Phonak CAMPUS User Manual Design Specification

Phonak Inc Design Specification

Manuel

communicationsystemsDevelopmentTechnical NoteManuelCampus S FM Transmitter (TX2S)US VersionDoc.:Vers.:Page:Date:TN010906.docV11 of 506.09.01Distribution: Montena EMC SA, CH-1728 Rossens, Mr Manfred PortmanPath: Marquis:> D:/data/phonak/T_memos/Englisch/TN010906.docName Date VisumProduced by F. Marquis 06.09.01 FMaApproved F. Marquis 06.09.01 FMaReleased F. Marquis 06.09.01 FMaManuelCampus S FM Transmitter (TX2S)History:Version Date Modifications PagesV1.0 06.09.01 New document all
communicationsystemsDevelopmentTechnical NoteManuelCampus S FM Transmitter (TX2S)US VersionDoc.:Vers.:Page:Date:TN010906.docV12 of 506.09.01BackgroundHearing impaired persons use hearing aids (HA), which are electroacoustic amplifiers including a microphoneand an earphone and having frequency response and dynamic characteristics specific to each hearing loss.BTE (Behind-The-Ear) hearing aids have the possibility to be connected to an external microphone, bymeans of electrical contacts placed on the bottom of the apparatus.A wireless solution for a remote microphone still exists: an FM radio receiver is connected to the HA, via theelectrical contact system for the external microphone. This FM radio receiver can be either :• In form of a little box, self powered by its own battery, and connected to the contact system by acable (for example Microvox R),or• A new system, fully miniaturised (Phonak Microlink), having the form of a piece of sugar, poweredby the hearing aid battery, an clipped on the bottom of the BTE-HA.A previous FM transmitter (Microvox TX2) is still in use for application in schools. The microphone isconnected with a cable to the small transmitter having the form of a little box. The transmitter is fixed to theclothes by a clip and the microphone by a small cord around the neck or a needle to the shirt.The Campus S (TX2S) is a more convenient remote microphone for hearing impaired persons. Campus Shas an integrated synthesizer which allows to change the frequency of the transmitting channel.TX2S is the development name of Campus S.Product descriptionThe Phonak Campus S is a FM transmitter (channel bandwidth of 25 kHz) for FM receivers, as the PhonakMicroLink or MicroVox, connected to hearing aid instruments. Its frequency for north america is from 216 to217MHz.The Campus S is equipped with 2 audio inputs:• Microphone-input for speech transmission (teacher)• Audio-input for external audio source (CD-player, radio, ...)The microphone can be switched as omnidirectional or directional.The Campus S has 2 modes of operation: off and active (transmitting). The status of the Campus S isindicated with the LCD display. When in off sate, the LCD display is blank. When transmitting, the Channelnumber is indicated on the LCD display.It can manually be switched on and off.The Audio-input adds the left and right channels of a stereo signal to generate a mono signal.The Campus S is powered by a prismatic NimH accumulator. A DC power supply (wallcharger) is used tocharge the accumulator. The Campus S is protected against polarity inversion and false voltage (too high orAC).The microphone cable is used as transmitter antenna.
communicationsystemsDevelopmentTechnical NoteManuelCampus S FM Transmitter (TX2S)US VersionDoc.:Vers.:Page:Date:TN010906.docV13 of 506.09.01Operating descriptionBefore starting, charge the accumulator of the Campus S during at least 12 hours. To do this, connect theplug of the Wall-Charger to the DC input shown on figure 1. The DC input voltage must be between 3VDCand 6 VDC.fig. 1 Campus S, audio and DC input1. Switching ON/OFFTo switch the Campus S ON, press during 1 second on the "ON/OFF" button. Then the channel number willbe displayed. The accumulator charge status is displayed.The Campus S is transmitting on the displayed channel.fig. 2 LCD and buttonsTo switch the Campus S OFF, press during 1 second on the "ON/OFF" button. The LCD display will becomeblank. The Campus S is in OFF state and is no more sending.
communicationsystemsDevelopmentTechnical NoteManuelCampus S FM Transmitter (TX2S)US VersionDoc.:Vers.:Page:Date:TN010906.docV14 of 506.09.012. Channel changeTo change the transmitting channel of the Campus S, press button "channel UP" or "channel DOWN" shownon fig. 3. Then the new channel number will be displayed and the Campus S is transmitting on the newchannel. "Channel UP" will increment to the next available channel and "channel DOWN" will decrement tothe next available channel. There are 23 channels programmed in the Campus S (see list in para 6.fig. 3 LCD and buttons3. Remote Control functionBy pushing the "Remote Control" button, the Campus S will inductively send a command to synchronizefuture receivers to the same frequency.4. External audio sourceAn external audio source (CD player, Radio, ...) can be connected to the Campus S via the audio input Jack(3.5mm). The audio level will be adapted with an AGC circuit (Automatic Gain Control). The signal will bemixed with the signal of the MM8 microphone. The microphone can be switched OFF.fig. 4 Campus S, audio and DC inputchannel UPchannel DOWNRemote ControlAudio Input
communicationsystemsDevelopmentTechnical NoteManuelCampus S FM Transmitter (TX2S)US VersionDoc.:Vers.:Page:Date:TN010906.docV15 of 506.09.015 MM8 microphoneThe MM8 microphone can be set in 3 different modes by rotation of the upper part of the microphone.In fig. 5, the MM8 microphone is set in "OFF" position. In this case, only the external audio signal will betransmitted.In fig. 6, the MM8 microphone is set in "OMNI" position. In this case, the microphone has an omni-directionalcharacteristicIn fig. 7, the MM8 microphone is set in "DIR" position. In this case, the microphone has an directionalcharacteristic fig. 5 Position "OFF" fig. 6 Position "OMNI" fig. 7 Position "DIR"6 Frequency list of the 23 channelsPhonak Channel Frequency [MHz]N01 216.0125N02 216.0375N04 216.0875N05 216.1125N08 216.1875N09 216.2125N12 216.2875N13 216.3125N16 216.3875N17 216.4125N18 216.4375N61 216.5125N62 216.5375N64 216.5875N65 216.6125N68 216.6875N69 216.7125N72 216.7875N73 216.8125N76 216.8875N77 216.9125N79 216.9625N80 216.9875

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