Acom 2000R User manual

C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA(02)540571,540793 C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA(02)540571,540793
C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA(02)540571,540793
C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA(02)540571,540793
C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA(02)540571,540793
C987654321M 987654321Y987654321K 987654321 ' AGORA(02)540571,540793' AGORA [phone],540793
AUTOMATIC HF LINEAR AMPLIFIER
ACOM
Bul. Nikola Mushanov 151
1330 Sofia
Bulgaria
phone: [phone]
fax: [phone]
e-mail: [email protected]
WEB: www.acom-bg.com November 2009
Printed in Bulgaria
OPERATING MANUAL

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Table of Contents
1. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1-1. Introduction and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1-2. Owner Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1-3. Equipment Supplied and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1-4. Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1-5. Safety Considerations, Explicit Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2-1. Unpacking and Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2-2. Line Voltage Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2-3. Transformer Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2-4. Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2-5. Installation of Optional Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3. POWER ON, RCU CONTROLS, INDICATORS AND MENUS . . . . . . 11
4. MAIN MENU, FREQUENCY AND ANTENNA SELECTION . . . . . . . 13
4-1. AUTO TUNE sub-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4-2. MANUAL TUNE sub-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4-3. MEASURE sub-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4-4. SERVICE sub-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4-5. Erasing USR segments (return to DEF- tunings) . . . . . . . . . . . . . . . . . . . . . 20
5. OFF-MENU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5-1. HELP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5-2. CALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5-3. INFO (INFO BOX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5-4. LOCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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5-5. CLR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5-6. DEF (Defaults) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5-7. Erasing Nonvolatile Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6. MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6-1. Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6-2. Backup Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6-3. Fuses Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6-4. Tubes Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6-5. The ACOM2000A Simplified Schematic Diagram . . . . . . . . . . . . . . . . . . . . . 25
6-6. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7-1. Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7-2. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7-3. Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8. BRIEF MENU GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

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1. GENERAL INFORMATION
1-1. Introduction and Description
This manual explains the installation, operation and maintenance of the ACOM2000A automatic HF
linear amplifier.
The ACOM2000A is a complete and self-contained linear amplifier which covers all amateur bands
from 1.8 through 30MHz, has automatic self-tune capability, and provides up to 1500W output power
with less than 60W exciter drive. In addition, it has automatic antenna impedance matching capability
for loads up to 3:1 VSWR (2:1 on 160 meters). It features a Remote Control Unit (RCU), contains
nonvolatile memory for settings on up to ten different antennas per frequency segment, and offers
command capability for use with an external automatic antenna selector and/or automatic antenna
tuner. Transmit / receive switching is capable of full break-in operation (QSK) via an internal vacuum
relay.
All indicators and controls (except the primary mains switch and indicator) are available via the RCU.
All command input to the RCU is menu-driven.
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], [e-mail] or by mail: blvd.”Nikola Mushanov”-151, 1330 Sofia,
Bulgaria.
1-3. Equipment Supplied and Options
The ACOM 2000A amplifier is shipped in two cardboard cartons. One carton contains the power
transformer; the second carton contains the amplifier. The remote control unit (RCU) is shipped inside
the amplifier in the area where the power transformer will be mounted.
There are three separably-purchasable options available. They are an auxiliary EXTERNAL FAN for
continuous modes of operation (rear panel mount), a DOS APPLICATION for program control via
personal computer and the TECHNICAL SUPPLEMENT to this manual, containing electrical diagrams,
technical details on operation and maintenance, as well as a list of command set and local network rules
for RS232 operation.
The Automatic antenna selector ACOM 2000S and Remote antenna switch ACOM 2000SW are
especially designed to complete your ACOM system.
1-4. Features
zEasy to operate. No operator intervention is required when matching antennas or when changing
frequency. Thus the risk of inadvertant errors, such as incorrect antenna selection or failure to change
band switch, is eliminated.
zLCD comment display. All amplifier status indicators are explained via detailed text diplayed on the
dot-matrix, back-lighted liquid crystal display (LCD) on the RCU. The HELP sub-menu gives on-board
technical assistance and troubleshooting suggestions, power-on hours etc. LED strips readout direct
peak forward and reflected power. LED indicators are provided for OPERATE/STANDBY and for fault
conditions.

