Service Manual

MM-E 2072-09333-00
2-12
• Voice PTT – PTT from an accessory connected to Micom-Z through the ACCESSORY
connector, transmits the voice signal from the accessory device.
• Data PTT – PTT from a data device, for example, a modem, connected to Micom-Z through
the ACCESSORY connector, causes Micom-Z to switch to the data mode and transmit the
modem signal.
• CW PTT – PTT from a Morse key connected to Micom-Z through the ACCESSORY
connector, causes the radio to switch to the CW (Morse) transmission mode.
In parallel, the radio operating mode is automatically adapted for best performance with the
signal expected for the detected PTT type.
b. Processing of Transmit Signal. See para. 2-1.1.3.1.b.
c. ISB Option. See para. 2-1.1.3.1.c.
d. Generation of RF Transmit Signal. See para. 2-1.1.3.1.d.
2-1.2.3.2 Receive Path
a. Processing of Received RF Signal. See para. 2-1.1.3.2.a.
b. IF Signal Path. See para. 2-1.1.3.2.b.
c. Audio Signal Paths. See para. 2-1.1.3.2.c. The only difference is that an external speaker is used
(this speaker is connected via a branch of the interconnection cable).
2-1.2.3.3 Frequency Conversion Subsystem
The Micom-Z frequency conversion scheme is described in para. 2-1.1.3.3.
2-1.2.3.4 Control Subsystem
The Micom-Z control subsystem includes the main microcomputer subsystem located on the LORD
module, and a microcontroller subsystem located on the CONTROL HEAD module, which are similar
to these described in para. 2-1.1.3.4. The only difference is the use of RS-485 transceivers that transfer
the control channel via the interconnection cable.
2-1.2.3.5 Power Supply Subsystem
The Micom-Z power source is connected via the VDC IN connector to the HI POWER module, which
includes the ON/OFF electronic switch and the input voltage protection circuits.
The ON/OFF switch, integrated with the protection circuits, is controlled by the ON_OFF_CONT line
from the control head. It connects the supply voltage to the internal supply voltage line, SW_BATT,
when the operator turns the Micom-Z on, provided the polarity of the supply voltage is correct, and
within the allowed limits. The SW_BATT line provides power to the local regulators on the other
modules. The supply voltage is also connected via current limiting devices to the ACCESSORY
connector.
The connection of the SW_BATT line to the control head passes through a supply voltage control
circuit, also controlled by the ON_OFF_CONT line: this circuit connects the supply voltage only
when the operator passes through control head ON/OFF button to turn the Micom-Z on. Therefore, if
the interconnection cable, or the control head, is disconnected from the body assembly, Micom-Z is
automatically turned off.