VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.2 2021-01-14 PAGE 2.1.1
SECTION 2.1: DESCRIPTION
This section provides a high-level description of the transmitter’s key sections. The transmitter circuitry
is subdivided into four basic stages:
Ac-Dc Power Stage
Control/Excitation Stage - see page 2.1.4
RF Stage - see page 2.1.5
Refer to the functional block diagram, Figure 3.1.1 on page 3.1.9.
VX150 to VX2 Electrical Schematics
Some descriptions in this section refer to electrical schematics (SD-#s). These are located in Section 4 of
the VX150 to VX2 Troubleshooting Manual.
Ac-Dc Power Stage
See electrical schematic Figure SD-1. The ac-dc power stage provides power to operate the low voltage
power supply, which generates the +12 dc voltage that is used throughout the transmitter. This supplies
the voltage to operate cooling fans, IPA and power the PWBs. The ac-dc power stage also contains a dc
power supply that provides positive dc voltage (PA volts) for the transmitter's RF power amplifier. The
output voltage range of the dc power supply varies with the model. For VX150 to VX600 transmitters,
the output voltage range is between +18 and 53 V dc. For VX1to VX2 transmitters, the output voltage
range is between +23 and 65 V dc.
For normal operation, VX150 to VX600 transmitters accept a single-phase, 90 - 265 V ac (220 V ac
nominal) ac input voltage.
For normal operation, VX1 to VX2 transmitters accept a single-phase, 185 - 265 V ac (220 V ac nominal)
ac input voltage.
NOTE
: VX1 to VX2 transmitters can operate from a 90-185 V ac input,
but will have reduced output
power.
The ac-dc power stage consists of Power Supply Interface PWB (A4), low voltage power supply (LVPS)
(U2) and power supply (U3).
