a single-antenna receiver loses the transmitter entirely; two spaced antennas almost never share a null, so a diversity receiver can always find a healthy path. Combined with 6 dB microvolt sensitivity, equal to -100 dBm, the receiver keeps a usable link long after a weaker front end would have started to crackle. A musical theatre performer crossing upstage behind scenery, or a preacher walking down a side aisle, stays present rather than flickering out for a word.

Enhanced Automatic Setup, Channel Preview and TV Channel Presets

Setup on the SR470 is built around an enhanced automatic routine with channel preview, backed by pre-coordinated television channel presets. Automatic setup asks the receiver to survey its band and report the channels it can hear nothing on, while channel preview lets an operator listen to a candidate channel before committing the system to it, which catches the interference that a bar-graph scan reports as clear; the pre-coordinated television channel presets go further, offering frequency groups that are already spaced so that several systems dropped into the same group will not intermodulate with each other. Infrared synchronisation then transfers the chosen frequency from the receiver to the transmitter, so nothing is typed in twice and no channel is left mismatched. For a corporate AV team dropping into an unfamiliar hotel ballroom every week, that sequence turns frequency coordination from a specialist skill into a repeatable checklist.

The Programmable Multicolor Display and Reading a Rack at a Glance

Front-panel information comes from a programmable multicolor backlight display whose warnings are colour-coded for transmitter battery status, audio peaks and received signal strength. Colour is doing real work here rather than decoration: a technician standing several feet from a rack cannot read small numerals but can see instantly which of eight receivers has turned from its normal colour, which is why a colour-coded warning finds a dying transmitter battery or a channel being overdriven far faster than a row of identical bar meters ever will. Because the display is programmable, the brightness and behaviour can be set to suit a dark theatre wing or a brightly lit rack room. In a busy show call, a stage manager or an A2 wants to know which channel needs attention, not to interrogate a menu, and that is exactly the question this display answers.

Outputs, Rack Integration and the Transmitters It Pairs With

Audio leaves the receiver on a balanced XLR connector switchable to -30 or 0 dBm and on an unbalanced 1/4 in (6.3 mm) TS jack with a maximum output of plus 9 dBu, and the chassis is a half-rack metal housing supplied with the RMU4000 rack mount kit. Those two output levels exist because a console microphone input and a line input want signals about 30 dB apart, and choosing the right one at the receiver keeps a channel out of the noise floor without the mixer having to rescue it; the two 50 ohm BNC antenna connectors are equally deliberate, because detachable antennas mean remote, directional or active antennas can be added when a rack ends up in a closet far from the room. Capacity runs to 16 simultaneous channels within one frequency band and up to 48 when several bands are combined, and the receiver runs on 12 V DC at 500 mA. Pairing is with an HT470 handheld or a PT470 bodypack in the same band, ordered separately, so the check that matters at the point of order is simply that the band designation matches the transmitter already in service.