TB 9-6625-152-24
(64) Move probe connection to TI TP6 (fig. 6).
(65) Adjust C59 and R75 (fig. 6) for best centralization and symmetry (adjustments
interact). Alterations to measuring receiver settings may need to be made to facilitate
making these adjustments.
(66) Press TI resolution bandwidth [300 Hz] key.
(67) Set measuring receiver to -30 dBm reference level, 0.5 dB/div, and 200 Hz span
and adjust C55 (fig. 6) until response is accurately tuned to 10.7 MHz.
(68) Set measuring receiver to -17.5 dBm reference level, 0.5 dB/div, and 100 kHz
span and 10 db attenuation.
(69) Press TI resolution bandwidth [3 MHz] key.
(70) Move probe connection to TI IC4 pin 16 (fig. 6).
(71) Adjust C101 (fig. 6) for maximum level indication on measuring receiver.
Reference level on measuring receiver may need to be adjusted to move signal peak onto
screen.
(72) Record level achieved with TI 3 MHz resolution bandwidth selected and step TI
through 300 kHz, 30 kHz, 3 kHz and 300 Hz filters. Ensure level at IC4 pin 16 (fig. 6) does
not vary more than 1.5 dB from recorded level.
(73) If 300 Hz filter is > 1.5 dB higher than recorded level, increase value of R55
(74) Set signal generator output to 10.7 MHz at -7 dBm.
(75) Set measuring receiver to -20 dBm reference level, 2 dB/div, and 20 db
(76) Move probe connection to TI PLA (fig. 6).
(77) Adjust signal generator output for a -22 dBm measuring receiver indication.
Record signal generator output amplitude indication as REF X.
(78) Set measuring receiver reference level to -5 dB.
(79) Move probe connection to TI TP8 (fig. 6).
(80) Adjust R4 (fig. 6) for a 12 dBm 0.1 dB indication on measuring receiver.
(81) Set signal generator output amplitude to (REF X 70 dB).
(82) Adjust R119 for a -70 dBm TI indication (use TI spectrum analyzer marker
facilities for best results).
(83) Set signal generator output amplitude back to REF X.
(84) Adjust R122 for a 0 dBm TI indication (use TI spectrum analyzer marker
facilities for best results).
(85) Repeat technique of (81) through (84) until both indications are consecutively
correct.
(86) Set TI spectrum analyzer scale to 10 dB/div then step signal generator
amplitude down in 10 dB steps to (REF X 70 dB) noting alignment of signal on TI
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