Acom 1500 User manual

ACOM 1500
HF + 6m
Linear Amplifier
User's Manual
Installation, Operation
and Maintenance
August 2021
OUTSTANDING HF POWER PRODUCTS

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
Page 2of 52 | S e c t i o n ABOUT DOCUMENTATION
August 2021
This manual is for electronic distribution mainly.
If you have it on paper and you no longer need it, please, recycle it!
The latest versions of our User's Manuals are available at
www.acom-bg.com

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
August 2021
S e c t i o n ABOUT DOCUMENTATION | Page 3of 52
ABOUT DOCUMENTATION
All ACOM documentation (including manuals, brochures, specifications, descriptions, presentations, video
materials, etc.) are based on the latest available information at the time of creation of our documents.
As we always strive to constantly improve and update our products, ALL PRODUCTS, PRODUCT
SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE. ACOM reserves the right to make changes and
improvements at any time without further notice or obligation to notify any person or organization of such
revisions or changes, made in order to improve the reliability, function, quality and design, and/or
performance of the ACOM products and services.
Further, this User's Manual is provided AS IS and ACOM shall not be liable for possible errors contained
herein.
This manual supersedes all previous editions, which thereby become invalid.
The cover images used in the manual are illustrative only.
We are continuously striving to improve our documentation, but nobody is perfect.
And our documentation is not an exception of this rule.
Have you found any errors or would you like to suggest changes in our documentation?
Please help us by sending your suggestions to the following e-mail address:
[e-mail]
The latest versions of our User's Manuals are available at
www.acom-bg.com
We highly recommend you to use this manual in electronic form as PDF-file instead of printed version. The
PDF-file is easy to read on any computer, tablet, smart phone or other similar device. In the PDF file you will
find the necessary information very fast due to context-oriented links (marked in orange) inside the file,
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User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
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August 2021
Title of Documentation
ACOM 1500 HF + 6 m Linear Amplifier
User's Manual
Installation, Operation and Maintenance
Type of Documentation
User's Manual
Purpose of Documentation
This manual explains Installation, Operation and Maintenance of the
ACOM 1500 HF + 6 m Linear Amplifier.
Record of Revisions
Description
Release Date
Notes
ACOM 1500 User's Manual
-
First edition
ACOM 1500 User's Manual
-
Second edition
ACOM 1500 User's Manual
17.04.2016
Third edition
ACOM 1500 User's Manual
28.08.2020
Fourth edition
ACOM 1500 User's Manual
13.08.2021
Fourth edition, R02
Validity
The specified data is for product description purposes only and may not be
deemed to be guaranteed unless expressly confirmed in the contract. All
rights are reserved with respect to the content of this manual and the
availability of the product.
Copyrights
© 2021 ACOM Ltd.
Copying this document, giving it to others and the use or communication
of the contents thereof without express authority, are forbidden.
Offenders will be held liable for infringement of any intellectual property
of ACOM Ltd. and all damages which may rise as a result.
Published by
ACOM Ltd.
Bulgaria | Bozhurishte 2227
Sofia-Bozhurishte Economic Zone | 6 Valeri Petrov Str.
GPS coordinates: 42.748616о| 23.209801о
Web: www.acom-bg.com
E-mail: [e-mail]
Note
This manual has been printed on chlorine-free bleached paper.

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
August 2021
S e c t i o n ABOUT DOCUMENTATION | Page 5of 52
Contents
ABOUT DOCUMENTATION ................................................................................................................................ 3
1. GENERAL INFORMATION........................................................................................................................... 7
1.1. Introduction and Description.......................................................................................................... 7
1.2. Owner Assistance............................................................................................................................ 8
1.3. Equipment Supplied........................................................................................................................ 8
1.4. Features........................................................................................................................................... 8
1.5. Safety Considerations, Explicit Definitions.................................................................................... 10
2. INSTALLATION.......................................................................................................................................... 13
2.1. Unpacking and Initial Inspection................................................................................................... 13
2.2. Line Voltage Selection................................................................................................................... 13
2.3. Amplifier Location Selection ......................................................................................................... 14
2.4. Connections................................................................................................................................... 15
2.5. Installation of External Fan (option).............................................................................................. 19
3. POWER ON, CONTROLS AND INDICATORS.............................................................................................. 20
4. OPERATION.............................................................................................................................................. 23
4.1. Turning ON and OFF...................................................................................................................... 23
4.2. Changing OPERATE and STANDBY Modes..................................................................................... 24
4.3. Antenna Change............................................................................................................................ 25
4.4. Tuning............................................................................................................................................ 25
4.5. Continuous Carrier Modes ............................................................................................................ 29
4.6. ON LINE Information Screens and Control Functions ................................................................... 30
4.7. Auto-Protection System................................................................................................................ 30
5. OFF LINE MODE ....................................................................................................................................... 32
5.1. Display Brightness Control ............................................................................................................ 32
5.2. Auto-Operate Enabling and Disabling........................................................................................... 32
5.3. Antenna Output Assignment......................................................................................................... 33
5.4. Reading Auto-protection Signatures............................................................................................. 33
6. MAINTENANCE ........................................................................................................................................ 34
6.1. Periodic Maintenance ................................................................................................................... 34
6.2. Cleaning......................................................................................................................................... 35

