I needed 3 volts to power my newly acquired memory keyer that keys CW into the propagation beacon. The keyer came stock out of the box running on a 3 volt watch battery and if you use the keyer as it was intended for the battery would last over a year or even longer. My beacon transmits 24/7 and draws current 100% of the time. At first I soldered two AA batteries together (don't try that at home) to get the 3 volts and this worked perfect, but looked like sh** with the wires hanging out from the very small keyer case to the AA cells. A nice battery holder from Radio Shack would look slightly better but the wires still would be hanging out and looking sloppy. I slept on it and the next morning while looking in a few cigar boxes for a connector I seen the answer to my voltage nightmare, It was a USB charging adapter. I really did not know the exact output voltage but the voltmeter was used and it stated it was 4.8 volts. I think these things are rated at 5 volts but this one is slightly shy of that. OK you say, I thought you needed 3 volts ? I wipped out the ol' soldering iron and dug out a resister and diode and in short time they were installed. A nice connector was installed on the case and low and behold my beacon is on the air and even looks good. ..... Listen on 28.299.5