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zEasy maintenance. Information on the amplifier internal status is stored in an "INFO BOX" for the
12 most recent protection faults. This information can be forwarded automatically via telephone to
your dealer for phone-line remote diagnostics. Using the DOS APPLICATION option and a PC you can
read the INFO BOX in a file and send it via INTERNET as well.
zLess QRM, improved Electro Magnetic Compatibility during tuning. Retuning can be achieved in two
ways: without any transmission, manually via the RCU; or with a very short transmission - a single word
on SSB or a dot (even at 40 wpm) on the new frequency is enough to change bands or segments
automatically. Antenna matching is completed in less than 3 seconds at a quarter of nominal output
power.
zSaves space on the operating table. Since the amplifier is controlled by the RCU, the main unit can
be located up to 3 meters from the operating position.
zOperates automatically without special signals from the transceiver - “ground on TX” and 60W RF
drive power are sufficient.
zBroadband input matching circuit resulting in very good load to the transceiver over the entire short
wave spectrum.
zUses two 4CX800A (GU74B) Svetlana high performance ceramic-metal tetrodes with plate dissipation
of 800W each (forced air cooling, grid-driven).
zACOM maintains strict adherence to the tube manufacturer’s specifications for cooling and for the
sequence of applying and removing the different tube voltages. Starting filament current is limited, and
there is constant monitoring and protection of all supply voltages and currents. The Bias Optimizer
decreases the heat dissipated from the tubes, and there is automatic protection against overheating or
insufficient air flow.
zA novel and innovative output RF Arc protection is employed. It safeguards the amplifier, antenna,
antenna selector and tuner against severe damage in case of possible break down.
zHigh voltage power supply inrush current protection which eliminates the danger of affecting sensitive
devices, connected to the same mains circuit. The amplifier can be configured for 5 nominal line voltages:
100, 120, 200, 220 and 240VAC (50 or 60Hz).
zContinuous measuring and/or monitoring of 20 most important parameters of the amplifier, exciter
and antennas via RCU and/or PC as described in the TECHNICAL SUPPLEMENT.
zPassword protection against unauthorized access to the amplifier can be selectively enabled. In
addition, the amplifier can be shipped with 10 meters and 12 meters capability disabled as required by
the FCC for US users. Contact your dealer about the way of enabling.
zAll functions are accessible from a PC via serial port connection. Also, local networking capability
exists for more than one set of amplifier / antenna units working in a system. DOS applications are
available on request.
1-5. Safety Considerations, Explicit Definitions
The ACOM2000A Automatic HF Linear Amplifier is a Safety Class I unit, i.e. the third grounding lead of
its mains cord (which is colored yellow with two green stripes) and the ground stud on the rear panel
of the amplifier, marked GND, both 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

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and electromagnetic compatibility requirements, as well as FCC regulations.
This operating manual contains information, precautions, indications for cautions and warnings which
must be followed by the user to ensure safe operation and to keep the ACOM2000A in safe operating
condition.
PRECAUTIONS:
The EXPLICIT DEFINITIONS described below apply to this operating manual:
W A R N I N G notes call attention to a procedure which, if not correctly performed, could result in
personal injury, fire hazard or electric shock.
C A U T I O N notes call attention to a procedure which, if not correctly performed, could result in
equipment damage, not only in the amplifier.
N O T E notes call attention to a procedure which, if not correctly performed, could result in
inconvenience only.
W A R N I N G HIGH VOLTAGE!
The amplifier works with high voltages up to 3000V, which is LETHAL! Also,
for your safety, pull the amplifier power plug out of the mains wall outlet
and WAIT AT LEAST 30 minutes EACH TIME BEFORE you remove the
cover of the amplifier. Do not touch any part inside while the amplifier is
open because some residual voltages may still be present.
W A R N I N G HIGH VOLTAGE!
Never allow anyone, ESPECIALLY CHILDREN, to push anything into holes
in the case - this will cause electric shock. NEVER TOUCH AN ANTENNA
during transmission - this may result in an electric shock or burn. NEVER
EXPOSE the amplifier to rain, snow or any liquids. AVOID placing the am-
plifier in excessively dusty environments or in direct sunlight. DO NOT
OBSTRUCT AIR INTAKE (rear panel) and EXHAUST (top cover) areas of
the amplifier. Keep a minimum distance of 10cm (4 inches) to the intake
and 50cm (20 inches) to the exhaust.
W A R N I N G
Do not undertake on your own repairs or changes in hardware or software
of the amplifier in order not to endanger your or other’s health and life and
not to damage the amplifier and the equipment connected with it, not
covered by warranty. The manufacturer is not liable for another’s actions
and responsibility shall be assumed by the doer.
C A U T I O N
To avoid damage (not covered under warranty) read the Installation - Section 2 of
this operating manual carefully. If you have any doubts about the installation, operation
or safety of the amplifier, please consult your dealer.

