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Emtron DX - 2 SP
SPECIFICATIONS
Band Coverage
EMTRON DX-2SP covers all Nine amateur bands from 160 through 10
meters including WARC bands at full power.
Modes of Operation
The EMTRON DX-2SP has been designed and built to operate at full
power in any mode such as SSB, CW, AM, FM, RTTY and SSTV, and
with the optional QSK, any other digital mode.
Output Power
This amplifier will comfortably deliver 2000 watts (2500 watts
PEP) continuous carrier ("key down") into your antenna. Its
conservative rating of all components and efficient cooling
system allows effective operation at this power level. With 2500
watts of total plate dissipation, the DX-2 will operate well
below the maximum power rating of the tube.
Drive Power
In order to achieve full output power, an input power of
approximately 30 to 60 watts is required. If your transceiver
delivers more output power, reduce the drive level. Specially
when operating RTTY or any other continuous mode, reduce the
drive level and let your transceiver run "COOL" with less strain
on its output components. EMTRON DX-2SP is comfortable with all
popular transceivers such as KENWOOD, ICOM, YAESU, JRC, TENTEC,
etc.
Tube
The EMTRON DX-2SP operates with one SVETLANA GU-84B tube, in
class AB1. This 2500 watt plate dissipation tube has been
constructed primarily for military communication, this tube is
physically and electrically exceptionally rugged and with
additional sophisticated protection circuitry incorporated in
the DX-2SP, it is almost indestructible.
Tube Protection
The EMTRON DX-2SP has a very sophisticated tube protection
circuitry, designed to protect against excessive plate current,
screen grid current, screen grid voltage, bias voltage,
overdrive, SWR, etc. The tube is also protected from excessive
temperature by continuously monitoring the airflow temperature.
In case of any fault, the amplifier goes automatically into
By-pass mode. A 25 ohm, 50 watt resistor in the B+ circuit and a
MOV in the screen circuit further protects the tube and the
power supply from a possible tube internal flash-over.
Cooling
A lot of attention was given to the design of DX-2SP's cooling
system. A pressurized forced air cooling is achieved with a
rugged temperature controlled two speed 72 CFM blower (turbine)
which effectively cools all critical components of the
amplifier. The blower is positioned in such a way that it
prevents hot air being circulated through the system.
Duty Cycle
The EMTRON DX-2SP amplifier will give its designed full output
of 1500 watts when correctly tuned and loaded. In order to
increase the efficiency, an EBS (Electronic Bias Switch) is
incorporated, and can be disabled if so required. The function
of EBS Switch is well known. The amplifier is turned on ONLY
AND ONLY IF RF drive is present. At all other times, the
amplifier tube is virtually resting.
Automatic Drive Level Circuit(ALC)
The ALC circuit in EMTRON DX-2SP amplifier is not of a
conventional design like in all other amplifiers. The DX-2SP's
ALC Circuit operates only for one reason - to prevent overdrive
and keep the signal clean. While operating the DX-2SP, you could
never get the WAN (Worked All Neighbors) AWARD !! No wonder, the
nice compliments the DX-2SP operators get on the quality of
their signals.
The ALC in the EMTRON DX-2SP senses any slight overdrive (50
micro-amps of grid current), warns you, and if you don't do
anything about it, will cut you off for 2 seconds. The 2 second
cut-off is then repeated until the drive level is being reduced.
This ALC circuit also produces a 0 - 10 V negative-going
voltage, proportional to the grid current, but only when
overdrive is present. The EMTRON DX-2SP can be operated without
connecting your transceiver to the ALC output of the DX-2SP and
you are still guaranteed never to overdrive it. However,
connecting the ALC will prevent the overdrive condition to occur
in the first place, and you will not be cut off.
Power Supply
The power supply of the EMTRON DX-2SP is also unique. It
contains a "SOFT START INRUSH PROTECTION", a top grade heavy
duty transformer, a full bridge rectifier and eight high voltage
filter capacitors of 470 uF/500 volt rating. This gives a total
capacitance in the high voltage section of 58uF and a voltage
rating of 4000 volts. The soft start inrush protection circuit
in the new DX-2SP amplifier is another unique design found in no
other amplifier so far. It is the best soft start system
available today. The phase controlled 20amp TRIAC will turn on
the amplifier using a 3-second ramp function. The electrolytic
capacitors are charged linearly over the 3 second period. This
also affects all other circuit components in a similar manner.
Stress in components, failure and "TRANSFORMER BONG" are
non-existent in the EMTRON DX-2SP. Yet another unique new
design, exclusive to the EMTRON DX-2SP amplifier is its screen
grid power supply. Fully voltage regulated for +ve and -ve
screen currents, combined with very effective current limiting,
not only totally protects the GU-84B tube, but also due to its
wide dynamic range, it keeps the tube static operation
parameters absolutely stable. The protection against excessive
screen current is so good, that we have tested the operation
with full screen voltage, while the plate voltage was absent,
for extended time, without damage to the tube. Needless to say
that there is quite a lot of sophisticated electronics present
in the DX-2SP
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