7
2 TECHNICAL SPECIFICATIONS
FREQUENCY COVERAGE
:
Complete (manually tuned) coverage of the nine HF amateur bands:
1.800 – 1.900 MHz
3.500 – 4.000 MHz
7.000 – 7.500 MHz
10.000 – 10.300 MHz
14.000 – 14.350 MHz
18.000 – 18.500 MHz
21.000 – 21.500 MHz
24.000 – 24.500 MHz
28.500 – 29.990 MHz
TRANSMITTING MODES
: Both continuous and low duty cycle modes are supported. That is, the DX-3
supports SSB, CW, AM, FM, RTTY and SSTV. II
OUTPUT POWER:
Typical 3000 watts carrier or up to 4000 W PEP
DRIVE POWER:
Nominal 60-90 watts for full rated output.
INPUT IMPEDANCE
: Nominal 50 ohm passive impedance, unbalanced. VSWR 1.4:1 or less.
OUTPUT IMPEDANCE
: Nominal 50 ohm passive impedance, unbalanced. VSWR 2.6:1 or less.
DISTORTION:
Third order intermodulation products are more than 35 dB below rated output.
HARMONICS:
Harmonic output is better than 50dB below the rated output.
FAULT PROTECTION
: The comprehensive fault protection system 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.
•
Flash-over:
a 3-stage protection circuit using extremely fast MOV’s protects the screen regulator from
the dangerous plate voltage in case of a flash-over in the tube.
OPERATIONAL PROTECTION
•
Overdrive protection:
Should the DX-3 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-3 sense an SWR exceeding 2.6:1, a LED warning indicator will light
up, simultaneously with a 3 second cut off.
METERING:
The front panel moving LED display systems indicate:
“Moving light” LED indicators:
•
output power
•
reflected power
•
screen grid current
•
plate voltage
•
plate current
