Thanks very much Peter for that information. It certainly helps explain what i have observed on testing. At 1 MHz, which is the lowest frequency for which I could measure the voltages there is indeed virtually no voltage drop in the pathway from the TF 1246 to the point where the "Q Multiplier" meter measures the RF input. However at 50 MHz there is much more drop. The voltage at the TF1245 input socket is about 8 volts which is what would be expected if the internal connection impedance in the TF1245 is as you describe. The voltage at the TF1246 output socket is slightly higher suggesting there is a smaller effect in the interconnection link.
73, Morris VK3DOC
