NS-1228 A Power Supply, for example

Nissei NS-1228A (28A) Switching Power Supply
Featuring analog meters, the Nissei NS-1228A is a highly reliable, compact, and efficient switching power supply designed specifically to power radio stations, CB transmitters, amplifiers, and other communication devices.
Unlike the basic version, this model features continuous voltage regulation and easy-to-read analog meters.
Thanks to advanced technology, it minimizes interference in the HF and VHF bands, making it an ideal addition to any ham radio workshop.
Two backlit analog gauges: Provide an immediate and accurate overview of the current voltage (V) and current draw (A).
Stepless voltage regulation: The output voltage can be easily adjusted within a range of 9 to 15 V DC using a rotary knob on the front panel.
High performance in a compact design: The power supply can handle a continuous current of 25 A and a short-term peak of up to 28 A.
Clean, interference-free output: Low ripple and noise (up to 0.3%) ensure stable operation of sensitive radio equipment without unwanted RF noise.
Comprehensive electronic protection: Integrated protection circuits against short circuits, overloads, and overvoltage protect both the power supply and the connected radio.
Intelligent cooling: The built-in fan automatically adjusts its speed based on the power supply’s current load, ensuring quiet operation during normal use.

Technical Specifications:
Input voltage 110 V / 230 V AC
Output voltage 9.0 – 15.0 V DC (adjustable)
Continuous current: 25 A Peak current (max.): 28 A
Ripple and noise: < 0.3% (Peak-to-Peak)
Meters: 2x backlit analog meters (voltmeter + ammeter)
Cooling: Automatically controlled fan
Dimensions: 170 x 145 x 110 mm
Weight: approx. 1.8 kg