Radio Shack 21-533 owner manual Fm Page 12 Thursday, August 5, 1999 347 PM

Page 12

21-533.fm Page 12 Thursday, August 5, 1999 3:47 PM

The template shows an imaginary circle around an antenna. The spokes on the template represent imaginary straight lines measured from the center of the circle to 36 points spaced equally around the circle. Each straight line is 25 feet in length. The numbers on the template (1–5) are a guide to show you where to mark the field strength level the meter displays as you measure.

Hint: To help measure a circular path around the antenna, tie a slip knot in a 25-foot piece of rope or strong cord, slide the knot loosely around your antenna, then use the rope as a guide as you walk around the antenna.

Follow these steps to prepare the antenna site.

1.Starting at the antenna, use a compass to find due north. Then walk due north and stop about 15 to 25 feet away from the antenna.

2.Use an object such as a rock or a weighted piece of paper to mark where you are standing.

3.Walk around the antenna in a circle, using more objects to mark 35 more evenly spaced marks on the path.

Hint: You can quickly find the space to leave between each mark by using a calculator. Measure the diameter of the marked circle (from one side of the circle to the other). Then, divide the diameter by 11.46.

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Contents CB/Ham Field-Strength SWR Meter Introduction Contents Connecting the Meter Measuring SWRCalibrating the Meter Measuring SWR Fm Page 6 Thursday, August 5, 1999 347 PM SWR Scales Interpreting SWR Readings Improving SWR Measuring Field Strength HintsPreparing the Antenna Site Fm Page 12 Thursday, August 5, 1999 347 PM Calibrating the METER/ Measuring Field Strength Set CALIBRATION/FS/SWR to CALIBRATION/FS Dot Fm Page 16 Thursday, August 5, 1999 347 PM Using Field Strength Readings to Tune Your Radio and Antenna Fm Page 18 Thursday, August 5, 1999 347 PM Care and Maintenance Fm Page 20 Thursday, August 5, 1999 347 PM Schematic Diagram Specifications Limited Ninety-Day Warranty RadioShack