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2. INSTALLATION
2-1. Unpacking and Initial Inspection
N O T E
Before you start any action on installing the amplifier, thoroughly read through this
manual. First carefully inspect both cardboard cartons and their contents for physical
damage. If damage is noticed, notify your dealer immediately. Delay may infringe
carrier's warranty conditions. Keep all packing for possible future transportation!
In order to take the RCU out of the amplifier, remove the cover by removing all screws except the eight
located in the tube exhaust areas. Remove the plastic tubes holders but keep them for possible
future transportation.
W A R N I N G HIGH VOLTAGE!
Check the HV Crowbar (Fig. 2-1) - it must reliably shorten the HV lead to
the chassis when cover is open.
Take the RCU out and free the compartment for installing the transformer. Carefully inspect the RCU
and the amplifier main components for any possible shipping damage.
N O T E
Check carefully the serial numbers of amplifier and tubes with the Table of Individual
Data (Table 2-1). If you find any discrepancies notify your dealer immediately to
have your warranty information corrected.
AMP s/n
Front tube s/n
Rear tube s/n
Voltage Selector Position
Optional Fan Output Voltage
Table 2-1. ACOM2000A Individual Data
2-2. Line Voltage Selection
C A U T I O N
To avoid damage (not covered under warranty), check carefully if the voltage for
which the amplifier is set corresponds to your mains nominal voltage. Most 120V
and especially 100V domestic mains installations may not withstand the current
consumption and you will have to reduce the output power to about 1000W PEP.
VAC
VDC

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Normally the amplifier is supplied with Voltage Selector set for a nominal mains voltage of 240V. There
might be exceptions in cases of special delivery and then the voltage set is noted in the Table of Individual
Data (Table 2-1). If your mains has a different nominal voltage, it will be necessary for you to contact
your dealer or see the TECHNICAL SUPPLEMENT for details.
2-3. Transformer Installation
C A U T I O N
After installing the transformer, the weight of the unit is about 35kg, which should
preferably be handled by two persons. An assistant may be needed to hold the
amplifier steady during transformer installation.
Position the amplifier, with the transformer not yet installed, flat on a table near the place where it will
be used. During the process described below, when the amplifier cover is removed, take care not to
torque or twist the chassis nor let the amplifier stand on edge. Do not lift the unit by only one corner.
Orient the amplifier on the table so that the transformer compartment is in front of you (Fig.2-1):
2).
HV PCB HV Crowbar AC Power Console Mains Connector
HV Connector Motor Voltage Connector SG Voltage Connector
Fig.2-1 Transformer Installation
Take the transformer out of the carton and remove the shipping board. Keep the board together with
the four long bolts and all packing for possible future transportation. For transformer mounting, four
shorter bolts (M8x16mm) are provided in a polyethylene envelope inside the same carton.

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Move the transformer, using its rope sling handle, into the compartment. Take care not to damage the
wiring or components and position the transformer so that the captive nuts are aligned with the
corresponding chassis holes. Make sure that the transformer is centered. The transformer bolts must
be installed NOW for safe operation.
Holding its two sides (front and back) simultaneously, pull the amplifier towards you just far enough that
the two outside transformer captive nuts appear off the table edge. Support the amplifier until your
assistant loosely screws in the two outside transformer-mounting bolts. Pull the amplifier a further
12-13cm (about 5 inches) until the other two captive nuts appear off the table edge. Keep supporting
the amplifier until your assistant loosely screws them in. After checking that the transformer is centered,
tighten all 4 bolts. Now move the amplifier back over the table.
The transformer's Mains Connector plugs into the AC power console (Fig.2-1). The other three
connectors (HV, Motors Voltage & SG Voltage) plug into the HIGH VOLTAGE PCB, clearly seen on top.
Replace the cover and carefully reinstall all screws.
2-4. Connections
The amplifier is now ready to be connected to your station. Connection must be accomplished in the
order described below, before you apply mains voltage to the amplifier.
W A R N I N G
Have in mind that the grounding system may have to withstand currents
over 20A with insignificant voltage drop on it. Therefore it may be necessary
to improve it considerably (to become lower-resistive, i.e. with heavier leads
and lower-resistive ground path). The grounding leads should be at least
8mm2(AWG 8 or SWG 10).
Fig.2-2 Connections
Optional Fan Primary Fuses
d e g f h i a c b

