MODIFICATIONMICROPHONE CONNECTOR WIRING
Pin ColorFunctionPin Color Function
The Monitor switch as provided is normally closed for ra-
dios with scanning or CTCSS functions that open when1NC--5BlackPTT
the switch is depressed. For radios that require a normallySwitch
Ground
open (closed circuit when the microphone Monitor switch
is depressed) such as many Ericsson/GE models, per-2RedBias (+), DC6WhiteAudio
form the following modification.Audio Out
3Yellow PTT Switch7DrainGround
1. Remove the baseplate by removing the screws secur-
ing it to the microphone.4BlueMonitor8NC--
2. Locate the yellow wire from the printed circuit board toCONNECTIONS
the monitor switch. The 550T Series II is designed to operate with two-way
radio sets with input circuits similar to those in Figure 2.
3. Unsolder the yellow wire from the top terminal of the
When wiring ALM-1 cables with connectors for radios not
monitor switch and resolder it to the lower open termi-
listed in the table, modular connector pin 2 is to be used
nal of the monitor switch.for the dc bias resistor on the input.
5601 K
4. Replace the baseplate and screws.
PIN 2
15 ?F9.6 VDC
MICROPHONE CABLES
The 550T Series II can be used with various MODU-
LINKL microphone cables. Each cable has a modular mi- PIN 7
crophone plug on one end and the user?s choice of equip-
ment plugs on the other. The MODULINK Cordset TableFIGURE 2
supplied with the 550T Series II lists the most popular ra-
dios available and the cordset (ALM-) designed for useADJUSTING OUTPUT LEVELS
with each. Note that the ALM-1 has no connector on theTo adjust the output level, proceed as follows:
equipment end; it can be wired as needed.1. Insert a screwdriver into the sensitivity control poten-
tiometer, located in the microphone base (see Figure 3).
2. Rotate the control counterclockwise to increase sensi-
tivity or clockwise to decrease sensitivity.
7 8
SENSITIVITY
ADJUST
(CCW MAX.)
MODEL ALM-1 CABLE WIRINGMODULINK
CABLE RELEASE
FIGURE 1
The cable is attached to the 550T Series II by inserting the
FIGURE 3
modular telephone-type plug in the microphone jack until it
locks. To remove the cable from the microphone, insert theINTERNAL CONNECTIONS
small screwdriver supplied with the 550T Series II in bottomThe circuit board layout is shown in Figure 6 and the in-
case hole adjacent to the cable jack (see Figure 3) to unlockternal electrical connections are shown in Figure 7. A sche-
the plug and withdraw the plug from the jack.matic diagram of the circuit board is shown in Figure 8.
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