TB 9-4920-460-24
(28) Toggle MOD LEVEL HI/LO down until TI displays 8 KHz FM. If measuring
receiver indication is not within 2 kHz modulation for the 1000 Tone switch setting,
perform b (64) through (72) below.
(29) Toggle TI MOD LEVEL HI/LO switch to several different levels. If measuring
receiver does not indicate within 2 kHz of TI indication, perform b (64) through (72) below.
(30) Rotate TI FUNCTION switch to 156-174 position. Using keyboard set TI to
160 MHz.
(31) Toggle MOD LEVEL HI/LO down until TI displays 8 KHz FM. If measuring
receiver indication is not within 2 kHz modulation for the 1000 Tone switch setting,
perform b (73) through (81) below.
(32) Toggle TI MOD LEVEL HI/LO switch to several different levels. If measuring
receiver does not indicate within 2 kHz of TI indication, perform b (73) through (81) below.
(33) Rotate TI FUNCTION switch to 225-400 position. Using keyboard set TI to
300 MHz.
(34) Toggle MOD LEVEL HI/LO down until TI displays 8 KHz FM. If measuring
receiver indication is not within 2 kHz modulation for the 1000 Tone switch setting,
perform b (82) through (90) below.
(35) Toggle TI MOD LEVEL HI/LO switch to several different levels. If measuring
receiver does not indicate within 2 kHz of TI indication, perform b (82) through (90) below.
(36) Disconnect equipment setup.
(37) Connect oscilloscope to TI AUDIO OUT port and set oscilloscope to high
resolution.
(38) Set output on TI to 100 mV using the AUDIO LEVEL switch.
(39) Press the TI XMIT MEAS switch.
Signal on oscilloscope will be
100 mV 50 mV.
(40) Set output on TI to 500 mV using the AUDIO LEVEL switch.
(41) Press the TI XMIT MEAS switch.
Signal on oscilloscope will be
500 mV 50 mV.
(42) Set output on TI to 900 mV using the AUDIO LEVEL switch.
(43) Press the TI XMIT MEAS switch.
Signal on oscilloscope will be
900 mV 50 mV.
(44) Disconnect equipment setup.
b. Adjustments
(1) Rotate TI FUNCTION switch to 29-88 position and TONES switch to 1000
position. Using keyboard, set TI to 59 MHz.
(2) Toggle TI MOD LEVEL HI/LO switch until TI displays 70% AM.
(3) Measure the modulation levels at 1000 Hz and 150 Hz. Calculate the correction
coefficient as follows:
AMTx = 70% / Average Actual Readings
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