‰ NOW 35 WPM ‰ TEXT IS FROM SEPTEMBER 2013 QST PAGE 36‰ AT THE SAME POSITION. THIS HELPED TO MINIMIZE THE LOCAL POTENTIAL DIFFERENCES BETWEEN THE WINDINGS ENSURING THAT CAPACITIVE CURRENTS BETWEEN THE WINDINGS WERE MINIMIZED. THE WINDING SCHEME IS SHOWN IN FIGURE 5. IN PRACTICE 20 PRIMARY TURNS WERE SELECTED FOR EACH TRANSFORMER BECAUSE THESE FITTED CONVENIENTLY ONTO THE CHOSEN TOROIDS. THE NUMBERS OF SECONDARY TURNS FOR THE TWO TRANSFORMERS WERE THEN ADJUSTED MATHEMATICALLY TO ACHIEVE A SUITABLE VALUE FOR THE PARALLELED PRIMARY REFLECTED IMPEDANCES, ALWAYS PRESERVING THE REQUIRED RATIO BETWEEN THE TWO SECONDARIES. THE SETTING OF THE NEUTRALIZING TRIMMERS HAS TO BE DONE WHEN THE SECONDARY IS TERMINATED WITH A RESISTANCE. IN THIS CASE THE LOAD RESISTANCE WAS 100. WHEN EACH PRIMARY IS EXCITED WITH A VOLTAGE AT THE DESIGN FREQUENCY THE SECONDARY VOLTAGE IS OBSERVED. IF A HIGH IMPEDANCE OSCILLOSCOPE IS AVAILABLE, THE PHASE OF THE PRIMARY AND SECONDARY VOLTAGES CAN BE COMPARED AND THE TRIMMER ADJUSTED UNTIL THE PHASE DIFFERENCE IS ZERO. THIS CONDITION ALSO CORRESPONDS TO A MAXIMUM IN THE SECONDARY VOLTAGE, SO THAT AN OBSERVATION OF THIS RF VOLTAGE WITH A SIMPLE DIODE RF PROBE AND A DC VOLTMETER WOULD SUFFICE. ONCE THIS PROCEDURE HAS BEEN CARRIED OUT THE INDIVIDUAL TRANSFORMERS CAN BE CONNECTED TO THE POWER SPLITTER CIRCUIT WITHOUT FURTHER ADJUSTMENT. THE OVERALL DESIGN PROCEDURE LED EVENTUALLY TO A MEASURED ‰ END OF 35 WPM TEXT ‰ QST DE W1AW ƒ