The general wiring procedure for tranceiver connections is as follows: Microphone Audio Input Circuit: 1. Connect the WHITE cable lead to the microphone audio input terminal. 2. Connect the SHIELD to chassis or circuit ground of the transceiver (see Guide and CAUTION below). Electronic or Relay Switching Circuit: GROUNDED SWITCHING Most transceivers employ a grounded circuit to switch from the receive to the transmit position. To connect the microphone to such a circuit, proceed as follows: 1. At the end of the cable, connect the RED lead to the terminal used to complete the transmitter circuit. 2. Connect the BLUE lead to chassis or circuit ground of the transceiver (see Guide and CAUTION below). 3. Connect the YELLOW lead to the terminal used to complete the receiver circuit. This will usually be a ground return from the loudspeaker circuit. If a microphone switching contact is not required for loudspeaker ground, insulate (wrap with tape) the YELLOW lead. 4. The BLACK lead is usually not used; insulate the BLACK lead. However, if both a receiver ground and a loudspeaker ground are required, connect the YELLOW lead to loudspeaker ground, and the BLACK lead to the receiver ground. ISOLATED SWITCHING In some transceivers, an isolated circuit is required to switch power supply voltages rather than grounds. If an isolated switching circuit is required, proceed as follows: 1. At the end of the cable, connect the RED lead to the isolated switch contact terminal used to complete the transmitter circuit. 2. Connect the BLUE lead to the terminal used for the switched power supply. 3. Connect the BLACK lead to the terminal used to complete the receiver circuit. If the power supply is not
switched to the receiver circuit by a microphone switching contact, insulate (wrap with tape) the BLACK lead. 4. Connect the YELLOW lead to the loudspeaker ground return. If a microphone switching contact is not required for the loudspeaker ground, insulate the YELLOW cable lead. CAUTION Make certain that the SHIELD and/or the BLUE lead are not connected to chassis ground for those models where the Guide specifies they should be connected to circuit ground. SPECIAL SWITCHING In some transceivers, special switching circuits are required. Three types are described below. In all of the types, before making the required circuit alterations, remove the microphone baseplate by unscrewing the two screws securing it. 1. If a grounded audio input is required in the receive mode, solder a jumper lead between switch terminal 9 and the ground lug (see Figure 1). 2. If both and isolated and grounded transmit circuit are required, along with a grounded receive circuit (see Figure 1): a) Unsolder the WHITE leads from switch terminals 7 and 8.
b) Solder the WHITE leads together, and insulate the
connection.
c) Cut the BLACK cable lead from terminal 1 and solder it to terminal 8.
d) Solder a jumper lead between terminal 7 and the
ground lug. At the end of the cable, the BLUE and RED leads are now the isolated transmit leads; the BLACK lead is the grounded transmit lead; and the YELLOW lead is the grounded receive lead. 3. If both an isolated and grounded receive circuit are required, along with a grounded transmit circuit (see Figure 1):
2
