[Elecraft] K3 inline fuse

[Tom W8JI]

Positive lead fuses are a good idea.

Negative lead fuses never were a good idea unless the radio has a totally 
floating negative buss.

If the negative lead fuse to the radio opens for any reason all the negative 
lead current for the radio will flow through the negative lead of any 
accessories connected to the power supply.

They are a terrible idea for any system with the negative lead common to 
ports in and out of the radio, or to the chassis. You certainly won't catch 
me using one!The negative lead needs to be connected solidly to the power 
supply negative for a multitude of reasons, the most prominent of which is 
if the negative lead fuse to the radio opens you can blow up accessories or 
open ground traces including traces in the radio.

They are not even recommended in vehicles any longer in some countries 
because of the fire and damage hazard they create.

73 Tom

> In both Neg and Pos leads, supply a fuseholder and fuse.  I use the
> "stubby" fuses from Motorola @ 30A, you should use something like
> that.  These are T-rated, meaning they're designed to open with a DC
> load.  Don't use a fuse out of your home's fusebox...