I have a DIY harness running my UA-5 and JB3 via 9.6v rc batteries set up to run in paralle, but I only run 1 battery at a time and usually use the internals on the JB3l. I have one set of wires running into a SIMA SUP-2 for the JB3 and the other set runs to a Ratshack adaptacable for the UA-5. Each set has its own inline fuse holder. I started running a 2amp fuse in each side, but noticed after a few times powering the ua-5 up that the fuse kept poping. So I moved up to a 2.5 amp fuse just for the ua-5 side, and still seem to have the problem. The fuse has never blown while recording but every so often when I try to power up it won't power and when I check the fuse its blown. I couldn't seem to find the max amp draw for the UA-5, but I did not think it was more than 2.5 amps. Should I move up to a bigger fuse still, or is there someother underlying problem that I am missing? Sorry if my lingo here is a little confusing, but any help is greatly appreciated.