TB 9-6625-2330-24
15. Internal Oscillator
a. Performance Check
(1) Connect TI MODULATION IN/OUT to audio analyzer INPUT HIGH.
(2) Press TI pushbuttons as listed in (a) through (e) below:
(a) FUNCTION-RF ON to off (red light extinguished).
(b) MODULATION/AUX-MOD SOURCE DISP to SOURCE ONE.
(c) FUNCTION-MOD FREQ.
(d) DATA ENTRY- 1 kHz
(e) MODULATION/AUX-MOD ON ONE (red light lit).
(3) Configure audio analyzer to measure distortion.
Audio analyzer distortion
indication will be within limits specified in table 18.
Table 18. Internal Oscillator Distortion.
Audio analyzer
Test instrument
MOD FREQ
distortion indications
(%)
frequency
1 kHz
< 0.2
(4) Disconnect TI MODULATION IN/OUT from audio analyzer INPUT HIGH.
(5) Connect TI MODULATION IN/OUT to audio analyzer INPUT HIGH using 50 Ω
feedthrough termination.
(6) Configure audio analyzer to measure level. Audio analyzer indication will be
within limits specified in table 19.
Table 19. Internal Oscillator Output Voltage.
Audio analyzer level indication
Test instrument
(V rms)
DATA ENTRY
mod frequency setting
Min
Max
1 kHz
0.950
1.050
(7) Disconnect TI MODULATION IN/OUT from audio analyzer INPUT HIGH.
(8) Connect TI MODULATION IN/OUT to frequency counter A input.
(9) Configure frequency counter controls to measure frequency with 50 Ω input.
(10) Set TI FUNCTION-MOD FREQ and DATA ENTRY keys to first frequency
listed in table 20.
(11)Frequency counter indication will be within limits specified for frequency listed
in table 20.
(12) Set TI FUNCTION-MOD FREQ and DATA ENTRY keys to next frequency
listed in table 20.