HF power amplifier 1000W SD2943 (in frame)
1000W HF MOSFET power amplifier.
Operation frequencies 1.8 – 30 MHz
Operation modes SSB, CW
Input power 29 – 37 W
Output power 1000 W
Power supply 13.8VDC, 50VDC
Drain current max 26 – 29 A
IMD3 (@14 MHz, 800W) - 31 dBc
Size 310 x 235 x 160 mm
Weight 6.2 kG
This amplifier use 4 x VRF2933 modern MOSFET transistors. It is equipped with all protections required for safe operation:
max input power,
max output power,
max drain current,
SWR on output higher than 2.0:1.
It has two levels of air cooling fan speed: normal and forced. Forced mode is engaged when copper heat spreader plate temperature rise above 50*C. If temperature rise above 80*C the PTT line is being disabled. Both thermo sensors has 10*C hysteresis.
Two lines LCD shows the output power in Watts and SWR on output. Second line is output power bar graf.
Protection status LEDs are placed on boards, but could be transferred to the front panel.
Rear side has 2 coaxial connectors (input and antenna) and 25-pin control. The control connector is used to select the LPF bands and has +13.8V, ALC and PTT inputs also.
Power amplifier protection device:
Protection from exceeding the output power of 1200 watts.
Protection against exceeding the maximum drain current of the LDMOS transistor.
Protection against overheating - two thresholds of operation:
when the copper radiator is heated more than + 50С - the accelerated mode of the fan operation is activated to increase the heat removal.
when the copper radiator is heated above + 80 ° C, the protection system trips, breaking the PTT circuit. Transmission is not possible.
Protection against exceeding the SWR more than 2.0: 1. The activation of the SWR protection is independent of the output power level
Protection against false / spontaneous band switching in LPF.
The activated protection channel is indicated by a lit LED on the front panel of the power amplifier. To reset the error, it is necessary to switch off and on again the power supply of 48-53.7 V.
The amplifier is assembled on aluminum frame, easy to place inside the box of suitable size.
The manufacturing time is 2-2,5 weeks.