eb104 EB1200 User manual

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User's manual
Transistor linear
HF power amplifier 1200 W
Model EB1200

Introduction
Before using the EB1200 Power Amplifier, carefully read this manual and other
documentation supplied with your amplifier. This will allow you to reduce the ris of failure of
this product.
The EB1200 is a transistor HF linear power amplifier designed for use with amateur
radio stations. Distinctive features of the EB1200 amplifier:
instant readiness for operation;
compact size, light weight;
no need to replace components due to wear;
increased service life;
no high voltage in the high-frequency part;
the ability to automate the control process;
touchscreen 5 "screen with the ability to switch LPF ranges and indication of the
amplifier status
EB1200 Precautions
In order for the power amplifier to function properly, there are a few precautions that must be
followed:
do not operate the amplifier without a proper electrical grounding system;
if possible, organize the radio technical grounding of the radio transmitting
device, which will ensure the most efficient and stable operation of all
equipment of the amateur station, will reduce the level of possible interference
and HF interference;
if the amplifier protection systems are repeatedly triggered, it is necessary to
stop the amplifier until the causes of the emergency shutdown are eliminated.
Multiple tripping of protection systems can damage expensive LDMOS
transistors;
do not tune the matching device installed between the amplifier output and the
antenna with a power exceeding 100 W, i.e. 10% of the maximum output power
of the amplifier;
to wor with digital modes of communication, as well as RTTY, it is necessary
to lower the output power of the amplifier to 500-600 W by reducing the supply
voltage.
Avoid dropping, mechanical impact on the product's casing, foreign objects
falling into it - this may damage the electronic components of the EB1200
power amplifier.
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Functional features of the EB1200 amplifier
The built-in potentiometers in the protection circuit and the BIAS voltage control circuit
are set to the correct position during equipment setup and testing. Spontaneously changing the
position of these potentiometers will lead to the need to readjust the amplifier using precision
measuring instruments.
Before using the power amplifier, you must connect a 50 Ohm dummy load, 1200 W or
a matched antenna to the antenna output connector. No-load operation of the amplifier
negatively affects the operation of the RF output transistors.
For 1200 W output power, the input power level must be no more than 85 W. It is not
recommended to use transmitting devices with a power of more than 100 watts with the
amplifier.
The amplifier is designed for an impedance of 50 ohms. If the antenna-feeder devices
are matched to a resistance of 50 Ohm, and the VSWR in all operating ranges does not exceed
2.0: 1, then the amplifier can wor without additional matching. If the VSWR exceeds 2.0: 1, it
is recommended to use additional matching devices.
An LDMOS transistor is used in the output stage of the power amplifier.
The broadband characteristics of the power amplifier ensure complete readiness for
operation after selecting the operating range, without any additional steps to match the final
stage. The use of a high-linear transistor also made it possible to obtain an IMD3 -36 dbC.
The transmit-receive switching process in the amplifier is provided by the TIANBO relay with a
switching time of 12ms.
The power amplifier is equipped with special high-speed protection circuits. For
example, from exceeding the output power, high VSWR in the antenna, exceeding the drain
current of the output transistors and overheating.
To control the operating parameters of the power amplifier, a 5-inch touch screen is
used, which displays the output power level, SWR value, supply voltage, current, LPF control
mode - automatic / manual, transmission mode, power amplifier temperature.
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Table 1
EB1200 Amplifier Specifications
Frequency band 1,8 – 54МГц (and WARC)
Mode SSB, CW, DIGI, RTTY ect.
Input power 70-85W
Output power 1200W (SSB/CW), 500-600W (DIGI,
RTTY)
Maximum VSWR in the antenna 2.0:1
Power supply +48 … +53V
Current 25-27А
Input impedance 50 Ohm (unbalanced )
Output impedance 50 Ohm (unbalanced )
Output/Input connectors UHF SO-239
Amplifier circuit push-pull, class AB
Output transistor LDMOS
Size 255(h) x 210 x 240 mm
Weight ( g) 4,5
Equipment:
HF linear amplifier EB1200 1 pc
Power wire -
Users manual 1 pc
4

Front Panel Description
1. Roc er switch to turn the power amplifier on and off.
2. Indication and control:
Power output W – output power indicator
WR — VSWR level
Current A – current in amperes
Temperature – amplifier temperature in degrees Celsius
Voltage V – supply voltage Volt
Error HIGH WR – lights up red at the moment the protection is activated for
exceeding the permissible VSWR
Error HIGH PWR - lights up red when the protection is activated for exceeding
the permissible output power
Error HIGH CURRENT - lights up red when the overcurrent protection is
activated
ON AIR - green in transmission mode
160 — 1.8 MHz
80 — 3.5 MHz
40 — 7 MHz
30-20 — 10/14 MHz
17-15 — 18/21 MHz
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12-10 — 24/28 MHz
6 — 50-54 MHz
AUTO – automatic range switching mode when using an external device
(automatic decoder)
Turn the amplifier off and on again to reset the protection circuit.
Rear Panel Description
OUT - RF connector for antenna connection.
CONTROL - connector for power amplifier control signals (band selection, transmission signal).
IN - connector for connecting a coaxial cable from a transceiver.
53V - connector for connecting a 48-53V power supply.
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Control cable connection
Control connector pinouts:
Contact circuit
1 160m, GND connection includes 1.8MHz band filter
2 40м, GND connection includes 7MHzband filter
3 6м, GND connection includes 54MHz band filter
4 15м, GND connection includes 21/18МHz band filter
6 80м, GND connection includes 3.5МHz band filter
8 20м, GND connection includes 14/10МHz band filter
9 10м, GND connection includes 28/24МHz band filter
12, 13 + 13.8 В 1.5А
15 РТТ, connection to the GND enables transmission mode
22 - 25 GND, common wire.
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EB1200 Power Amplifier Protection Circuits
1. Over eat protection.
If the temperature of the aluminum cooling radiator exceeds + 45C, the PWM system
will smoothly increase the fan speed.
When the radiator temperature reaches + 60C, the PTT circuit is bro en and it will be
impossible to turn on the amplifier for transmission, until it cools down to + 50C.
2. Protection against exceeding t e maximum permissible output power.
If the output power level exceeds the permissible threshold, the protection will operate,
which disconnects the + 50V supply from the output transistors. To reset the protection, turn off
the + 13.8V power supply for at least 5 seconds.
3. Hig VSWR protection.
If the VSWR in the load exceeds 2.0: 1, the protection system will operate. To reset the
protection, turn off the + 13.8V power supply for at least 5 seconds. If the protection is
triggered, we recommend chec ing the antenna SWR. If you cannot match the antenna, but it
wor s, use an antenna tuner.
4. Protection against exceeding t e maximum permissible current.
If the current value of the output transistors exceeds the permissible threshold, the
protection will operate, which disconnects the + 50V supply from the output transistors. To reset
the protection, turn off the + 13.8V power supply for at least 5 seconds.
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application
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