‰  NOW 35 WPM  ‰  TEXT IS FROM MARCH 2009 QST  PAGES 35 AND 81  ‰

THE TYPE OF INSULATION USED ON THE RADIOSHACK SPEAKER WIRE ISNT SPECIFIED,
BUT I MADE THE ASSUMPTION THAT IT IS POLYETHYLENE OR A SIMILAR MATERIAL
THIS SEEMED SAFE SINCE MANY PLASTICS HAVE A SIMILAR DIELECTRIC CONSTANT OF
ABOUT 2R3.  IN ADDITION, SINCE THE INSULATION BETWEEN THE CONDUCTORS OF THE
SPEAKER WIRE IS THICKER PERPENDICULAR TO THE PLANE CONTAINING THE TWO WIRES
THAN THE INSULATION FOR 300 TWIN LEAD, IT SEEMED REASONABLE THAT IT MUST
HAVE A GREATER INFLUENCE ON THE CHARACTERISTIC IMPEDANCE SINCE MORE OF THE
FIELD BETWEEN THE CONDUCTORS WILL PASS THROUGH THE INSULATION AND LESS
THROUGH THE AIR.  BASED ON ALL OF THIS I ASSUMED THAT THE ADJUSTMENT FACTOR
FOR THE CHARACTERISTIC IMPEDANCE WOULD PROBABLY BE CLOSER TO 0R65 THAN TO
0R75, SO THE CHARACTERISTIC IMPEDANCE FOR THIS LINE MIGHT BE Z 224 X 0R65
145R6, OR ABOUT 150.  AGAIN, THIS VALUE IS NOT PARTICULARLY IMPORTANT, BUT
KEEP IT IN MIND AND WE WILL USE IT LATER TO ESTIMATE LINE LOSS.  VELOCITY
FACTOR THE VELOCITY FACTOR VF OF THE LINE WAS MEASURED USING THE VA1.  THE
TECHNIQUE INVOLVES SHORTING THE END OF THE LINE, THEN SWEEPING THE
INSTRUMENT OVER A RANGE OF FREQUENCIES TO FIND THE LOWEST IMPEDANCE AT
‰  FROM PAGE 81  ‰
193,533 A B VE7CC 964,626 A C KA1MDQ 20,800 A B W4KAZ 48,090 A B NR9A
143,226 A B K6XX 943,520 A C K3XO 46,926 A B VE3AT 1,930,480 A C VE4YU
141,030 A B K6AM 648,875 A C VY2ZM 2,339,922 A C VE3EJ 1,923,750 A C N6AN
‰  END OF 35 WPM TEXT  ‰  QST DE W1AW  ƒ