I built one of those quite awhile ago and at the time it was a great little rig, but with 6 ft cord from the sound source to the transmitter(antennae),3 different sets of batteries and on/off switches it was a pain to operate. As soon as a small reliable remote unit became available I switched to it. With remote units priced $100-$200 it isn't even cost effective to build your own anymore.
AWS