At resonance, the indicator will be dim or off as the transducer is mainly resistive with negligible reactance. The DC resistance of the load is monitored and drives the leakage indicator. This leakage indicator is green for resistances less than 3 megohms, and red for a resistance less than 10K ohms. Using the TT-2 Connect a transducer to the xducer jack. Turn the power on and rotate the frequency knob until the meter peaks, indicating a resonant point.
Most sonar transducers have three resonant points.
The TT-2 is so sensitive that the pressure of a finger on the transducer face will deflect the meter at only one of the three resonant points. This is normally the operating frequency of the transducer. The impedance is found by rotating the z out control until the meter is in the Zo range. The impedance is indicated by the position of the z out knob. Inc. P.O. Box 15037, Chesapeake, VA 23328.