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a) First connect the ground stud of the amplifier (on the rear panel, marked GND) to the station's
grounding system (Fig.2-2).
b) Connect a coaxial cable with a PL-259 plug from the transceiver output to the amplifier rear panel RF
INPUT socket.
C A U T I O N
If this is the first time you will use a high power ampllifier in your station, pay attention
to the coaxial cable type from the amplifier’s output. It must handle the increased
power safely, particularly on the higher frequency bands. We recommend you use
RG213 or better. Check the same about the antenna selector and tuner as well as
the antenna itself (especially multiband trap antennas).
c) Connect a coaxial cable from the amplifier output (on the rear panel, marked RF OUTPUT) with a
PL-259 plug to the antenna selector or tuner or to the antenna for the respective band.
d) Run a cable terminated in a Phono connector from the transceiver socket providing “ground on
transmit” to the amplifier rear panel KEY-IN socket.
N O T E
Your amplifier will not work if KEY-IN is not connected properly.
Transceiver producers give different names to this output and they are for instance TX-GND, SEND,
T/R-LINE, etc. Some transceivers require that “ground on transmit” is implemented via a software
command, or by changing the setting of a switch on the rear panel, or interior of the transceiver. Check
your transceiver’s manual.
e) The KEY-OUT socket on the rear panel provides an extra control signal from the amplifier to the
transceiver. It could be used to improve the transmit/receive switching.
If your transceiver has a suitable input which disables transmission, we recommend that you connect it
with a cable terminated in a Phono connector to the KEY-OUT socket of the amplifier. Transceiver
producers give different names to this input and they are for instance TX-INHIBIT, MUTE, LINEAR,
etc. Check your transceiver’s manual. Consult your dealer or see the TECHNICAL SUPPLEMENT for
details.
If your transceiver has not such an input don’t worry - the amplifier will function normally as well and
then the KEY-OUT may remain unused.
f) Connect the RCU cable to the respective DB-9 type connector on the amplifier rear panel, marked
REMOTE CONTROL, and screw in the knurled screws.
g) The ALC output of the amplifier normally remains unused. In case of need of ALC for your transceiver,
which we do not recommend, you may contact your dealer or see the TECHNICAL SUPPLEMENT.
h) The connector on the rear panel, marked INTERFACE, remains unused until you decide to use the
amplifier with a personal computer or in a local network as described in the TECHNICAL SUPPLEMENT.

