User manual ASL INTERCOM PS 29

[. . . ] As an option, a XLR-6 headset connector can be fitted allowing the user to hear channel A at the left headset can and channel B at the right headset can. 2. 0 UNPACKING After unpacking the unit please inspect for any physical damage to the unit, and retain the shipping carton and relevant packing materials for use should the unit need returning. If any damage has occured, please notify your dealer imediately so that a written claim can be initiated. Please also refer to the guarantee section of this manual. The shipping carton contains the parts below: * * The PS 29 User manual If any are missing, contact your dealer. ASL has taken great care to ensure this product reaches you in flawless condition. 3. 0 INSTALLATION To connect the PS 29 onto the intercom system, use professional flexible microphone cable with 2 wires and 1 shield only. [. . . ] The operating area is between fully clockwise and minimum level. Follow this procedure for both channels. Adjusting the sidetone does not affect the level of your voice as it is heard by other stations. 9 BUZZER VOLUME trimmer This trimmer adjusts the volume of the internal buzzer. The buzzer will be activated if a CALL-button is pressed for longer than 2 seconds and the buzzers are not muted on the power supply. 7. 0 INTERNAL CONTROLS MIC GAIN The mic gain can be adjusted internally by a trimmer. Open the PS 29 by removing the four screws on the underside. The trimmer is located on the lower PCB board. To decrease mic gain turn counterclockwise. User Manual PS 29 / Issue 1 © 1994 ASL Intercom, Utrecht, Holland. 5 8. 0 CABLING For the PRO Series Intercom system the interconnecting cables are of the shielded two-conductor microphone cable type and the intercom line connectors are of the XLR-3 type. Audio and Call signals are on XLR pin 3, DC power is on XLR pin 2. XLR pin 1 is connected to the shield of the cable which functions as the common return for audio and power. Since the audio signal is transferred in an unbalanced way, certain rules have to be obeyed when installing the cables of an intercom network. This is to avoid earth loops and to minimize power loss and the possible effect of electromagnetic fields. These rules are: ¼ Use high quality (multipair) cable. For interconnecting user stations, power supplies and accessories in an ASL Intercom network, use high quality shielded two-conductor (minimum 2x 0. 30 mm2) microphone cable only. In case of a multi channel intercom network, use high quality microphone 'multipair' cable only, each pair consisting of two conductors (minimum 2x 0. 15 mm2) with separate shield. Multipair cable should also have an overall shield. Use flexible single and multipair microphone cable instead of cable with solid cores, especially when the cable is subjected to bending during operation or installation. The screen of each separate microphone cable and/or the screen of each single pair in a multipair cable, should be connected to pin 1 of each XLR-3 connector. Do not connect this cable screen to the metal housing of the connector or to metal wall boxes (outlets). Cable trunks, connection boxes and overall multipair cable screen to clean earth. Metal cable trunks, metal connection boxes and overall multipair cable screen should be interconnected and, at one point (the 'central earthing point') in the intercom network only, be connected to a clean earth or a safety earth. Keep metal connection boxes and cable trunks isolated from other metal parts. Metal housings for intercom cables and connectors should be mounted in such a way that they are isolated from other metal cable and connector housings and from any other metal construction parts. Keep cables parallel as much as possible. [. . . ] This principle has three advantages: - the use of a single audio line allows several stations to talk and listen simultaneously. - due to the high bridging impedance offered by each station, the number of stations 'on line' has no influence on the level of the communications signal. - power and audio to the intercom stations use the same cable. The Call signal is also sent as a current on the audio line. [. . . ]