Model 450 Series II User Guide WIRING CONNECTIONS Refer to Figure 1 and Table 1 below. For unbalanced operation, the GREEN wire is connected to the audio input, the WHITE wire is connected to the audio ground, and the SHIELD is connected to chassis ground. In some cases, audio ground and chassis ground will be the same. For balanced operation, the GREEN wire is connected to the positive audio input, the WHITE wire is connected to the negative audio input, and the SHIELD is connected to chassis ground. IMPEDANCE SWITCH GREEN The Shure Model 450 Series II is a high output dynamic microphone designed for paging and dispatching applications. This extremely rugged microphone features an omnidirectional pickup pattern and a frequency response tailored for optimum speech intelligibility. It also includes an impedance selection switch and a locking press-to-talk switch. The press-to-talk switch can be converted to a monitor/transmit switch with the Shure RK199S Split-Bar Conversion Kit. Dual impedance Locking press-to-talk switch Rugged ARMO-DUR base and case Adjustable height Optional monitor/transmit switch conversion kit PRESS-TO-TALK SWITCH OPERATION To operate the control bar as a press-to-talk switch, simply hold it down and begin speaking. When you are finished speaking, release the control bar. To lock the control bar in the "on" position, press it down and pull it forward. To unlock the control bar, push it back and release it. IMPEDANCE SELECTION To select high or low impedance, move the impedance selection switch, located under the microphone base, to either the HIGH or LO position. The switch is factory pre-set to LO. Shure recommends the low impedance setting if long lengths of cable are used, or if severe hum is encountered. Use Shure A95 Line Matching Transformers to match a low impedance (300 ) microphone line to a high impedance amplifier input. 2001, Shure Incorporated 27B2917 (AC) 3 BLACK RED GREEN WHITE WHITE BLACK SHIELD ORANGE RED WIRING DIAGRAM FIGURE 1 Table 1. Typical Cable-to-Connector Wiring INPUT TYPE Features * * * * * 1 2 HI GREEN LO SHURE MODEL 450 SERIES II PAGING AND DISPATCHING MICROPHONE PRESS-TO-TALK SWITCH YELLOW UNBALANCED BALANCED WIRE COLOR FUNCTION XLR CONNECTOR 1/4 IN. PHONE JACK GREEN AUDIO PIN 2 TIP WHITE AUDIO GROUND PIN 3 SLEEVE SHIELD CHASSIS GROUND PIN 1 SLEEVE GREEN AUDIO + PIN 2 TIP WHITE AUDIO - PIN 3 RING SHIELD CHASSIS GROUND PIN 1 SLEEVE NOTE: The RED and BLACK leads are not part of the audio circuit. These wires provide a contact closure when the pressto-talk switch is depressed. This closure may be used to control an external relay or a transmit/receive circuit. CHANGING PTT CIRCUIT TO NORMALLY OPEN Using microphones in parallel requires a normally open microphone circuit. To modify the press-to-talk switch so that it provides a normally open circuit, proceed as follows: 1. Remove the screws, washers, and bottom plate from the microphone. 2. Unsolder the black, red, and white leads from terminals 2 and 3 of the press-to-talk switch (see Figure 1). Make sure these leads are still soldered together. If necessary, resolder them and insulate the connection. 3. Replace the bottom plate and secure it with the screws and washers removed in Step 1. Printed in Mexico TRANSMIT/MONITOR SWITCH CONVERSION KIT When the optional split-bar Transmit/Monitor Switch Conversion Kit is installed, the Monitor bar must be depressed before the Transmit switch can be depressed, requiring the operator to verify that the channel is open before transmitting. The Monitor bar can be locked in the "on" position. The Transmit bar is momentary and cannot be locked. NOTE: Transceiver wiring information must be obtained from the transceiver schematic and/or the manufacturer. Cable 2.1 m (7 ft.) four-conductor, two conductors shielded, non-detachable Case Two-tone gray ARMO-DUR SPECIFICATIONS Type Dynamic Frequency Response 200 to 5,000 Hz (see Figure 2) AAAAAAAAAAAAAAAA AAAAAAAAAAAAAA AAA A A A A A A A A A A A A A A A A A AAAAAAAAAAAAAAA A A A A A A A A A A AAAAAAAAAAAAAAA AAA AAAAA A A A A AA AAAAAAAAAAAAAA AAAAAAAAAAAAAAA A A A A A A A AAAAAA AAA A TYPICAL FREQUENCY RESPONSE FIGURE 2 Polar Pattern Omnidirectional Impedance (at 1,000 Hz) High Impedance: 30,000 Low Impedance: 225 Recommended Load Impedance High Impedance: 100,000 Low Impedance: 1,000 Output Level (at 1,000 Hz, Open Circuit Voltage) High Impedance Low Impedance -35.0 dBV/Pa* -57.0 dBV/Pa* (17.8 mV) (1.4 mV) *1 Pa = 94 dB SPL Switches Locking Press-to-Talk Switch: Activates microphone circuit and an external relay or control circuit. The microphone circuit is normally shorted. Impedance Selection Switch: Double-pole, double-throw slide switch located in the base of the microphone. OVERALL DIMENSIONS FIGURE 3 Net Weight 737 grams (1 lb., 10 oz.) Shipping Weight 1020 grams (2 lb., 4 oz.) Certification Conforms to European Union directives, eligible to bear CE marking; meets European Union EMC Immunity Requirements (EN 50082-1, 1992). REPLACEMENT PARTS Cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R96 Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C31C On/Off Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RK141S OPTIONAL ACCESSORIES Transmit/Monitor Split-Bar Switch Kit . . . . . . . . . RK199S SHURE Incorporated Web Address: http://www.shure.com 222 Hartrey Avenue, Evanston, IL 60202-3696, U.S.A. Phone: 847-866-2200 Fax: 847-866-2279 In Europe, Phone: 49-7131-72140 Fax: 49-7131-721414 In Asia, Phone: 852-2893-4290 Fax: 852-2893-4055 Elsewhere, Phone: 847-866-2200 Fax: 847-866-2585