Operations and Maintenance Manual
Table Of Contents
- Release control record
- Section 1: Description
- Section 2: Operating the transmitter
- User Interfaces
- Viewing Transmitter Log
- Viewing AUI Tool Menu Panels
- Viewing Real-Time Meters
- Managing Presets
- Enabling Remote Control
- Resetting Alarms
- Viewing Transmitter Status
- System Settings
- System Settings - Front Panel UI
- Setting User Accounts
- User Settings - AUI
- User Settings - Front Panel UI
- Configuring Remote Inputs and Outputs
- Scheduler
- Audio Player
- Enabling and Operating the Orban Audio Processor
- Figure 2-1 : VS Transmitter Front Panel Display Menu Tree (Sheet 1 of 2)
- Figure 2-2 : VS Transmitter Front Panel Display Menu Tree - Edit Presets (Sheet 2 of 2)
- Figure 2-3 : VS Transmitter AUI Flow Diagram
- Section 3: Routine maintenance
- Section 4: Non-standard maintenance
- Section 5: List of terms
VS300 Operations and Maintenance Manual Description
Page 1-4 Issue 10.0 2019-01-18
• provides local and remote interfacing for the transmitter. Local interfacing is per-
formed via the front panel display (U5) - a 4 x 20 character LCD display - and its adja-
cent keypad. The UI contains a menu-based series of pages that serve specific functions.
Similar interfacing, as well as more advanced functionality, is available on a remotely
accessed AUI.
Except for the RF drive signal, all signals going between the exciter, RF drive and RF power
stages are passed through the interface PWB (A3).
RF drive stage
See also electrical schematics Figure
SD-2
and
SD-4
.
The RF drive stage is comprised of exciter circuitry within the exciter/control PWB (A1) and
the pre-amp PWB (A4).
The pre-amp PWB accepts the low level RF Drive output from the exciter/control PWB (A1).
Its RF output is controlled by the Pre-Amp V input (set at +48 V) and Pre-Amp Bias output
from the exciter/control PWB (A1). The output of the pre-amp PWB (nominal 10 W) is
applied to the RF power stage’s PA PWB. Cooling air for the pre-amp PWB is provided by
cooling fan B1.
RF power stage
See also electrical schematics Figure
SD-2
and
SD-5
.
The RF power stage accepts the intermediate RF drive signal from the RF drive stage and
generates the final RF output. It consists of a PA (power amplifier) PWB (A5), a low pass filter
PWB (A6), and an output power probe (A7).
PA PWB
See Figure
SD-5
. The PA PWB (A5) is a push-pull RF power amplifier. It is capable of
providing 100 W of RF power in the FM broadcast band (88 to 108 MHz). The RF output is
controlled by the PA V level generated by the power supply module, and the PA Bias output
from the exciter/control PWB (A1). Cooling air for the PA PWB is provided by fan B1.
Low pass filter PWB
See Figure
SD-2
. The low pass filter PWB (A6) accepts the output of the PA PWB and
attenuates harmonics before applying a filtered RF signal to the output power probe (A7).