GENERAL DESCRIPTION
Quite unique in the world is the new Emtron "BIG GUN", the DX-3 HF Linear Amplifier, specially designed for high power applications, delivering an awesome 3000 watts continuos RF output power (4000 watts PEP). The Emtron DX-3 has all the features of the DX-1 and DX-2, however it comes complete with QSK module as standard.
SPECIFICATIONS
Band Coverage
The Emtron DX-3 covers all nine amateur bands from 160 thru 10 meters including WARC bands at full power.
It utilizes a ceramic high quality 9-position band switch for each amateur band. No band compromises like on many other amplifiers on the market. The LOAD and PLATE tuning employ 6:1 vernier drives for silky smooth tuning.
Modes of Operation
The Emtron DX-3 has been designed and built to operate in any mode such as: SSB, CW, AM, FM, RTTY and SSTV as well as any other digital mode.
Output Power
In order to achieve full power output of 3000 watts continuous carrier, an input power approximately 40 to 60 watts is required. If your transceiver delivers more output power, reduce the drive level.
Specially when operating RTTY or any other coninuous mode,
reduce the drive level and let your transceiver run "COOL" with less strain on its output components. In cases where the drive is too high, the DX-3 will let you know of the overdrive condition by automatically bypassing itself for 2 seconds. This action will be repeated until the drive power is reduced.
The Emtron DX-3 is comfortable with all popular transceivers such as Kenwood, ICOM, Yaesu, JRC, TenTec, etc.
Tube
The Emtron DX-3 operates with one GU-78 tube, in Class AB1 with a plate dissipation of 3000 watts. Constructed primarily for military communication, this tube is physically and electrically exceptional rugged and with additional sophisticated protection circuitry incorporated, the DX-3 is almost indestructible.The GU-78 tube is a compact high slope (35mA/V tetrode) and when operated under normal conditions, will last a very long time.
Tube Protection
The Emtron DX-3 has a very sophisticated tube protection circuitry, designed to protect 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 required airflow temperature. In case of any fault, the amplifier is automatically cut off.
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 the DX-3's cooling system. A pressurized forced air cooling was achieved with a rugged temperature controlled 2-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 re-circulated through the system.
Automatic Drive Level Circuit(ALC)
The ALC circuit in EMTRON DX-3 amplifier is not of a conventional design like in all other amplifiers. The DX-3's ALC Circuit operates only for one reason - to prevent overdrive and keep the signal clean. While operating the DX-3, you could never get the WAN (Worked All Neighbors) AWARD!! No wonder, the nice compliments the DX-3 operators get on the quality of their signals. The ALC in DX-3 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 reduced.
This ALC circuit also produces a 1V - 10V negative going voltage, proportional to the grid current, but only when overdrive is present. The EMTRON DX-3 can be operated without connecting your transceiver to the ALC output of the DX-3 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-3 contains a top grade heavy duty transformer and 2 banks of eight high voltage filter capacitors of 470uF/450 volt rating. This gives a total capacitance in the high voltage section of 116uF and a voltage rating of 3600 volts. A full wave bridge rectifier is utilised. Yet another unique new design, exclusive to the EMTRON DX-3 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 tube, but also due to its wide dynamic range, 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-3. The most important module, containing most of the above unique circuitry is the "controller board" which is connected to all the other modules of the amplifier via a wire loom.
Display
All important parameters such as plate current Ip, plate voltage Ep, output power, reflected power, screen grid current, SWR, overdrive, ready, transmit and fault information is displayed on a sophisticated solid state display panel utilizing LEDs of different colors. No switching of any parameter is required. When tuning or operating the DX-3 amplifier all parameters are displayed instantaneously.
Components
Only the very best components with no compromise are used in EMTRON DX-3 amplifier. All RF components such as band switch, tank coils, chokes, etc. are of high quality silver plating, ceramic bobbin for lower frequencies is also used.
Finish
The finish is of high quality durable baked enamel texture paint and silk screening of a quality not found on any other similar equipment.
Warranty
FOUR YEARS full warranty covers all parts and labour, and limited warranty on tube.
FACTORY DIRECT SALES AND SERVICE
The EMTRON DX-3 is sold factory direct; no "middle man" mark up, you do business with the designers and producers, with people who know the heart of the DX-1b, and they will always be able to give you any technical advice.
So get the biggest bargain in top brand linear amplifiers.Emtron DX-3 is the most technically advanced RF linear amplifier operating on all HF amateur radio bands, developed with quality, reliability, performance and price in mind.
Please select any of the models listed below to see their individual specifications and pictures
