QRO Technologies HF-2500DX User Manual

QRO HF-2500DX LINEAR AMPLIFIERQRO HF-2500DX LINEAR AMPLIFIER
INSTRUCTION MANUAL
QRO TECHNOLOGIES, INCQRO TECHNOLOGIES, INC
1117 West High Street
P.O. Box 939
Bryan, OH 43506 USA
Tel & Fax: (419) 636-2721
E-mail: sales@qrotec.com
Internet: http://www.qrotec.com
PUBLICATION DATE: October 1996
COPYRIGHT 1996 BY QRO TECHNOLOGIES, INC. ALL RIGHTS RESERVED.
THIS MANUAL OR ANY PART THERE OF MAY NOT BE REPRODUCED IN ANY FORM
WITHOUT PERMISSION FROM QRO TECHNOLOGIES, INC.

QRO Technologies HF-2500DX Specifications

General

Input Power	100W maximum
Power Supply	240V AC, 50/60Hz
Cooling	Forced Air
Power Output	2500W PEP SSB, 2000W CW
Output Power	2500W PEP SSB, 2000W CW
Input Impedance	50 ohms
Output Impedance	50 ohms
Gain	13 dB
Harmonic Suppression	-50 dB or better
IMD (3rd Order)	Better than -30 dB
Frequency Coverage	1.8-30 MHz

Summary

Warranty Information

Proprietary Notice

Safety First: Always Think Safety

Unpacking and Inspection Procedures

Reshipment Instructions

Top Cover Removal Guide

Transformer and Tube Installation

Line Voltage Selection and Wiring

Introduction to the Amplifier

Operating Location Recommendations

AC Line Power Considerations

Antenna Connection

Grounding Requirements

Equipment Interconnections

Safety Interlock Switch Function

Driving Power Guidelines

Tube Precaution

Reading the Meters

Front Panel Switches and Controls

Initial Power Up Sequence

Tune Up Procedure

Adjusting Output Power with ALC

Periodic Maintenance

Troubleshooting Chart

Circuit Descriptions

Power Supply Circuit

Details the power transformer, fuses, and soft-start circuit for amplifier operation.

Plate Voltage Circuit

Explains the high-voltage rectifier and filtering circuit for plate voltage supply.

Tube Filament Supply

Describes the filament supply voltage and heating requirements for the amplifier tubes.

12 VAC Supply Circuit

Details the 12 VAC secondary winding of T2 and its use in DC supply circuits.

120 VAC Isolation Supply

Explains the 120 VAC secondary winding of T2 providing isolated supply for the 120 VDC power supply.

Control Grid Bias Circuit

Describes the circuits providing cutoff bias and transmit bias for the amplifier's control grids.

Screen Grid Bias Circuit

Explains the screen grid bias generation using a voltage doubler and zener diodes.

RF Input Circuits

Details the RF input path in standby and transmit modes, including bypass and tuning.

Tube Configuration

Describes the tube connections, RF driving power, and cooling for the amplifier's tubes.

RF Output Circuits

Explains the tuned output circuit (pi-l network), impedance matching, and harmonic suppression.

ALC Circuit Operation

Details the ALC circuit function, its control, and how it reduces overdrive.

Screen Grid Meter Circuit

Explains how screen grid current is measured using meter M-2 and shunt resistors.

PV (Plate Voltage) Meter Circuit

Describes the voltage divider and components used to measure plate voltage with meter M-1.

IP (Plate Current) Meter Circuit

Details how plate current is measured using meter M-1 and a voltage drop across a resistor.

SV (Screen Voltage) Meter Circuit

Explains the voltage divider and components used to measure screen voltage with meter M-1.

RF I/O Switching and Bias Relay Circuits

Describes the keying circuit, T/R relays, and bias relay switching.

Screen Grid Protection Circuit

Explains the circuit that protects against excessive screen grid current and its reset mechanism.