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
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6.3. Fuse Replacement......................................................................................................................... 35
6.4. Tube Replacement ........................................................................................................................ 37
6.5. Simplified Schematic Diagram....................................................................................................... 38
6.6. Troubleshooting ............................................................................................................................ 40
7. SPECIFICATIONS....................................................................................................................................... 42
7.1. Parameters.................................................................................................................................... 42
7.2. Functions....................................................................................................................................... 44
7.3. Storage and Shipment................................................................................................................... 45
7.3.1. Storage Environment....................................................................................................... 45
7.3.2. Shipping Size and Weight ................................................................................................ 45
7.3.3. Transportation................................................................................................................. 45
7.3.4. Returning to the Service Provider ................................................................................... 45
7.4. Information on Disposing and Recycling of Old Electrical and Electronic Equipment.................. 46
NOTES.............................................................................................................................................................. 47
Figures
Figure 2-1 Rear panel - Connections ............................................................................................................... 15
Figure 2-2 External fan .................................................................................................................................... 19
Figure 3-1 Front panel - Display and Controls................................................................................................. 20
Figure 3-2 Information screens and control functions structure.................................................................... 21
Figure 4-1 Using TRI tuning aid........................................................................................................................ 28
Figure 6-1 Simplified schematic diagram ........................................................................................................ 39
Figure 7-1 Packaging cardboard box ............................................................................................................... 45
Tables
Table 2-1 Amplifier individual data ................................................................................................................. 13
Table 4-1 Approximate tuning presets............................................................................................................ 27

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
August 2021
S e c t i o n GENERAL INFORMATION | Page 7of 52
1. GENERAL INFORMATION
Congratulations on purchasing one of the finest HF amplifiers in the world today.
ACOM is pleased that you have chosen one of our products, and we will endeavor to provide you with the
information and support you need to enjoy your purchase for many years.
We urge you to read all of the following materials before you embark on operating your new amplifier.
1.1. Introduction and Description
This manual explains:
•Installation
•Operation and
•Maintenance
of the ACOM 1500 HF + 6 meter linear amplifier.
The ACOM 1500 is a complete and self-contained linear amplifier that covers all amateur bands from 1.8
through 54 MHz and provides over 1500 W PEP (1200 W continuous carrier) output power with less than
85 W exciter drive. Antenna SWR up to 3:1 is acceptable with 1200 W forward power. Tuning is
substantially simplified by a plate-load True Resistance Indicator (TRI) and by an automatically controlled
input attenuator. Operating parameters are displayed by a multi-functional high brightness OLED display.
Full break-in transmit/receive switching (QSK) is standard.

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
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August 2021
1.2. Owner Assistance
If assistance is needed, you should contact your local dealer first. If necessary, your dealer will contact ACOM
for additional guidance.
If you still have an issue you need to discuss with one of ACOM's specialists, the contact information is as
follows:
ACOM Ltd.
E-mail: [e-mail]
Bulgaria | Bozhurishte 2227
Sofia-Bozhurishte Economic Zone | 6 Valeri Petrov Str.
GPS coordinates: 42.748616о| 23.209801о
1.3. Equipment Supplied
The ACOM 1500 amplifier and this User's Manual are shipped in a cardboard carton.
1.4. Features
•Easy to operate
The TRI (True Resistance Indicator) is a powerful tuning aid which, together with the automatically
controlled input attenuator, helps the operator to quickly and precisely match the antenna impedance
to the optimum tube load impedance (5-10 seconds typically). The auto-operate function (when
enabled) maintains the amplifier in the OPERATE mode for you, thus saving manual operations and
time.
•No antenna tuner needed
No heavy outboard antenna tuners required for antenna SWRs up to about 3:1. Your amplifier will
enable you to change antennas virtually instantaneously and allow you to use your antennas over
wider frequency ranges.
•User-friendly and durable
An amplifier that is both user-friendly and that looks after itself. It is designed to safely withstand up
to 300 W reflected power, up to 100 milliseconds duration of drive spikes, drive RF "tails" after a PTT
or KEY release, operator's inadvertent tuning errors etc. The amplifier also will not cease to function
with a "soft" AC mains and will deliver more than half power at only 85% of nominal mains voltage. It
can withstand voltage drops (down to zero Volts) for up to 10 milliseconds and can tolerate 15% mains
voltage spikes, which is especially important on Field Day, during DXpeditions, and at portable
operating events where emergency power is relied upon.
•OLED comment display
All amplifier status indications are explained via detailed text displayed on the OLED (Organic Light
Emitting Diode) Display. The upper line on the OLED display always reads peak forward power. LED
indicators are provided for: OPERATE mode, attenuation-on (ATT), transmit (TX), selected antenna
output (1, 2, or 3), and ON/OFF conditions.
•Easy antenna selection
Three antenna outputs are selectable using a push-button on the front panel.

