MODEL SPK300L TW INTERCOM SYSTEM PORTABLE SPEAKER USER STATION 9300-3505-00 Rev G 09/2007
PROPRIETARY NOTICE RETURN SHIPPING INSTRUCTIONS The product information and design disclosed herein were originated by and are the property of Telex Communications, Inc. Telex reserves all patent, proprietary design, manufacturing, reproduction, use and sales rights thereto, and to any article disclosed therein, except to the extent rights are expressly granted to others. Customer Service Department Telex Communications, Inc.
CHAPTER 1 Introduction DESCRIPTION The Model SPK300L, a Portable Speaker User Station, is a component used in the TW INTERCOM SYSTEM. Each User Station is a communications unit along a multi-unit conference bus. Figure 1, “TW System Concept Block Diagram,” on page ii, shows User Station interconnection, and User Station connection to the system power supply.
Introduction The Channel Selector Switch selects the channel on which the user will talk and listen. The headphone amplifier output drives the user's headphones. The Volume Control also feeds the speaker amplifier via the speaker switch and the speaker dim network. The User Station Voltage Regulator takes power from channel 1, regardless of the channel selector switch setting (exception: local power option units).
Specifications FIGURE 1. SPK300L Block Diagram Specifications OPERATING DISTANCES Audio Line Voltage 1 volt, peak (0 dBm voltage-equivalent) Average Speech Level Range -20 dBV to -10 dBV Absolute Maximum Speech Level 3 volts, peak (linear limit) Audio Line Impedance, Nominal 200 50 ohms, 75 Hz to 20 kHz System will continue to operate from 50 ohms to 300 ohms. Maximum DC limit 5,000 ft distance along cable, power supply to single station #22 gauge wire - DC voltage drop limitation.
Introduction Limiter Range 50 dB Carbon Mic Excitation Current 10 milliamps, nominal CURRENT SOURCE Transfer Ratio 5 milliamps/1.
CHAPTER 2 INSTALLATION MECHANICAL INSTALLATION The Model SPK300L Portable Speaker User Station is 4.0 inches (101.6 mm) high X 8.0 inches (203.2 mm) wide X 8.0 inches (203.2 mm) deep. Additional depth should be allowed for the rear panel XLR-type line connectors. When installing this unit, allow space for control access, cabling and servicing. Provide space for: cabling service loops, reaching XLR-type connector lock releases, and headset connector/cables.
INSTALLATION ELECTRICAL Power The SPK300L receives electrical power from either: (1) a system power supply (26 to 32 volts DC on line connector pins 2 (+) and 1 (com) (1 or two channel operation); or (2) a local power supply option (14 to 26 volts DC). A user station requires 18 to 33 volts to be a 10,000 ohm bridging impedance across the powering line, but the station can otherwise operate (as in the local power option) from 12 to 33 volts.
USER STATION CONNECTIONS Routing the TW Intercom System cables along the same ductways and pathways as power cabling can increase the noise and hum levels. Moisture / Contamination Protection When using equipment in the rain, always protect the equipment with plastic covers----also, make sure all cable connectors are lifted out of the mud or snow and protected with plastic bags. Water, mud and snow in connectors can cause considerable audible noise.
INSTALLATION 8
CHAPTER 3 OPERATION Operating Controls The table below lists the Model SPK300L operating controls. The reference numbers in the table correspond to the circled numbers in Figure 3-1. TABLE 1. Model SPK300L Operating Controls REF NO. NAME DESCRIPTION 1 Channel Select Switch Selects one of two channels (standard) or one of three channels (optional). The Call Light Option transmitter and receiver operate on the channel selected by this switch.
OPERATION 6 FIGURE 1. 2 1 4 7 3 & 5 SPK300L Reference View Adjust the Sidetone To adjust the SIDETONE control for speaker operation, do the following: 1. Turn ON the speaker switch. 2. Turn ON the microphone switch. 3. Set the VOLUME control to about 50% 4. Hum into the panel microphone and adjust the SIDETONE for minimum sound through the loudspeaker. To adjust the SIDETONE control for headset operation, do the following: 1. Turn OFF the speaker switch. 2. Turn ON the microphone switch.
Operating Controls 4. Wire PG, 4-pin plug (Calrad #30-453, RTS # 2013-0016-00) to the external supply: Pin 1 = common, Pin 2 = external supply +. 5. Plug P6 into J6 on the RMS300 or SPK300L back panel. NOTE: If using RTS local power option kit 9002-5541-00, the external supply will already be wired to P6. Obsolete products have been discontinued and are no longer available for purchase. 4 1 3 2 J6 Local Power (Back Panel) #22 AWG Wire Remove D26 CC 300 P.C. Board FIGURE 2. CC300 P.C.
OPERATION 12
CHAPTER 4 DRAWINGS 13
DRAWINGS Model SPK300L Number TitleS D2712 Schematic Diagram, CC300, page 1 of 3 SD2712 Schematic Diagram, CC300, page 2 of 3 SD2712 Schematic Diagram, CC300, page 3 of 3 Wiring for External Microphones SD3585 Servicing Diagram, Model RMS300/SPK300L, WD2712 Wiring Diagram, pg. 1 of 7 SPK/RMS300 Standard -L Option and Local Power Option WD2712 Wiring Diagram, pg. 2 of 7 SPK/RMS300 3CH and 3CH-L Options WD2712 Wiring Diagram, pg. 3 of 7 SPK/RMS300-DL WD2712 Wiring Diagram, pg.