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C A U T I O N
Do not connect to the connector, marked INTERFACE a "standard" cable because
this may result in damage in both - amplifier or connected equipment. In order to
use PC, a special cable must be prepared. Contact your dealer or see TECHNICAL
SUPPLEMENT for details.
i) Mains plug and fuses.
W A R N I N G
If your amplifier is only fitted with one mains fuse, it is suitable for 0-220/
240 VAC electricity supplies ONLY (these supplies are standard in the
European Community). Your dealer will check that your amplifier is correctly
fused before it is shipped to you. Customers should check with a qualified
electrician if the amplifier is to be used outside the country in which it was
purchased.
Due to the different standards in different countries, the mains plug is supplied and mounted by the
dealer. He connects to the mains cord end a standard mains plug which meets the Safety Class I units
standard in your country. The ground lead of the amplifier's mains cord is colored yellow with two
green stripes and the blue and brown leads are active. When the amplifier is to be used with only one
mains fuse, it is connected in series with the brown lead which must be the active. If you have any
doubts about the correct way of connecting the wires, consult your dealer.
j) Preparation of wall outlet for the amplifier.
W A R N I N G
Before connecting the amplifier to your mains supply, be sure that the supply
is correctly wired, and is adequate for the current drawn by the amplifier.
Make certain that the grounding lead is connected properly in the wall
outlet for the amplifier.
It is preferable that you use the wall outlet closest to the source. The installation leads should be at least
2.5mm2(AWG 13 or SWG 15). Check if the respective fuses can handle current up to 20A, as well as if
the voltage corresponds to the voltage for which the amplifier is set (S.2-2). If you connect the amplifier
to a different mains outlet, be sure that you check it, too.
Make sure the main Power Switch on the front panel is in OFF position (so that the red strip on the
switch is hidden) and insert amplifier's mains plug into the wall outlet prepared for it. The amplifier
remains switched off.
2-5. Installation of Optional Fan
This fan is not necessary in SSB and CW modes, nor in continuous carrier modes (RTTY, SSTV etc.)
with carrier down times of maximum 15 minutes and a subsequent pause of 3 minutes. For higher
duties the fan is recommended. The auxiliary fan (119x119mm) is supplied as an option with a set of 8
screws, nuts and washers. It may be mounted by the manufacturer on request (Fig. 2.2). Contact your
dealer or see the TECHNICAL SUPPLEMENT for details.

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3. POWER ON, RCU CONTROLS, INDICATORS AND MENUS
C A U T I O N
Before you turn the amplifier on, at least 2 hours should have expired since it was
brought in and unpacked in the room where it will be used. Pay particular attention
when you move it from a very cold into a very warm place - condensation is likely
and this could result in damage to the high voltage circuits. In such a case, wait at
least 4 hours. A similar effect can occur after a rapid warming of the operating room
(for instance after switching on a powerful heater).
C A U T I O N
To avoid damage (not covered under warranty) carefully check that the voltage for
which the amplifier is set corresponds to your mains nominal voltage (see S.2-2 and
table 2-1).
After following all instructions in S.2, you can turn ON the Main power switch on the front panel. The
red LED indicator above it must light and a black inscription "ACOM2000A" (or the distributor's name)
will appear on the RCU LCD (Fig.3-1):
Fig.3-1 Remote Control Unit (RCU)
N O T E
LCD contrast and BEEP level regulators are available on the rear of the RCU. For
adjustment use a small insulated screwdriver.

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In this position only the RCU is operational, while the amplifier itself is still turned off. The control of the
amplifier is structured in two menus - OFF and MAIN, each having several sub-menus :
OFF MENU MAIN MENU
INFO sub-menu AUTO TUNE sub-menu
MAN. TUNE sub-menu
MEASURE sub-menu
SERVICE sub-menu
Erasing USR segments
HELP sub-menu
CLR sub-menu
CALL sub-menu
LOCK sub-menu
DEF sub-menu
POWER ON
S.5 S.4
S.5-1
S.4-1
S.4-2
S.4-3
S.4-4
S.4-5
S.5-2
S.5-3
S.5-4
S.5-5
S.5-6
S.3
Fig.3-2 Menu Structure (see also S.8)
You can proceed in one of two directions:
a) you can enter the OFF menu (see below) or:
b) you can turn on the amplifier and begin the warm-up sequence. After 2.5 minutes you may start
operating the amplifier or you may enter the MAIN menu (see S.4).
We recommend that for the time being you examine partly the functions of the RCU in the OFF menu
and thus acquaint yourself with the basic ideas. The control and indications via the RCU are analogous
in OFF and MAIN menus.
The OFF-menu (see also section 5) consists of six sub-menus, which can be reached by pressing the
(Enter) button:

