This is a LM338 based power supply which is not complicated and easy to build. I am using the supply for a long time, have no problem yet. Only current adjust is missing but I overcome this situation by using an LCD panel ampermeter. There is no PCB for the circuit. I took a 3x16 copper plate and strip the unused areas by a knife. If you want you can use analog meters instead of LCD panels.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]