TB 9-6625-2009-35
17. Bandwidth
a. Performance Check
(1) Position controls as listed in (a) through (g) below:
(a) AMPLITUDE MODE LOG 10 dB/DIV pushbutton pressed.
(b) AMPLITUDE REF LEVEL switch to NORMAL.
(c) INPUT SENSITIVITY switch to -20 dB.
(d) FREQUENCY control to 10.0 kHz.
(e) RESOLUTION BANDWIDTH control to 300 Hz.
(f) FREQ SPAN/DIV control to 50 Hz.
(g) SWEEP TIME/DIV control to .2 SEC.
(2) Press and release DISPLAY CLEAR WRITE pushbutton while adjusting
SWEEP MODE MANUAL VERNIER control for a centered, narrow-spike display.
(3) Adjust calibrator frequency for 10 kHz at 0.1 V output amplitude and repeat (2)
above. Monitor frequency with frequency counter.
(4) Position controls as listed in (a) through (d) below:
(a) FREQUENCY control for a peak indication.
(b) AMPLITUDE MODE LOG 1 dB/DIV pushbutton pressed.
(c) FREQUENCY control for a peak indication of 10 kHz input signal.
(d) CAL 10 kHz control for a full scale 0 (zero) dB display.
(5) Slowly vary SWEEP MODE MANUAL VERNIER control cw until display dot
drops 3 dB in amplitude (1 dB per division).
(6) Press and release DISPLAY CLEAR WRITE pushbutton. This is the upper
3 dB point.
(7) Slowly increase calibrator frequency until dot moves full scale then drops to 3 dB
point again.
(8) Press and release DISPLAY CLEAR WRITE pushbutton. This is the lower
3 dB point. Record frequency counter indication. Recorded frequency less 10 kHz signal
will be between 255 and 345 Hz.
(9) Repeat technique of (2) through (8) above, using settings and indications listed in
