Sennheiser EM 550 G2 manual Diversity reception

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EM_550_G2.book Seite 67 Donnerstag, 27. November 2003 1:33 13

Diversity reception

The two receivers of the EM 550 G2 operate on the “true diversity” principle:

A receiving antenna receives not only the electromagnetic waves which reach it by a direct path, but also the reflections of these waves which are created in the room by walls, windows, ceilings and fittings. When these waves are superimposed, destructive interference occurs, which can also be called “field strength gaps”. Repositioning the receiving antenna can bring a solution. With mobile transmitters, however (which all radiomicrophones are), the “field strength gap” will then occur with a different transmitter position. These “field strength gaps” can only be eliminated with true diversity receivers.

In true diversity, instead of one antenna and one receiver there are now two antennas and two receiver sections. The antennas are spatially separated. By means of a comparison circuit, the receiver section with the strongest RF signal is always switched to the common AF output. The risk of the occurrence of “field strength gaps” in both antennas at the same time is virtually nonexistant.

The receiver display panel shows the active diversity section (I or II) .

Control signal

Receiver section I

Electronic

switch-over of

AF signal

Control signal

Receiver section II

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Contents EM550 Thank you for choosing Sennheiser Contents Channel bank system EM 550 G2 twin receiverDelivery includes Safety instructionsAreas of application Overview of operating controls Indications and displays of the receivers Indications and displaysRemote displays of an ew 500 G2 transmitter Modulation display Mute displayMounting the receiver feet Connecting the antennasConnecting and mounting remote antennas Preparing the receiver for useDaisy-chaining up to eight twin receivers Connecting the mains cableEssential notes on mounting remote antennas Mounting the antennas Connecting the amplifier/mixing consoleService interfaces Mounting the twin receiver into a 19 rackEM550G2.book Seite 49 Donnerstag, 27. November 2003 133 Activating/deactivating the lock mode Using the twin receiverSwitching the twin receiver on/off Connecting the headphones/adjusting the volumeButtons Operating menuOverview of menus Working with the operating menu Menu Bank MenuSET Menu Reset Tune Adjustment tips for the operating menuBank ChannelStarting the scan Scanning the channel banks for free channelsScan Displaying a list of all free channelsAF Out Adjusting the audio output levelAdjusting the squelch threshold Multi-channel operationSoundcheck Doing the soundcheckName Selecting the standard displayDisplay Entering a namePilot Loading the factory-preset default settingsReset Activating/deactivating the pilot tone evaluationExiting the operating menu Using the equalizerAdjusting the contrast of the graphic display EqualizerError checklist TroubleshootingFor multi-channel operation Care and maintenanceRecommendations and tips For optimum receptionAdditional information Wireless transmission systemsHDX noise reduction Pilot tone squelch SquelchField strength-dependent squelch Diversity reception Specifications Connector assignment AccessoriesEM550G2.book Seite 212 Donnerstag, 27. November 2003 133