As per a previous post the jumper is in place between terminals 3 and 4 of TB102. The voltage was measured on the jumper with various signal strengths: 0 uV signal resulted in +.05 V on the jumper, 6.5 uV = 0 V, 10 uV = -0.5 V, 100 uV = -3.5 V, 1000 uV = -6.0 V Does anyone know if these figures are in the ballpark? Mike VE7MMH