The AMECO Model TPA Tunable Preamp Antenna RF Preamplifier is a versatile and reliable piece of equipment designed for ham radio transceivers. With adjustable gain and a preamp bypass switch. Made in the United States by AMECO. It is powered by an after market 12V DC source. This unit powers on however I am not a radio expert and do not know how to test it. This came from a lot I had purchased from an estate sale of items that were from someone who once did ham or amateur radio. It is in good looking used condition. Sold AS IS Bx