‰  NOW 25 WPM  ‰  TEXT IS FROM FEBRUARY 2020  QST  PAGE 43 ‰

REPRESENTS A PERFECT 1 1 SWR.  I ACHIEVED THIS BY EXTENDING THE COAX 0R30
WAVELENGTH AND USING A SHUNT CAPACITOR OF 1,200 PF.  FINDING THE 1 1 SWR
VALUE  THE MEASURED IMPEDANCE IS EXPRESSED AS A SERIES CIRCUIT A RESISTANCE
IN SERIES WITH A REACTANCE.  FOR A SHUNT COMPONENT MATCH, ITS EASIEST TO
THINK IN TERMS OF A PARALLEL CIRCUIT, WHICH PROVIDES MULTIPLE PATHWAYS FOR
CURRENT TO FLOW.  HOWEVER, IMPEDANCE CALCULATIONS GET INTRICATE WHEN
DEALING WITH PARALLEL CIRCUITS.  CONSIDER TWO RESISTORS, RA AND RB.  THE
SERIES RESISTANCE IS SIMPLY RA RB, WHILE THE RESISTANCE OF THE TWO
RESISTORS IN PARALLEL IS 1 1 / RA 1 / RB.  ADDING THE REACTANCE COMPLICATES
THE PARALLEL CALCULATIONS EVEN MORE.  THEREFORE, LETS DIVE BRIEFLY INTO THE
INVERTED WORLD OF ADMITTANCE.  ADMITTANCE IS THE RECIPROCAL OF IMPEDANCE.
TO COMBINE TWO CIRCUIT ELEMENTS IN PARALLEL, WE SIMPLY ADD THEIR ADMITTANCE
VALUES.  WERE BACK TO THE SIMPLICITY OF RA RB.  TO CONVERT MY STARTING
‰  END OF 25 WPM TEXT  ‰  QST DE W1AW  ƒ