A 600W broadband HF/6m amplifier using affordable LDMOS devices - 2x MRF300 @ 48V

600W HF/6m linear amplifier using rugged MRF300 transistors - NXP Homebrew RF Design Challenge entry. Home page for the project: https://qrpblog.com/a600-hf-6m-600w-ldmos-amplifier/ A few performance figures for the A600: - coverage from 1.8MHz to 54MHz and more - P1dB output power between 580W and 750W depending on band - over 20dB large signal gain, flatness around 1dB - high efficiency (min 57%, max 73% at P1dB depending on band) - stable clean bias with thermal tracking - power supply: 48V, 18A typical, 20A max - advanced thermal design using a liquid metal alloy and copper heat spreader - multiple onboard sensors accesibile via the diagnostic header provide measurements for PA supply voltage, PA instantaneous current draw, heatsink temperature, output power and output mismatch - bias voltage can be disabled via a control line, to save power when not transmitting - onboard connectors for separate low pass filter bank - compact size 190x100x80mm (including heatsink but excluding fans) PCBs were manufactured by PCBway. Have a look, as they offer excellent service: https://www.pcbway.com/