If cost is not but weight is an issue, lithium AA work well. I expect that you get at least 10 hrs receive. They do not leak. I used KX3 to locate noise with small loops, with limited success due to poor dieirectivity. If your noise sources are on 80m, the new RDF from RigExpert works very well. Ignacy, NO9E -- Sent from: http://elecraft.365791.n2.nabble.com/