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INFO sub-menu is shown between square brackets in the illustration above. If you wish to select
another sub-menu, move the brackets in the required direction with the (UP), (DOWN),
(LEFT), and (RIGHT) arrows, so that they enclose the desired item. Press (Enter) to open the
respective sub-menu. For example, by means of the and then you will select CALL sub-menu:
When the edge of the display is reached, future movement in the same direction will cause the brackets
to scroll to the opposite end of the display.
To exit from an item, press the (Escape) button. If you press it repeatedly, you will eventually reach
the OFF or MAIN menu. When that menu is reached, the ESC button becomes inoperative.
The purpose and use of these six sub-menus are described in Section 5, after the description of the
basic functions and use of the amplifier.
4. MAIN MENU, FREQUENCY AND ANTENNA SELECTION
Operation of the amplifier is simplified a great deal due to the high degree of automation. You can start
operation immediately after it is installed. However, to make full use of its possibilities and to fully
configure the amplifier to your local conditions, we recommend you thoroughly read the following
information.
a) In order to turn on the amplifier, while the Main Power Switch is on, press the red button on the
RCU and hold it on for about 1 second. The LCD and all LED indicators will flash for about 2 seconds
and you will hear "TEST" being sent in CW. During this time you can check if all indicators are flashing.
After successfully passing the INITIAL SELFTEST, the LED indicators go out and only the red - POWER,
orange - STB (Standby) indicators and the following inscription on the LCD remain lighted:
(nnn is the number of seconds remaining to readiness for operation)
A 2.5 minutes tube warm-up period follows during which heater and bias voltages are applied. During
this time the amplifier remains in STBY, so you can operate with the transceiver only.
Pressing any button during this period will result in turning the amplifier off and going into OFF-menu.

14
N O T E
When you intend to have a pause in operating, it is better to leave the amplifier in
STBY mode instead of turning it off, using the red colored button. Tube life is
shortened by repeatedly turning on and off the tube heater supply.
N O T E
However, if you unintentionally power-off the amplifier, it is best to switch it on
again immediately. When the pause is short (up to 1 minute) and the cathodes are
still warm, the warm-up period is shortened significantly, which reduces the waiting
time and prolongs the tube's expected life.
After the indicated period expires, all voltages are automatically applied to the tubes in the correct
sequence. At the same time the stepper motors tune the plate circuit to the frequency segment on
which the amplifier was used immediately before last switching it off. You hear "R" being sent in CW and
the MAIN MENU appears on the LCD (see example below):
The display informs you about the current state of the amplifier. The bargraph on the upper line indicates
the Exhaust Air temperature and each bar corresponds to 10 degrees centigrade. On the right-hand
side of the same line there is an indication for OPER and STBY mode.
The whole HF spectrum is split in 250 segments. Segment width increases with frequency and is 25kHz
on 160m, reaching 300kHz on 10m. You can use up to ten different antennas per frequency segment.
This could be very useful with narrow-bandwidth antennas.
The frequency segment on which the amplifier is tuned up (in MHz) is indicated on the left-hand side on
the display lower line. To the right of it is indicated the number of the antenna in use (in the example A1
- first) and next to it the tune type for this frequency segment and this antenna (in the example DEF -
Default or factory programmed). The amplifier may also be user-tuned by means of the AUTO sub-
menu as explained in Section 4-1.
b) If the VSWR of the antenna is acceptable (below 1.5:1), you may start operating the amplifier
immediately after pressing the OPR (Operate) button. The green LED-indicator next to the button
glows and you may transmit. The two LED-bargraphs indicate the power fed into the antenna (forward
power) and the power reflected from it (reflected power). The difference between the two is the real
output power delivered from the amplifier.
If you start transmitting on a frequency different from the indicated segment and the amplifier is in
OPER mode, it automatically senses your operating frequency, selects the corresponding segment, and
tunes up on it. This retuning takes less than 1 second and you are immediately ready to operate on the
new band. Example:

