Alpha 77Sx 77Dx wattmeter board to replace original terminal lug design or missing board. PWB is a new and improved version of original board with respect to circuit and component placement. PWB is 0.062″ thick, double sided with a ground planes. Could be used with other amplifiers or a stand-alone single board forward/reverse power wattmeter. Board is designed to work with 1 mA meter movements. Note: This is an assembled and calibrated board ready to install.