3
2 TECHNICAL SPECIFICATIONS
FREQUENCY COVERAGE: Complete (manually tuned) coverage of the seven HF amateur bands:
1.800 – 1.900 MHz
3.500 – 4.000 MHz
7.000 – 7.500 MHz
14.000 – 14.350 MHz
18.000 – 18.500 MHz
21.000 – 21.500 MHz
TRANSMITTING MODES: Both continuous and low duty cycle modes are supported. That is, the DX-2 supports SSB, CW, AM,
FM, RTTY and SSTV.
OUTPUT POWER: Typical 1500 watts PEP
DRIVE POWER: Nominal 50-60 watts for full rated output.
INPUT IMPEDANCE: Nominal 50 ohm passive impedance, unbalanced. VSWR 1.4:1 or less.
OUTPUT IMPEDANCE: Tuned circuit, nominal 50 ohm load, VSWR maximum 2.6:1 set by protection circuit.
DISTORTION: Third order intermodulation products are more than 35 dB below rated output.
HARMONICS: Harmonic output is better than 47dB below the rated output.
FAULT PROTECTION: The extremely comprehensive fault protection systems include circuitry to monitor:
• plate current: should the plate current exceed a safe value, the amplifier goes to standby mode for 2 minutes.
• screen grid over-current: Absolute tube protection is offered with visual warning and a reduced power level being enabled if
the screen current exceeds a pre-set limit.
• temperature: Should the tube's temperature exceed a specific level, amplifier operation is suspended until the temperature
drops to a safe level.
OPERATIONAL PROTECTION
• Overdrive protection: Should the DX-2 be overdriven, a LED warning indictor will light up when the linearity limit is
reached. If the drive is increased further, a 2 second cut off (by-pass) will follow.
• SWR protection: Should the DX-2 sense a load impedance with SWR exceeding 2.6:1, an LED warning indicator will light
up, simultaneously with a 3 second cut off (by-pass).
METERING: The front panel moving LED display systems indicate:
• plate voltage
• plate current
• output power
• reflected power
• screen grid current
• ready and fault conditions
• overdrive warning
• SWR cut-off indicator
ALC: Negative going, adjustable output level.
EBS: Electronic Bias Switch - automatically switches the standing current (about 0.37 A) to a lower ("pre-bias") value - when there is
no input drive.
PRE-BIAS: A small current will flow in the tube when the amplifier is keyed on, but there is no modulation. This will prevent a harsh
sound at the beginning of each word, when the EBS is activated and the tube goes through a non-linear zone, before reaching the
correct initial bias.
QSK: is an option that makes possible the antenna switching at very fast rate - typically 3ms switching time in each direction.
FACTORY INSTALLED ONLY.
SOFT START: when switched on, the mains power is gradually applied to the transformer, over a period of about 5 seconds, to avoid
the high in-rush current typical for such high loads (transformer “Bang” and filament over-current).
COOLING: the cooling fan has 2 speeds, with electronic temperature control. Most of the time the fan runs at low speed, for reduced
noise.
OPERATING TEMPERATURE: 0 to 40° Celsius
FUSING: Two 20A fast acting fuses on the rear panel
DIMENSIONS: 435mm wide, 190mm high, 465mm deep WEIGHT: 4lkg (90 lb) unpacked
3 UNPACKING
The DX-2 is packed in a heavy duty package easily sufficient to protect the amplifier during transportation, even in case of fairly rough
handling. The weight of the commercially rated mains transformer does mean, however, that dropping the amplifier would without
doubt result in some damage.
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