MOUNTING The 885TT is provided with a rear-case hang-up button for use with a mounting bracket on or near associated equipment. Heavyduty, chrome-plated mounting brackets are available in quantities of three as Shure Part No. RK6MB. IMPORTANT: The microphone hang-up button is connected to the blue cable conductor for radios with microphone hang-up sensing. MICROPHONE CABLES The 885TT can be used with various MODULINK microphone cables. Each cable has a modular microphone plug on one end and the user�s choice of equipment plugs on the other. The MODULINK Cordset Table supplied with the 885TT lists the most popular radios available and the cordset (ALM-) designed for use with each. Note that the ALM-1 has no connector on the equipment end; it can be wired as needed.
DTMF level adjust (C)
microphone sensitivity adjust (B) cable release (A) MICROPHONE CASE REAR FIGURE 5 Voice Transmission 1. Hold the microphone comfortably in the hand, positioned so that the Top-Talk Sound Channels at the top of the case are near the mouth. The clearest sound is often obtained with the microphone at the corner of the mouth, with the cable away from the face. 2. Press the push-to-talk button and make sure the equipment is in the transmit mode before speaking. 3. Release the push-to-talk button before dialing. Dialing
MODEL ALM-1 CABLE WIRING FIGURE 4 MICROPHONE CONNECTOR WIRING Pin Color Function Pin Color Function 1 2 3 4 � Red Yellow Blue N.C. Bias (+), DC Audio Out PTT Switch Hang-up Button 5 6 7 8 Black White Drain � PTT Switch Ground Audio Ground N.C.
1. Do not depress the push-to-talk button. 2. Press the desired keypad buttons in sequence. A high-pitched tone will confirm that the code has been transmitted. 3. When the first keypad button is pushed, the transmitter is automatically keyed. The transmitter will remain keyed for approximately 1.5 seconds after the button is released. MODIFICATIONS Certain applications require that the 885TT be internally modified. These modifications should be performed by qualified service personnel only. CAUTION: This microphone contains static-sensitive semiconductor devices. All work must be performed at a static-free work station using properly grounded equipment. Soldering operations must be performed using a fine-pointed, lowwattage soldering iron. To perform internal modifications, disassemble the 885TT as follows. 1. Turn the equipment power off. 2. Remove the cable from the 885TT as previously described. 3. Remove the four screws from the rear of the 885TT case. 4. Holding the 885TT with the rear toward you and the cable connector downward, carefully remove the case rear from the front. Make certain the rear printed-circuit board does not become disconnected from the remaining boards attached to the case front. Carefully pivot the case rear to the right. Five wires remain attached between the printed-circuit boards (retained in the case front), and the switch and lug attached to the case rear. This exposes the solder side of the rear printed-circuit board. 5. Perform the required modification. 6. Carefully reassemble the case rear to the case front, guiding the front pin of the push-to-talk button into the round pivot recess of the case front. Reposition wires as necessary to make certain none are pinched between the case halves. 7. Replace the four screws and reinstall the 885TT.
The cable is attached to the 885TT by inserting the modular telephone-type plug in the microphone jack until it locks. To remove the cable from the microphone, insert the small screwdriver supplied with the 885TT in rear case hole �A� just above the cable jack (see Figure 5) to unlock the plug and withdraw the plug from the jack. ADJUSTMENTS After connection to the communications equipment and with equipment power turned on, the microphone sensitivity and DTMF output levels should be adjusted with the supplied screwdriver as follows. 1. MICROPHONE SENSITIVITY: Press the push-to-talk button and speak normally into the microphone while observing transmitter modulation. Adjust the microphone sensitivity control (rear case hole �B� in Figure 5) and repeat the talk test as required. 2. DTMF OUTPUT: Do not press the push-to-talk button. Depress and hold down a keypad button for a continuous tone. Adjust the DTMF output control (rear case hole �C� in Figure 5) as required. OPERATION Operation of all microphone and DTMF functions requires that the 885TT is connected to the communications equipment and that the equipment power is turned on. Power application can be verified by observing keypad LED backlighting.
