T/R Bias Relay Board Fully Assembled

Fully assembled by me. Must be used either with L-4b Harbach board or a bias mod must be done to eliminate the 50k resistors in the power supply. Rf out – output coax to output directional coupler B- from bias mod string or L-4b Board Ct – yellow wire green stripe center tap from filament transformer V- blue wire switched side of relay coils from soft start or rca jack or L-4b Board V+ 24 vdc from rectifier or L-4b board Rf in coax from input so-239 Amp in coax going to input circuits Rf out braided lead coming off of tank output network coax Install video https://youtu.be/lrdkjTXIQLo?si=S0aQ1bR6yjRcRAh1 May require soft key interface Install video only no paper instructions