TB 9-6625-2143-24
13. Frequency Response
a. Performance Check
(1) Set INPUT SENSITIVITY control to 0 dB and RESOLUTION BANDWIDTH
control to 3 Hz.
(2) Connect function/arbitrary generator to TI INPUT using 50
feedthrough termination.
(3) Set function/arbitrary generator output for 15 Hz and + 13.01 dBm (1 V rms).
(4) Adjust FREQUENCY control for indication on frequency display near 15 Hz
and press AFC pushbutton.
(5) Press SCALE LOG l0 dB pushbutton and adjust amplitude VERNIER control
for -5 dB (0 dB to -10 dB scale) TI meter indication.
(6) Release AFC pushbutton.
(7) Set function/arbitrary generator and TI to 50 Hz and press AFC pushbutton. If
TI meter indication is not between -4.6 and -5.4 dB, perform b below.
(8) Repeat technique of (5) and (6) above at 100 and 500 Hz, 1, 2, 5, 10, 20, 30, 40,
and 50 kHz. If TI meter indication is not between -4.6 and -5.4 dB, perform b below.
(9) Set AMPLITUDE REF LEVEL control to -40 dB and INPUT SENSITIVITY
control to +30 dB.
(10) Set function/arbitrary generator for 1 kHz and + 3.01 dBm output.
(11) Release AFC pushbutton.
(12) Adjust FREQUENCY control to 1000 Hz and press AFC pushbutton.
(13) Adjust amplitude VERNIER control for -5 dB meter indication on TI.
(14) Set function/arbitrary generator frequency to 50 kHz.
(15) Release AFC pushbutton.
(16) Adjust FREQUENCY control for indication on frequency display near 50,000 Hz
and press AFC pushbutton. If TI meter indication is not between -4.6 and -5.4 dB, perform
b below.
(17) Repeat technique of (10) through (16) above for each setting listed in table 10.
Table 10. Frequency Response
Test instrument
AMPLITUDE
INPUT
REF LEVEL
SENSITIVITY
-30 dB
+20
dB
-20 dB
+10
dB
0 dB
-10
dB
b. Adjustments
(1) Position controls as listed in (a) through (e) below:
(a) SCALE LOG l0dB pushbutton pressed.
(b) AFC pushbutton released.
(c) AMPLITUDE REF LEVEL control to -20 dB.