‰  NOW 30 WPM  ‰  TEXT IS FROM DECEMBER 2008 QST  PAGES 38, 39 AND 75  ‰

COMBINATION.  USING THE LOG PERIODIC DESIGN PROGRAM FROM THE 19TH EDITION
OF THE ARRL ANTENNA BOOK, THE TV ANTENNA BOOM LENGTH AND NUMBER OF ELEMENTS
WERE INPUT AS A START ING POINT.  THE PROGRAM FOUND THE ELEMENT LENGTHS
NEEDED FOR A 144 TO 148 MHZ LOG PERIODIC WITH AN 111 INCH LONG BOOM.  THE
ELEMENTS WERE TRIMMED TO LENGTH SEE TABLE 1 WITH AN EXTRA INCH ON EACH SIDE
FOR MARGIN.  I USED AN MFJ 259B ANTENNA ANALYZER TO PLOT THE IMPEDANCE OF
THE ANTENNA.  I COMPARED THE MEASUREMENTS TO THE PROGRAM RESULTS AND FOUND
IT WAS RIGHT ON, SO I TRIMMED OFF THE EXTRA INCHES.  THE DESIGN PROGRAM
INDICATED A SPACING FOR THE TARGET 2 METER ANTENNA OF ABOUT 15R7 INCHES
BETWEEN THE TWO REAR ELEMENTS AND 12R2 INCHES BETWEEN THE TWO FRONT
ELEMENTS.  MOVING THE TV ANTENNA ELEMENTS WOULD BE TIME CONSUMING SO I LEFT
THE SPACING AS IT WAS.  THE TV ANTENNA GENERALLY HAS APPROXIMATELY 12R5
INCHES BETWEEN ELEMENTS 1 THROUGH 5, 17 INCHES BETWEEN ELEMENTS 5 AND 6, 17
INCHES BETWEEN ELEMENTS 6 AND 7 AND 12R5 INCHES BETWEEN ELEMENTS 7 THROUGH
‰  FROM PAGE 75  ‰
1,880 IL W4NPS 422 2 8 1,876 VA Estes Valley ARC W0RP KC0KNU 332 2 41 1,872
CO WA4USN WA4GPS 201 2 70 1,864 SC Big Rapids Area ARC N8OE 331 2 18 1,846
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