TB 9-6625-2170-35
14. Residual THD + N
a. Performance Check
(1) Connect oscillator output to TI INPUT + and -.
(2) Connect TI INPUT - to ground terminal.
(3) Position controls as listed in (a) through (c) below:
(a) INPUT RANGE switch to AUTO RANGE.
(b) Distortion range AUTO RANGE pushbutton pressed.
(c) All FILTERS pushbuttons released.
(4) Position oscillator controls as listed in (a) through (d) below:
(a) FREQUENCY Hz for 100 kHz.
(b) OUTPUT LEVEL(dBm) for 0 dBm.
(c) GNDED/FLTG pushbutton released to FLTG.
(d) OUTPUT ON/OFF pushbuttons pressed to ON.
(5) Press TI FUNCTION THD + N pushbutton. If TI indication is not ≤ 0.015 percent,
perform b below.
(6) Position oscillator FREQUENCY Hz controls for settings listed in table 8. If TI
does not indicate within limits specified, perform b below.
Table 8. Residual THD + N
Oscillator
FREQUENCY Hz Test instrument
settings
indications
50 kHz
≤0.015%
20 Hz1
≤0.005%
1 kHz
≤0.005%
20 kHz
≤0.005%
FILTERS 80 kHz LO PASS pushbutton.
1Press
b. Adjustments
(1) Position controls as listed in (a) through (d) below:
(a)
INPUT RANGE switch to 2 V.
(b)
Distortion range 0.2 percent pushbutton pressed.
(c)
FILTERS 80 kHz LO PASS pushbutton pressed.
(d)
All remaining FILTERS pushbuttons released.
(2) Position oscillator FREQUENCY Hz controls for 400 Hz and OUTPUT
LEVEL(dBm) controls for 0 dBm.