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
August 2021
S e c t i o n GENERAL INFORMATION | Page 9of 52
•Easy maintenance
Signatures of the amplifier internal status are stored in a nonvolatile memory for 7 most recent auto
protection trips. This information can be forwarded to your dealer for diagnostics. Using an EXCEL
application (available from ACOM or your dealer free of charge) and a PC you can decode the
signatures by yourself, too.
•Less noise in the shack
The input bypassing and the vacuum antenna relays are virtually silent even in the QSK CW mode due
to their special mounting.
•Efficient tuning
Less QRM and improved Electro Magnetic Compatibility during tuning. Amplifier tuning can be
achieved in less than 10 seconds at a quarter of nominal output power.
•Transceiver-independent
The amplifier operates without special signals from the transceiver - "Ground on TX" (PTT) and 85 W
RF drive power are sufficient.
•Broadband input matching
Broadband input matching circuit design provides excellent transceiver loading over the entire
spectrum, from 1.8 MHz up to 54 MHz.
•Single tube operation
Uses a single 4CX1000A/8168 ceramic and metal radial beam tetrode with plate dissipation of 1000 W
(forced air cooled, grid-driven), which is specifically designed for class AB1 RF linear amplifier
operation.
•Tube protection
Permanent monitoring includes protection of plate and grid voltages and currents, as well as exhaust
air temperature. The Bias Optimizer decreases the heat dissipated from the tube, and there is
automatic protection against overheating in accordance with specifications of the tube manufacturer.
•Output RF arc protection
Output RF arc protection is employed. This important feature safeguards the amplifier, antenna,
antenna selector, and tuner against severe damage in case of possible breakdown.
•High voltage protection
High voltage power supply inrush current limitation. This feature reduces the risk to sensitive devices
connected to the same mains circuit (important when used portable) when the amplifier is turned on.
Moreover, the amplifier can be configured for 8 different nominal line voltages: 100, 110, 120, 200,
210, 220, 230, or 240 VAC, 50 or 60 Hz.
•Continuous monitoring and/or selectable measurement
Continuous monitoring and/or selectable measurement of the 12 most important parameters of the
amplifier, exciter, and the selected antenna via the OLED display.

User's Manual | ACOM 1500 | HF + 6 m Linear Amplifier
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August 2021
1.5. Safety Considerations, Explicit Definitions
The ACOM 1500 HF + 6 meters Linear Amplifier is a Safety Class I unit regarding protection against electric
shock. The third grounding lead of its mains cord (colored yellow with two green stripes) and the ground
stud on the rear panel of the amplifier (marked GND, see Figure 2-1 Rear panel - Connections, Pos. (a)) must
be connected to the station's grounding system for safe operation.
The amplifier is designed to meet international safety standards and complies with CE safety and
electromagnetic compatibility requirements, as well as FCC regulations.
This User's Manual contains information, warnings (signal words Danger, Warning, Caution and Notice) and
instructions, related to hazards, that should be followed by the user in order to ensure safe operation and
to keep the amplifier in a safe working condition at all times.
The EXPLICIT DEFINITIONS described below apply to this User's Manual:
DANGER
These notes call attention to a procedure or instructions which, if not correctly
performed, will result in serious personal injuries and even death.
WARNING
These notes call attention to a procedure or instructions which, if not correctly
performed, could result in serious personal injuries and even death.
CAUTION
These notes call attention to a procedure or instructions which, if not correctly
performed, could result in minor or moderate personal injuries.
NOTICE
These notes call attention to a procedure or instructions which, if not correctly
performed, could result in property damage or equipment damage not exclusively to
the amplifier but also to connected equipment.