what you need to power both the jb3 and a UA5 together is a voltage regulator box. You can put one together on your own for about $20ish in parts from radio shack, or get a nice one from Todd R. You'll also need a battery source. Most people use the "walmart" battery which, in most cases, is a 9v litium Ion battery designed to power portable dvd batteries. You can get them on ebay fairly cheap. Do a search for "esa dvd battery" or "memorex dvd battery" or "initial dvd battery" and you'll likely come up with some sources. This has been discussed at length in other threads. the
button is your friend.