The Sharman SM30SWI is a compact 13.8V DC switch-mode power supply built for radio and general communications equipment. It provides a stable fixed output, an illuminated analogue Volt/Amp meter (switchable V or A display), plus a Noise Offset control designed to help reduce switching noise—particularly useful on HF.

Full technical specifications

• Type: Switch Mode (SMPS) DC power supply

• Input voltage: AC 220–230V, 50–60Hz

• Output voltage: 13.8V DC (fixed)

• Output current: 20A continuous / 30A peak

• Voltage regulation: < 2%

• Ripple & noise: 80 mV p-p at rated load

• Metering: Illuminated analogue Volt/Amp meter (switchable V or A)

• Noise control: Noise Offset knob (noise suppression adjustment)

• DC connections: Rear DC output jacks/terminals

• Aux output: Front cigarette lighter socket, up to 10A

• Cooling: Rear fan

• Controls/Indicators: Operating LED, On/Off switch

• Protection: Short-circuit protection, overload protection

• Construction: Robust metal case with rubber feet

• Dimensions (W × H × D): 150 × 75 × 195 mm (excluding protrusions)

• Weight: 1.64 kg (including cable)