This is a design for a 13.8 V power supply that can charge a sealed lead battery and simultaneously power equipment with a 13.8 V nominal supply voltage. Maximum current is 1.5 A and this can be delivered continuously, even when the output is short-circuited. Output current will be limited further when the regulators run too hot.
A tuned loop is a very effective antenna for medium wave reception in an area with man-made noise. However, using such a loop in close proximity to a laptop computer with an SDR (software-defined radio) is not a good idea because the loop will pick up interference from the computer. Therefore I decided to build a loop antenna with remote tuning by varicaps (varistors if you prefer that term), picking up the idea from T.J. Nelson’s article. That way you can move the loop antenna to a spot further from the computer and possibly a spot with lower interference. Outside is best, so I’ll be aiming to build something that can withstand inclement weather (within reason!).