This is a homebrew amplifier that runs a pair of 4CX250B or 4X150A tubes. It operates on 110 volts and requires only a radio with 2 - 5 deadkey, no external driver needed. Set up with screen and bias, works as it should. Depending on your radio and antenna system, output for this amplifier is 1000 plus (system set-ups are different and output may vary plus or minus). I will also include 2 new 4X150A tubes along with the 2 good ones that are already installed. Sold as is, no DOAs! Shipping to the lower 48 states only at the expense of the buyer. This ad was posted with the eBay Classifieds mobile app.