Section V
TM 11-6625-2781-14&P-2
ADJUSTMENT PROCEDURES (cont' )
d
5-24. 200 MHz IF Bandpass Adjustment (cont'd)
ANALYZER Control Settings (cont'd)
SCAN WIDTH ................................ ................................ ................................ ................................ ....PER DIVISION
SCAN WIDTH PER DIVISION ................................ ................................ ................................ ...................... 10 MHz
INPUT ATTENUATION................................ ................................ ................................ ................................ .... 10 dB
BASE LINE CLIPPER ................................ ................................ ................................ ................................ ..Max ccw
SCAN TIME PER DIVISION ................................ ................................ ................................ ........ 2 MILLISECONDS
LOG/LINEAR ................................ ................................ ................................ ................................ ..................... LOG
LOG REF LEVEL ................................ ................................ ................................ ................................ ......... -20 dBm
VIDEO FILTER ................................ ................................ ................................ ................................ .............. 10 kHz
SCAN MODE ................................ ................................ ................................ ................................ ....................... INT
SCAN TRIGGER ................................ ................................ ................................ ................................ ............ AUTO
606B:
FREQUENCY ................................ ............. 50 MHz
MODULATION................................ .................. CW
ATTENUATION -dBm ................................ ....... - 30
461A:
GAIN (DB) ................................ .......................... 40
2. Tune the HP 606B Signal Generator for
maximum signal display on the analyzer.
3. Adjust LOG REF LEVEL Vernier for full scale
deflection.
4. The upper bandpass skirt should be at least 30
MHz (+3 graticule line) away from CENTER
FREQUENCY 50 dB down.
Upper Bandpass:
50 dB
5. Set SCAN WIDTH PER DIVISION to 2 MHz;
LOG/LINEAR to LINEAR.
6. Set LINEAR SENSITIVITY controls so that the
Figure 5-5. 200 MHz Bandpass Shape Adjustment:
displayed bandpass amplitude is 7 divisions.
CRT Display
7. Measure total deviation of the bandpass flatness; flatness should be within +0.4 divisions (vertical) over 1
divisions (horizontal) referenced from CENTER FREQUENCY. Compare the display with Figure 5-5.
-0.4 ________+0.4 Div
8. If display flatness is within tolerance, no adjustment is necessary. If not, adjust as in steps 9 through 12.
9. Center AMPL CAL; set LINEAR SENSITIVITY to 1 mV/DIV; LINEAR SENSITIVITY Vernier to 1.
10. Turn all three bandpass adjustments on the A9 assembly marked FILTER fully clockwise. Be careful not to
damage the capacitors.
11. Turn the outer FILTER adjustments, A9A3C6 and A9A3C4 ten turns counterclockwise; turn the center FILTER
adjustment A9A3C5 three turns counterclockwise.
12. Adjust the FILTER adjustments, A9A3C4,5,6 for a bandpass shape as shown in Figure 5-5 while maintaining
amplitude at 7 divisions using GAIN adjust A9A1C8. If sufficient amplitude cannot be obtained with A9A1C8,
change the value of factory selected resistor, A9A1R7 until proper level is achieved.
5-11
