I agree about the PSK-31 power. However, when operating as a mobile station, I frequently have trouble with DX stations copying my signal. I sometimes raise my power, to make the contact, and it doesn't always help. I spoke with the N8XJK battery booster manufacturer, and was told that the booster has its own 40 amp fuse inside. Further, if I have a fuse from the booster to my radio (which I now do), I should probably not use a fuse between the battery and the booster. I'm not sure whether this is a good idea, because it's usually the best practice to have the fuses at the battery. However, if fuses ARE kept at the battery, they probably should be 40 amps, because that's what the booster can pull. This was the basis of my original question.