Lem ,check also pg 6.10.5 regarding standby power switch.Says there that the battery bus is powered by the hot battery bus,regardless of the battery switch position,when switch is in BAT position.
wow,you flew DC3 in Zaire....That's life!!!....by the way,was this long ago?
A long way to the 737,I guess....I have some ideea,as I flew old,classic ,russian types planes, myself years ago..nice ,needles, aviation times....long way to the magenta line...