Test Report pages 21 through 25

FCC ID: CB2SAHL3

Test Report

Download: PDF
FCCID_83269

Test report #09800271F FCC 15.231 for VC4968 FCC ID: CB2SAHL3 Tested December 22, 1999 Calculation of Field Strength of Tuning Pulses: [15.231(b)], 15.31(c)] The tuning pulses are generated each time the VC4968 is activated. The tuning pulse sequence is: During the first 100mSec of activation two pulses of a ‘coarse’ tune. During the second 100mSec of activation are nine pulses of a ‘fine’ tune. At approximately 200mSec after activation the encoded transmission begins. The signal levels of the tuning pulses were maximized by maximizing the signal levels of the pulse modulated transmission. The antenna height and turntable azimuth for maximum emission levels were adjusted while measuring the field strength of the pulse modulated transmissions. A typical tuning pulse sequence is presented in this figure below. To determine level of the tuning pulses for comparison to the limits, the following procedure was used. MEASUREMENT PROCEDURE: 1. The EUT was trained to each of the three test frequencies at 30% duty cycle of the 500Hz modulating pulse. 2. The HP8456A EMI Receiver was adjusted to a fundamental frequency and set at 0Hz span, with 1MHz IF Bandwidth. 3. The trigger level was adjusted to capture the pulses of interest. 4. The EUT was activated and a single trace recorded on the Receiver in order to capture the tuning pulses. 5. The captured trace was digitally stored. The stored data points (400 data points for a full screen trace) were then used in calculations to determine the levels of the pulses. AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 83269 Exhibit K: Page 21 of 31

Test report #09800271F FCC 15.231 for VC4968 FCC ID: CB2SAHL3 Tested December 22, 1999 CALCULATION OF THE FIELD STRENGTH OF THE TUNING PULSES.[ 15.35(c) ] Pursuant to 47 CFR 15.35(c), the field strength is determined by averaging over ONE complete pulse train up to 100mSec, including blanking intervals. 1. First was determined the number of data points captured which represented 100mSec span of time. There are 400 data points stored for one complete trace. The scan rate of the HP8546A receiver was set to capture the tuning pulses. This rate was either 200mSec or 250mSec sweep speed. Therefore: Number of data points per 100mSec = 400 / 2 = 200 data points. or = 400 / 2.5 = 160 data points. 2. The AVERAGE field strength level within the 100mSec is then determined by dividing SUM of the levels (uV/m) of all data points by the number of data points. Formula 3: Average Field Intensity 200 Avg. F.I. = (1/200) * (Leveln)uV/m n=1 or 160 Avg. F.I. = (1/160) * (Leveln)uV/m n=1 The charts that follow are the reproduction of the coarse tune pulse traces using number of data points representing 100mSec sweep time from the screen display of the HP8546A EMI receiver. C o a r s e T u n e P u ls e s , 2 8 8 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 1 0 0 .0 1 1 0 .0 1 2 0 .0 1 3 0 .0 1 4 0 .0 1 5 0 .0 1 6 0 .0 1 7 0 .0 1 8 0 .0 1 9 0 .0 2 0 0 .0 m S ec AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 83269 Exhibit K: Page 22 of 31

Test report #09800271F FCC 15.231 for VC4968 FCC ID: CB2SAHL3 Tested December 22, 1999 C o a r s e T u n e P u ls e s , 3 1 0 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 1 0 0 .0 1 1 0 .0 1 2 0 .0 1 3 0 .0 1 4 0 .0 1 5 0 .0 1 6 0 .0 1 7 0 .0 1 8 0 .0 1 9 0 .0 2 0 0 .0 m S ec C o a r s e T u n e P u ls e s , 4 1 8 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 100 110 120 130 140 150 160 170 180 190 200 m Sec AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 83269 Exhibit K: Page 23 of 31

Test report #09800271F FCC 15.231 for VC4968 FCC ID: CB2SAHL3 Tested December 22, 1999 F in e T u n e P u ls e s , 2 8 8 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 9 0 .0 1 0 0 .0 1 1 0 .0 1 2 0 .0 1 3 0 .0 1 4 0 .0 1 5 0 .0 1 6 0 .0 1 7 0 .0 1 8 0 .0 1 9 0 .0 m S ec F in e T u n e P u ls e s , 3 1 0 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 65 75 85 95 105 115 125 135 145 155 165 m Sec AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 83269 Exhibit K: Page 24 of 31

Test report #09800271F FCC 15.231 for VC4968 FCC ID: CB2SAHL3 Tested December 22, 1999 F in e T u n e P u ls e s , 4 1 8 M H z fu n d a m e n ta l L in e a r S c a le 2 5 0 0 0 .0 0 2 0 0 0 0 .0 0 1 5 0 0 0 .0 0 Peak uV/m 1 0 0 0 0 .0 0 5 0 0 0 .0 0 0 .0 0 95 105 115 125 135 145 155 165 175 185 195 m Sec The raw data used in calculating the average field intensity of the tuning pulses are presented in the Appendix of this test report. COARSE TUNE PULSES, Calculated average over 100mSec TX SUM of the levels of all data Number of Data points Average LIMIT MARGIN Freq. points in 100mSec span in 100mSec span SUM/N (MHz) (uV/m) N (uV/m) (uV/m) (dB) 288 341,708 200 1708 4917 9.2 310 420,0414 200 2102 5833 8.9 418 800,078 200 4000 10333 8.2 FINE TUNE PULSES, Calculated average over 100mSec TX SUM of the levels of all data Number of Data points Average LIMIT MARGIN Freq. points in 100mSec span in 100mSec span SUM/N (MHz) (uV/m) N (uV/m) (uV/m) (dB) 288 130,604 200 653 4917 17.5 310 142,252 200 711 5833 18.3 418 210,380 160 1315 10333 17.9 AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 83269 Exhibit K: Page 25 of 31


Document Created: 2001-04-25 08:24:37
Document Modified: 2001-04-25 08:24:37
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC