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1. GENERAL INFORMATION
1-1. Introduction and Description
This manual explains the installation, operation and maintenance of the ACOM3x2000A three way, broadband HF
power splitter / combiner.
The ACOM3x2000A is a HF power splitter / combiner which is a passive device designed to sum the outputs of three
HF linear amplifiers into a common load while the amplifiers are driven by a single exciter. For this purpose, the
exciter's (HF transceiver) output power is split in three equal channels, fed to the three amplifier inputs, while the
amplifier outputs are combined and then fed to the common load (antenna). The three splitter output ports as well as
the three combiner input ports are RF
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isolated from each other to eliminate the mutual coupling between the three
amplifiers. All ports are designed for 50 Ohm characteristic impedance.
Using three amplifiers permits powering them from a three-phase mains power line. This would distribute the load
among the three power line phases and is preferred to the case with a single-phase power line but loaded three times
greater. An additional benefit with a three-phase power line is considerable reduction of the mains parasitic
modulation of the combined RF signal.
For proper operation, the combiner requires three amplifier outputs having equal amplitudes and phases, i.e. three
coherent signals. This is achieved by the use of three identical amplifiers in the three channels . For best results we
recommend three automatic amplifiers of the type ACOM2000A. Manual tune amplifiers with a precise tuning
indicator like ACOM1200, ACOM1000, ACOM1010 or ACOM1011 can be used too. All these models use a
broadband input network which sets minimum phase differences between the units.
An automatic protection circuit is implemented in the ACOM3x2000A, which monitors the three amplifier outputs
during operation. In case of an imbalance, the protection trips thus cutting the drive to the amplifiers and switching the
transceiver output to an internal 50 Ohm dummy load. The imbalance power, both input and output, is swamped by
powerful resistors until the protection trips. Therefore the transceiver and the three amplifiers are well protected.
After fixing the trouble you can resume operation by pressing the button RESET.
1-2. Owner Assistance
If assistance is needed, you should contact your local dealer first. If you still have an issue, you need to discuss with one
of ACOM's specialists. The contact information is as follows: fax: + 359 2 920 96 56, e-mail [email protected],
or by mail: Blvd. ”Nikola Mushanov”-151, 1330 Sofia, Bulgaria.
1-3. Equipment Supplied and Options
The ACOM3x2000A and accessories are shipped in a single cardboard carton. The package contains:
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ACOM3x2000A splitter / combiner - 1 pc
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Power supply 12V/0.5A for 100-240V mains voltage - 1 pc
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3 m RG58 coaxial cable with PL259 connectors - 1 pc
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1.5 m RG58 coaxial cable with PL259 connectors - 3 pcs
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1.5 m RG213 coaxial cable with PL259 connectors - 3 pcs
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3 m RCA / RCA connectors cable - 2 pcs (or 1pc paired cable)
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1.5 m RCA / RCA connectors cable - 6 pcs (or 3 pcs paired cable)
A metal rack, designed for housing three ACOM2000A amplifiers and the ACOM3x2000A splitter / combiner is
available as separately purchasable option.
1-4. Features
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Sums three amplifiers outputs;
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Up to 5000W PEP output power.