User manual SENNHEISER RI 150 DATASHEET

[. . . ] RI 150 IR Audio Transmission Technology | Receivers General Description The RI 150 is an extremely lightweight wideband stethoset receiver which uses the carrier frequency 2. 3 MHz, thus offering excellent transmission reliability. It features an easy-to-operate on/off/volume control and is powered by the environmentally friendly BA 151 rechargeable NiMH accupack delivered with the receiver. [. . . ] A built-in squelch avoids loud hiss when the signal from the IR radiators is too weak, for example when a receiver is used outside the radiator coverage area. The RI 150 is an elegantly shaped receiver which is very easy to use: the only control the wearer has to operate in order to hear the transmitted signals is a combined on/off/volume control with a small position indicator for reading off the volume. The audiology variant RI 250 has additionally been fitted with a balance control to compensate for hearing differences between the ears. The audiology version has a higher SPL and comes with strips of adhesive tape for covering the apertures on the earpieces. By sealing them, low-frequency response can be altered: the more apertures are covered, the more the lower frequencies are attenuated. Thus, speech intelligibility is increased without increasing the volume. Due to its balance control and the option of altering low-frequency response, the RI 250 can be ideally matched to the ears of its user. At the bottom, the variant RI 250 J is fitted with an audio ouput socket (3. 5 mm jack). Users can wear the stethoset receiver as usual, or they can put the stethoset arms around their neck and connect a pair of headphones to the receiver output socket or have the sound transmitted to a suitable hearing aid via induction couplers or an induction neck loop. The RI 250 J also comes with strips of adhesive tape for altering the frequency response. The receivers are powered by the environmentally friendly BA 151 NiMH accupack. For domestic applications, the L 151-2 charger is the optimum choice: it is designed for two BA 151 accupacks and comes complete with mains unit. [. . . ] The recharging of the receivers is carried out automatically and takes 10 hours. Audio output socket of the RI 250 J Apertures for altering the frequency response Two IR receiving diodes (behind special plastic cover) Audio output, 3. 5 mm jack (RI 250 J only) On/off/volume control Inserted BA 151 accupack RI 150/RI 250/RI 250 J stethoset receiver Excellent ease of operation: The user has only to operate the on/off/volume control RI 250/RI 250 J: Altering the low-frequency response with the adhesive tape included with the unit Three cascaded L 151-10 charging units with NT 2013 (or NG 2013-UK) plug-in mains unit and receivers [. . . ]