National ncl 2000 service en

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NCL 2000 LINEAR POWER AMPLIFIER

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INDEX

SECTION 1 GENERAL DESCRIPTION ............................................................................................. 3

SECTION 2 INSTALLATION ........................................................................................................ ..... 4

2.1 CAUTION

2.2 Unpacking and Tube Installation

2.3 Power Connection

2.4 Antenna Connection

2.5 ALC Connection

2.6 Exciter Requirements

2.7 Exciter Connections

28 RF Exciter Connection (Transceiver)

2.9 RF Exciter Connection (Separate Transmitter and Receiver
With External Antenna Transfer Relay)

2.10 RF Exciter Connection (Separate Transmitter and Receiver

Vithout External Antenna Transfer Relay)
2.11 Relay Connection

2.12 Ground Connection

SECTION 3 OPERATION .................................................................................................................... 8

.3.1 Explanation of Controls
3.2 Preliminary Adjustment
3.8 CW Tune-Up Procedure
34 SSE Tune~Up Procedure
3.5 AM Tune-Up Procedure

SECTION 4 THEORY OF OPERATION ........................................................................................ 12

4.1 Class of Operation

4.2 Grid Bias Supply

4.3 Input Circuit

4.4 ALC

4.5 Output Circuit

4.6 Metering

4.7 Primary Power Circuits

4.8 CW-SSB Mode Selection

4.9 Antenna and Transmit - Standby Switching
4.10 Cut-Off Bias

SECTION 5 SERVICE INSTRUCTIONS ........................................................................................ 15

5.] Tube Replacement

5.2 Filter Capacitor Board Removal

5 1 Cabinet Removal

5.4 Front Panel and Side Gusset Removal
5.5 Regulator Transistor Change

5.6 Air System Cleaning

5 7 Grid Resistor Tap Change

SECTION 6 TROUBLE SHOOTING ............................................................................................... 17
SECTION 7 PARTS LIST ................................................................................................................ 19