‰  NOW 40 WPM  ‰  TEXT IS FROM DECEMBER 2007 QST  PAGES 48, 49 AND 89  ‰
THE SMITH CHART SHOWN IN FIGURE 3 ONLY CONTAINS THE CIRCLE AND WHATS
INSIDE.  IT IGNORES EVERYTHING OUTSIDE THE CIRCLE BECAUSE OF THE NEGATIVE
RESISTANCE VALUE OF THOSE POINTS.  ORIGINALLY THEY WERE ON THE LEFT SIDE OF
THE GRAPH.  THOSE IMPEDANCES CAN NOT BE 
‰  FROM PAGE 89  ‰
K6DGW 266 1 1 512 SV K9UQN 90 2 1 510 IL KQ6RV 129 2 3 508 SDG NORTH 

VALUES ARE THE RECTANGULAR COORDINATES OF THE IMPEDANCE.  HOLD THAT
THOUGHT.  IN A TRANSMISSION LINE, WHEN A WAVE OF RF VOLTAGE AND CURRENT
ENCOUNTERS AN IMPEDANCE DIFFERENT FROM THE CHARACTERISTIC IMPEDANCE OF THE
TRANSMISSION LINE, Z0, SOME OF THE ENERGY IN THE WAVE IS REFLECTED BACK
ALONG THE LINE.  THE PHASE OF THE VOLTAGE AND CURRENTS MAKING UP THE
REFLECTED WAVE WILL DIFFER FROM THOSE IN THE INCOMING OR INCIDENT WAVE
DEPENDING ON THE VALUE OF THE IMPEDANCE CAUSING THE REFLECTION.  THE
INCIDENT AND REFLECTED VOLTAGE AND CURRENT WAVES COMBINE AT EVERY POINT
ALONG THE LINE.  AT EACH POINT, THE COMBINATION RESULTS IN VOLTAGE AND
CURRENT WITH A PHASE RELATIONSHIP DIFFERENT FROM EITHER THE INCIDENT OR
REFLECTED WAVES.  IT IS AS IF THE SAME ENERGY IN THE LINE HAD BEEN APPLIED
TO AN IMPEDANCE WITH VALUES OF RESISTANCE AND REACTANCE THAT CREATE THE
SAME PHASE RELATIONSHIP.  IF YOU CUT THE LINE AT THAT POINT AND REPLACE THE
SECTION BEYOND THE CUT WITH ACTUAL COMPONENTS CREATING THAT EQUIVALENT
‰  FROM PAGE 89  ‰
VE2HLS 135 2 1 690 QC N3HL 309 2 2 684 EPA W0RIC 317 2 1 684 CO K1GPL 158 2
1 682 STX WA6BOB 158 2 1 682 LAX EASTERN CONNECTICUT ARA K1OQ 174 2 1 678

HANDS ON RADIO EXPERIMENT 59 SMITH CHART FUN I N0AX  THE WAYS AND MEANS OF
TRANSMISSION LINES CAN BE MYSTERIOUS AND HARD TO UNDERSTAND.  IS THE
VENERABLE SMITH CHART A MAGIC TALISMAN OF INSTANT KNOWLEDGE?  NO, BUT IT IS
A WINDOW ON WHATS HAPPENING INSIDE THE LINE, ENABLING A BETTER
UNDERSTANDING OF TRANSMISSION LINE MECHANICS.  SMITH CHART BACKGROUND QST
ARTICLES AND THE WIKIPEDIA WEB PAGES ON THE SMITH CHART EN. WIKIPEDIA.
ORG/ WIKI/ SMITHCHART ARE GOOD REFERENCES WITH DEEPER DISCUSSIONS THAN THIS
COLUMN CAN PROVIDE.  YOU CAN READ THESE ARTICLES FIRST OR USE THEM AS
REFERENCES THROUGHOUT THIS COLUMN.  BEFORE DISCUSSING THE CHART, LETS BACK
UP A STEP.  ALL IMPEDANCES CONSIST OF TWO COMPONENTS, RESISTANCE AND
REACTANCE.  GRAPHICALLY, THESE COMPONENTS ARE REPRESENTED AS A PAIR OF AXES
AT RIGHT ANGLES, AS IN FIGURE 1.  THE HORIZONTAL AXIS REPRESENTS RESISTANCE
POSITIVE TO THE RIGHT OF THE ORIGIN AND NEGATIVE TO THE LEFT.  THE VERTICAL
AXIS REPRESENTS REACTANCE POSITIVE INDUCTIVE ABOVE THE ORIGIN AND NEGATIVE
CAPACITIVE BELOW.  ALL POSSIBLE IMPEDANCES CORRESPOND TO ONE POINT Z ON
THAT GRAPH BASED ON THE VALUES OF RESISTANCE AND REACTANCE.  THOSE TWO
‰  FROM PAGE 89  ‰
218 2 1 808 WWA K2MK 188 2 1 802 SNJ W0QQG 185 2 1 790 VA W2LHL 221 2 1 774
NNJ VE3XK 176 2 1 754 ON W7QN 176 2 1 754 WWA WJ2D 347 2 1 748 NC VE3CX 225
2 4 730 ON N4HAI 245 2 4 712 OH AA8IA 165 2 1 706 OH VY2LI 252 2 2 702 MAR
‰  END OF 40 WPM TEXT  ‰  QST DE W1AW  ƒ