Specifications

xii 888-2857-001 5/9/13
WARNING: Disconnect primary power prior to servicing.
Glossary of Terms
Analog Input Board (AIB):
An optional circuit card for the modulator section of the low power unit (LPU). It
provides the necessary interface to allow the modulator to accept analog video and
audio inputs according to the PAL, NTSC, or SECAM standards.
ASI (Asynchronous Serial Interface):
A streaming format used to carry the MPEG transport stream from the network
origination point to the transmitter for modulation onto the RF carrier(s).
ATSC (Advanced Television Subcommittee):
A digital television standard featuring a single, vestigial-sideband carrier and an 8-
VSB modulation constellation. The transport stream format may be either
SMPTE310 or ASI:
The data rate before forward error correction is 19.392658 Mbit/s. The transmitted
data rate with error correction is 32.28 Mbit/s.
Back Porch:
The portion of the analog video horizontal line waveform following the sync pulse
but before the start of active video.
Band III:
The VHF radio frequency band from 174 MHz to 230 MHz. In this manual, taken to
mean the broadcast band from 168 MHz to 242 MHz covered by the VAX
transmitter.
BPF (Band pass filter):
A high power filter centered about the desired channel bandwidth and located at the
transmitter output port to eliminate out-of-band intermodulation products arising
from the power amplification process. Also commonly referred to as the mask filter
or critical mask filer.
CAN (Controller Area Network):
A serial communications standard designed to allow microcontrollers and devices
to communicate with each other.