15
In the example, a signal frequency between 3650 and 3700kHz was applied and antenna No 3 was last
used there with tuning done by the user (USR).
NOTE
If in DEF sub-menu (see S.5-6) AUTO ANTENNA CHANGE is OFF, then the antenna
number would not change with frequency and remains No 1.
c) A new frequency segment can be selected in two ways:
zas mentioned above, apply from the transceiver a short duration signal (with the amplifier in OPR
mode) - a single word in SSB or a dot in CW (even at 40 wpm) would be enough;
zmanually, in the MAIN-menu by selecting the desired segment by means of the and buttons.
Then confirm it with .
d) A new antenna number can be selected while in the MAIN-menu. Press the or buttons to
select an antenna number, then confirm it with .
N O T E
If you have stop on a certain segment or antenna, but you do not confirm your
choice within 10 seconds, the display will automatically revert to the previous
segment/antenna.
You will notice that while going through antennas and frequency segments, the inscriptions for antenna
number and type of tune-up are shown in lowercase characters. This means that they are not those for
which the amplifier is currently tuned up. If you pass through the current segment, you will see that
UPPERCASE characters are used. While scanning through the options you can see for which segments
and for which antennas in them you have DEF (default) or USR (pre-programmed by the user). You can
scan through these values without affecting the operation of the amplifier. New settings only take effect
after having been confirmed by using the button.
e) The MAIN-menu consists of four sub-menus which can be selected by pressing the button (see
fig.3-2 and S.8).
The purpose and use of these four sub-menus are described in the next sections 4-1 to 4-5.
f) In order to turn the amplifier off, press the red button on the RCU. If you are not going to use the
amplifier for a long time (more than 30 minutes), it is best to turn off the amplifier using the Main Power
switch (on the main amplifier chassis) as well.

16
4-1. AUTO TUNE sub-menu
a) Let us examine the difference between the two types: DEF- and USR- tunings.
DEFault tuning settings are permanently available in your amplifier memory. They are normally used
when the load VSWR at the input end of the feed line is very low.
Real loads often have VSWR greater than 1.5:1, which usually requires the use of an outboard antenna
tuner. Your amplifier will perform the functions of an automatic antenna tuner for VSWR less than 3:1,
or 2:1 on 160m if you prepare USR (User) tunings. This is a fully automatic procedure of matching the
real load to the optimum tubes load.
User tuning settings are memorized and stored in a nonvolatile memory. They will be retrieved
automatically each time you change the operating frequency or antenna number as described in the
previous section. This will enable you to use the amplifier without an outboard antenna tuner over a
wider frequency range and to change frequencies and antennas faster than would otherwise be possible.
The amplifier is capable of memorizing up to 10 different antenna tunings for each frequency segment.
User tuning settings are identified with the identifiers A1 to A9 and AM, irrespective whether they are
for different antennas or for different environment conditions (for example wet and dry weather on
the same antenna).
N O T E
REFLECTED POWER readings and the measured VSWR depend on the load
impedance only and not on the amplifier tuning. If the impedance is different from
the nominal (50 Ohm pure resistive), the REFLECTED POWER bargraph will always
indicate the reflected power presence (even at actual USR-tuning). The proper USR
tuning will, however, allow you to operate with greater power without distortions
and danger to the amplifier.
The real power in the load is equal to the difference between the FORWARD- and REFLECTED-
bargraph readings. For instance, at indicator reading for FORWARD 1775W, and for REFLECTED 275W,
the real output power is 1500W. At very high VSWR (lack of antenna or shortened antenna), the
FORWARD and REFLECTED readings will be almost equal, while the real output power (the difference
between them) will be practically zero.
The amplifier can operate safely if the following rule is obeyed: "REFLECTED POWER < 500W". Matching
can be assured for loads with VSWR up to 3:1 (for 160m - 2:1). Nevertheless, for some loads matching
is possible even at higher VSWR.
C A U T I O N
Using a feeder of coaxial cable at VSWR > 3:1 on HF bands is not recommended.
At such high values of VSWR, the high voltages, high currents, and heat associated
with line losses, risk permanently damaging the coaxial cable.
Always prefer USR- to DEF-tunings and update them periodically, in particular when you install a new
antenna or when a significant change in the environment occurs (snow, ice, newly appeared or removed
massive objects, power lines etc.) that would cause significant changes in the antenna impedance.

17
b) Procedure for preparation of USR-tunings.
We recommend that you prepare USR-tunings for the center frequencies of the segments, but you can
do them for other preferred frequencies.
N O T E
If you use more than one antenna per segment, it is necessary that you select the
proper antenna number (see S.4d) BEFORE the next step. Otherwise you may
"overwrite" some useful tuning for another antenna number.
To select the AUTO TUNE sub-menu while in the MAIN menu, press ENT twice:
The amplifier will then wait for you to apply between 10 and 20W continuous (CW) signal with the
desired frequency. If you leave the amplifier waiting longer than 40 seconds, then it will automatically
revert to the MAIN menu.
The automatic matching process starts the moment power remains constant within the indicated
boundaries. This is shown by the mark on the lower line which indicates the applied input power and
must be somewhere between the two brackets . The antenna impedance matching
is executed automatically in less than 3 seconds and the following message to the operator appears,
while the letter "S" is being sent in CW:
N O T E
If the KEY-OUT control is used (see S.2-4e), the above message will be skipped.
If for some reason matching cannot be accomplished successfully (for example excessive VSWR or
unstable drive power during tune-up), the process ends up with the choice of DEF-tuning and you will
hear “K” being sent in CW:
After removing drive power, the RCU returns automatically to the MAIN menu with USR or DEF
indicated in the lower right-hand side corner.

