The SW-3B is a tiny HF CW transceiver that was developed for use in portable amateur radio applications. It encompasses three of the most common amateur radio bands: 20 meters, 30 meters, and 40 meters. Power output is around 5 Watts, which is sufficient for handheld HF operation. In some respects comparable to the LNR Mountain Topper series, although the firmware is more comparable to the YouKits HB1B series. When it is receiving, the radio uses less than 40 milliamperes of current. It is the perfect CW QRP radio for use in portable applications like POTA, SOTA, IOTA, and Field Day. The external power interface allows for the connection of a battery or any DC supply between 8 and 15 volts. The power interface includes a polarity protection circuit to ensure that the radio will not be harmed by the external power source. In this video, SW-3B is demonstrated in operation by Richard Newstead, G3CWI. The radio can be ordered at this page.