Section I; Introduction/Specifications; Introduction; General Description - Harris Platinum HT EL 2000LS Technical Manual

Introduction

1.1

General Description

1.1.1
Platinum™ Series The HT EL 2000 watt television transmitter
is an externally diplexed transmitter available in CCIR systems
for M, D/K, B, I, and K.
The transmitter consists of 5 RF amplifier modules, cooling fans,
50 volt power supplies, control interface tray, logic power supply
and an exciter. The exciter includes the transmitter control panel.
Transmitters operate on a 208-240 volt single phase 50 or 60
Hertz. The transmitter assemblies all are mounted in a single
cabinet 183 cm (72 inches) high.

Control and Monitoring

1.2
Transmitters are designed for local, video present control, or
remote/extended operation. VSWR foldback is used to protect
the transmitter RF system. Over temperature protection of RF
modules and module power supplies is standard.

Signal Flow Through the System

1.3
Refer to transmitter block diagram Figure 1-1.
The visual exciter uses IF modulation with pre-correction at
video and IF. The visual signal is amplified by a driver and three
PA modules.
The aural exciter modulates audio baseband and subcarrier in-
puts at aural IF carrier. Optional IF group delay correction is
available for a Notch Diplexer and aural linearization for dual
carrier systems. The aural signal is amplified by a RF driver
amplifier module.

RF Amplifier Modules

1.4
Like aural and visual modules are interchangeable and have
overdrive, over/undervoltage, power unbalance, VSWR, and
overtemperature protection. The modules may be repaired in the
field at the quarter module or component level.

Power Supplies

1.5
The exciter and interface logic utilize linear regulator supplies.
The RF module power comes from power factor corrected
switching supplies in the power module assembly.
888-2457-001
WARNING: Disconnect primary power prior to servicing.

Introduction/Specifications

Cooling

1.6
The main cooling air intake is through the rear door and exhausts
out the top and right side. There are five supply and five exhaust
fans for module cooling. Two other fans are used for heat pipe
cooling.
Removing one module will not affect air flow to other modules.
Each power supply has a fan to draw air from the front of the
transmitter.

RF Output System

1.7
Various diplexing systems are used as the system requires. Har-
monic and image frequency color subcarrier filters are part of the
system.

Optional Equipment

1.8
Single or dual cavity Notch Diplexer
Multichannel sound: NICAM, IRT Dual Carrier and BTSC
Precision Offset
Combined transmitters
Main/alternate transmitters
Second exciter with automatic exciter switcher
Power measurement wattmeter
RF module test fixture
Spare parts, semiconductors and board assemblies
Spare RF modules
Transmitter Remote Control System

Block Diagram

1.9
Figure 1-1 is a block diagram of the HT EL2000LS/HS.

Specifications

1.10
Table 1-1 lists the specificaitons for the HT EL2000LS/HS.
NOTE
Specifications subject to change without notice.

Section I

1-1