Last night I set down with my Scout schematics and found they do have the
low drop out LM 2940 in mine, (some 7 plus years old).
Mine does not drift at 12 volts, (and I know of none that do). Down around
11 volts, mine drifted once on a bad battery. (Discharged). That battery
might also have had higher internal impedance due to its age.
Thus, since a number of stages of the Scout operate at regulated 10 volts,
and the other regulated stages operate from a 7805 type chip (5 volt logic),
the lower input limit is probably set by the 10 volt bus regulator at 12
volts DC as indicated in their DC specification in the manual. The 10 volt
regulator must be looking for a 2 volt difference to maintain regulation.
Thanks Jerry for the cross reference to the chip numbers. Guess there is
not much to do since they are using 10 volt regulator. ( I think the K2
uses 8 volts, and thus can operate on internal battery on its discharge
curve.)
73, Stuart K5KVH
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