TB 9-6625-127-24
dt. Set TI as outlined in (1) through (9) below:
(1) TRIG MODE to NORM.
(2) CTRL mode to AM.
(4) COMPL OUTPUT to off.
(5) DISABLE OUTPUT to off.
(6) FRQ to 15 kHz.
(7) DTY to 50%.
(8) AMP to 16 V.
(9) OFS to 0 V.
du. Set function generator for a 2 kHz sine wave, 4.5 V amplitude, 0 V offset output.
dv. Configure spectrum analyzer to display 15 kHz carrier, sidebands, sideband
harmonics and 2 kHz modulation signal as shown in figure 4.
dw. Adjust spectrum analyzer gain for a 0 dB carrier level.
dx. Adjust function generator amplitude until modulation sidebands are 7 dB down from
carrier.
dy. Set A1R413 (fig. 1) to middle position.
dz. Adjust A1R414 (fig. 1) to minimize the level of 2 kHz modulation signal and its
ea. Set TI AMP to 1 V and adjust spectrum analyzer so carrier level is 0 dB.
eb. Readjust A1R414 (fig. 1) to minimize 2 kHz modulation signal level and its 4 kHz
harmonic. (R)
ec. Repeat steps dt through eb above for best compromise at both TI AMP levels.
ed. Verify at both TI AMP levels that all harmonics of sidebands are at least 42 dB
lower than sidebands (49 dB lower than carrier). Remember to adjust spectrum analyzer
each time TI AMP level is changed, so carrier level is 0 dB.
ee. Repeat steps as listed in (1) through (5) below:
cr through cu
(1)
cw
(2)
da through dc
(3)
df and dg
(4)
ed
(5)
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