IR transmitter main unit STC-641,STC-661 High security Be suitable be used in all kinds of meeting Light immunity Easy to install, save the project cost Frequency synthesis: digital PLL Smart design With six independent outputs for sound recording Transmits up to six audio channels to different carrier frequencies It features built-in IR test diodes for testing of receivers LED audio level indicators 19" rack mountable Modulation: FM 6 individual frequencies output socket can be connected with infrared and wireless language division system IR transmitter unit STC-642,STC-662 Maximum area of coverage: 40m(25w)/20m(15w) Radiate and distribute up to many channels of audio signal throughout the conference venue Easy to be chained together to expand coverage, with15 watt and 25 watt available to suit venues of different sizes Can be mounted on the ceiling and wall or on optional floor and tabletop stand Transmit signal adjust switch IR receiver unit STC-643,STC-663 Equipped with lightweight single earphone for relieving ear pressure and for better hygiene 6 channels of languages can be selected Each channel works independently Volume level can be adjusted through a volume control for comfortable listening. Easy to be used and be took Smart design AAA batteries or two rechargeable batteries, can work for 40 hours The receiver can be hung or be put into the pocket Any number of receivers can be used in an installation With the wireless pocket receivers, the delegates can enjoy complete freedom to move around. IR interpreter STC-666F Digitally-controlled Comfort-fit headband and closed-ear design Automatic acoustic feedback prevention An automatic channel interlocking function prevents them from using the same output channel. COUGH CUT for muting microphone SLOW indication to floor speaker Auto relay function enables them to work from an active channel other than the floor, and to provide relay interpretation in case they are unfamiliar with the floor language and unable to interpret it Can use with the infrared language division system One interpretation unit can be used for two interpreters Interpreters may quickly switch between the floor language and the channel set IR transmitter main unitIR receiverTransmitter unitFMmodulationFM/ PLLFM/PLL/Sub-carrier-PPM spectrum 2.0 6.0MHz2.0 6.0MHz/Audio frequency 100 14KHz100 14KHz/T.H.D <0.5%<1%/S/N Radio >70dB>55dB/Frequency //2.0 6.0 MHzOutput impedance //50OhmInput frequency //100-2000MvRF output level 700Mv/110V/220VACRF output impedance 50Ohm/Input impedance 18KOhm/Maximum input level 7.5V/AGC range 30dB/50%/100%Frequency input/output BNC socket×2//PowerRequirement AC110-2402.3V-3.6V/PowerConsumption 40W50mW/Dimension //211×450×82mmWeight //3.8KgIndicator Level indicator //Frequency stability 10PPM10PPM