Do it yourself | Knowledge base — E74BYZ

E70BS 30A 13.8V Linear PSU for Radio 11 minutes read Last updated Oct 18, 2026 DIY 30A 13.8V linear power supply for amateur radio — transformer, regulation, overvoltage protection, Arduino metering, and build gallery by E70BS.
DIY 130 Ah LiFePO4 Battery pack 15 minutes read Last updated Oct 18, 2026 Step-by-step build of a 4S 130 Ah LiFePO4 pack for portable ham radio, camping, and backup power — cells, Daly BMS, enclosure, BOM, and load tests.