This design offers a practical solution for HF/low-VHF amplifier output filters, handles 600W and is designed to cover all amateur bands form 160m to 4m. It is a necessary accessory for the 600W HF/VHF LDMOS linear amplifier in order to remove any harmonic products and make the amplifier legal to use on the air. Challenges For […]

For optimal performance, the heatsink should have a thermal resistance of 0.1C/W or better at full fan speed. For the prototype I used ABL Components 180AB1500B, it is available in many countries from RS Components. However, the thin anodised black layer had to be removed for better thermal contact transfer (although it improves heat transfer […]

I have recently made available a new version on the A600 amplifier based on MRF300 LDMOS transistors. Here is the list of changes and improvements that come with v2.0. 1. Redesigned and improved PCB All components are now on the top side, while the bottom side is a continuous ground plane in direct contact with […]

Update: this project is evolving. See this page for the latest version. Kits are available in the shop area. The announcement of the MRF300 and MRF101 transistors by NXP in 2018 has generated quite a spark of interest in the amateur radio community and as soon as I learned about them I wanted to get some […]