18
4-2. MANUAL TUNE sub-menu
C A U T I O N
During manual tune do not apply continuous drive longer than 3 minutes and after
that leave pauses of 1-2 minutes for cooling of the tubes.
If for some reason you prefer to match the antenna impedance manually, you can do it in the MAN.TUNE
sub-menu. The procedure starts as for AUTO TUNE, but you will need to adjust the LOAD and TUNE
settings yourself:
Below the inscriptions TUNE and LOAD are indicated the numbers of the current positions of the
motors which control the respective capacitors. To the left of them there are arrows indicating which
way the automatic procedure would move the motor (they are correct only at drive power of 5 to
50W). When changing the direction of the arrows you will hear a sound signal.
The current output power is shown below Pout on the display.
By means of the and buttons you can increase or decrease the step number of the motor
selected in brackets. With the and buttons you can select which motor is to be controlled or
select STO (store), in order to memorize the tuning done as USR in the nonvolatile memory.
To leave the procedure, remove power and press .
N O T E
If you adhere to the tune-up criteria following the arrow prompts, you will achieve
the same results as AUTO TUNE. Because of this, the MAN.TUNE procedure is
only appropriate if you have tune-up criteria of your own. We recommend you use
the AUTO TUNE procedure instead.
4-3. MEASURE sub-menu
Sub-menu MEASURE can be used for control of the technical state of the amplifier and the parameters
associated with it . The LCD is divided into two equal display areas, and in either you can monitor any
of the 20 parameters provided for measuring, for example TEMP-F and DC-INPUT:
With the and buttons you can select the item to be measured (listed in an alphabetic order),
and with and - which display area. When ENT is pressed, the LCD will give a short description
of the parameter selected. This display will appear on the LCD for 5 seconds.

19
For example, for TEMP-F:
During measuring, the amplifier can be used and controlled in OPR or STBY modes, to transmit and
change the frequency segment and antenna if a new frequency is applied to it. Return to the MAIN -
menu is done by the button.
Follows the list of items which can be measured:
Abbreviation Measurand
BIAS GRID BIAS VOLTAGE
DC-INPUT DC POWER INPUT
DRIVE DRIVE RF POWER
FREQ. LAST FREQUENCY USED
FWD-P LOAD (ANTENNA) FORWARD POWER
FIL-V FILAMENT VOLTAGE
GAIN AMPLIFIER POWER GAIN
HV PLATE HIGH VOLTAGE VALUE
IF-REAR FILAMENT CURRENT - REAR TUBE
I-GRID GRID DC CURRENT
I-PLATE PLATE DC CURRENT
I-SCREEN SCREEN DC CURRENT
MAINS LINE (MAINS) INPUT VOLTAGE
PLATE-RF PLATE RF AMPLITUDE (PEAK VALUE)
RFL-P POWER REFLECTED FROM LOAD (ANTENNA)
SCREEN-V DC SCREEN VOLTAGE
TEMP-F EXHAUST AIRFLOW TEMPERATURE - FRONT TUBE
TEMP-R EXHAUST AIRFLOW TEMPERATURE - REAR TUBE
VSWR LOAD (ANTENNA) VOLTAGE STANDING WAVE RATIO
4-4. SERVICE sub-menu
The sub-menu SERVICE can be selected and used only in STBY mode. It is used for adjustment of the
zero-signal plate current and the optical sensors disks during repair. We recommend this procedure is
carried out only by a trained service technician.
If the amplifier remains in the SERVICE sub-menu for more than 5 minutes without any further RCU
input, it will return automatically to the MAIN menu. For more information see the TECHNICAL
SUPPLEMENT .