‰  NOW 30 WPM  ‰  TEXT IS FROM MARCH 2009 QST  PAGES 35 AND 81  ‰

SEVERAL POINTS.  THE LOWEST FREQUENCY WILL BE THE FREQUENCY AT WHICH THE
LINE IS A HALF WAVELENGTH, THE NEXT WILL BE TWO HALF WAVELENGTHS, ETC.  THE
VELOCITY FACTOR CAN THEN BE CALCULATED BY THE RATIO OF THE PHYSICAL LINE
LENGTH TO THE VALUE OF A HALF WAVELENGTH IN VACUUM AT THE PARTICULAR
FREQUENCY GIVEN BY THE FORMULA L 492/F, WHERE L IS IN FEET AND F IS IN MHZ.
THE RESULTS FOR MY ROLL OF NO.  278 1385 SPEAKER WIRE NEAR FOUR AMATEUR
BANDS ARE SHOWN IN TABLE 1.  SINCE I PLANNED TO BUILD MY ANTENNAS MOSTLY
FOR THE 20 METER BAND AND ABOVE, I CHOSE TO USE 0R70 AS THE VELOCITY FACTOR
OF THIS LINE.  I COULD JUST AS WELL HAVE SAID THAT I PICKED 0R70 BECAUSE IT
IS A ROUND NUMBER OR BECAUSE IT IS APPROXIMATELY THE AVERAGE OF THE FOUR
READINGS.  I THINK THESE RESULTS ARE AMAZINGLY CONSISTENT CONSIDERING THE
USE OF A CONSUMER GRADE HANDHELD INSTRUMENT.  THERE IS ONLY A 4 VARIATION
IN MEASURED VELOCITY FACTOR OVER A FREQUENCY RANGE OF ABOUT AN ORDER OF
MAGNITUDE.  ATTENUATION THE ATTENUATION OR LINE LOSS WAS ALSO MEASURED
‰  FROM PAGE 81  ‰
607,005 A C K1DG 1,982,916 A C N5DX 1,389,545 A C KE9I 497,484 A C K5NA
1,249,620 A C K1LZ 1,787,478 A C W4AN 1,029,155 A C VE3XN 245,291 A C W5KFT
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