[Elecraft] K2 mobile power fusing

[Bob Lewis (AA4PB)]

On my Mazda PU the main vehicle grounding stud is very close to the
battery and has a smaller wire going to the battery negative terminal
along with the large wire going to the engine block (all original
factory stuff). I figure that if the wire to the block opened, the
higher resistance of the smaller wire *might* permit some current to
flow via the radio ground when attempting to start the engine. For
that reason, I still include a fuse in the negative lead. I didn't
want to get a ground from elsewhere on the chassis because you never
know how quiet or reliable the ground path will be (experience shows
me that some of the other grounding points can have a good deal of
alternator whine present). I can't think of any disadvantage to using
a fuse in the negative lead since it would only blow if there is a
problem with the vehicle's grounding system.

Some of the newer rigs by the way, take the negative lead straight in
to the PC board (the Alinco DR-135 is an example). If you develop a
grounding problem it would be quite possible to "smoke" the PC board
runs inside the radio.