7
2 TECHNICAL SPECIFICATIONS
FREQUENCY COVERAGE
:
Complete (manually tuned) coverage of the nine HF amateur bands:
1.800 – 2.000 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
: The DX-3SP supports SSB, CW, AM, FM, RTTY and SSTV.
OUTPUT POWER:
Typical 4000 watts carrier or up to 5000 W PEP
DUTY CYCLE:
Suitable for SSB operation.
CW: 4 minutes transmit, 1 minute receive.
AM: 3 minutes transmit, 1 minute receive.
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 includes circuitry to monitor:
•
plate current:
should the plate current exceed a safe value, the amplifier goes to standby for 2 minutes.
The nominal trip plate current is 2.5 A
•
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.
The screen current is limited to about 50 – 60 mA total, for the 2 tubes.
•
temperature:
Should the tube's temperature exceed a specific level, amplifier operation is suspended
until the temperature drops to a safe level.
The cut-off temperature sensor has a nominal value of 110° (230F).
The fan speed control temperature sensor has a nominal value of 80° (176F).
OPERATIONAL PROTECTION
•
Overdrive protection:
Should the DX-3SP be overdriven, a LED warning indicator 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-3SP sense an SWR exceeding 2.6:1, a LED warning indicator will
light up, simultaneously with a 3 second cut off.
