TB 9-6625-2134-24
(11) Set variable attenuator to 0 dB and adjust signal source amplitude control to
position trace amplitude on top graticule line of crt.
(12) Adjust variable attenuator in 2 dB steps for a total of 16 dB. Trace will decrease
in 2 dB 0.4 dB steps on crt. Record error for each 2 dB step. Maximum cumulative error
should not exceed 1.0 dB over the 16 dB range.
(13) Press VERTICAL DISPLAY LIN pushbutton to on.
(14) Set variable attenuator to 0 dB and adjust signal generator amplitude control to
position trace amplitude to top of graticule line on crt.
(15) Adjust variable attenuator for 6 dB. Trace amplitude will decrease to 4 divisions
0.4 divisions.
(16) Adjust variable attenuator for additional 6 dB. Trace amplitude will decrease to
2 divisions 0.4 divisions.
(17) Adjust variable attenuator for another 6 dB. Trace amplitude will decrease to
1 division 0.4 divisions.
(18) Press VERTICAL DISPLAY 10 dB/DIV pushbutton to on.
b. Adjustments. If an out-of-tolerance condition is noted, perform adjustments listed
in paragraph 8 b above.
13. Amplitude Variation with Change in Resolution Bandwidth
a. Performance Check
(1) Position controls as listed in (a) through (i) below:
(a) FREQUENCY RANGE control to 0 - 1.8 GHz.
(b) FREQUENCY SPAN/DIV control to 20 MHz.
(c) FREQUENCY control to 200 MHz.
(d) RESOLUTION BANDWIDTH to 1 MHz.
(e) VERTICAL DISPLAY 2 dB/DIV pushbutton on.
(f) REFERENCE LEVEL control to -20 dBm.
(g) MIN RF ATTEN control to 0 dB.
(h) PEAK/AVERAGE control to AVERAGE.
(i) VIDEO FILTER WIDE and NARROW pushbutton to off.
(2) Connect CAL OUT to RF INPUT.
(3) Adjust FREQUENCY control to aline second marker to center of crt.
(4) Adjust FREQUENCY SPAN/DIV control to 500 kHz and press REFERENCE
LEVEL FINE pushbutton to on.
(5) Adjust REFERENCE LEVEL control for a signal amplitude of 6 divisions on crt.
to 100 kHz. Signal amplitude will not change more than 0.5 dB on crt.