TB 9-6625-152-24
Table 9. Amplitude Modulation.
Test instrument
Measuring receiver
Indication limit (%)1
(MHz)
Min
Max
10
47.4 (47.4)
52.6 (52.6)
50
47.4 (47.4)
52.6 (52.6)
250
47.4 (47.4)
52.6 (52.6)
500
47.4 (46.4)
52.6 (53.6)
750
47.4 (46.4)
52.6 (53.6)
1000
47.4 (46.4)
52.6 (53.6)
Values in parentheses are for model 2947A.
1
(4) Set TI output to minimum.
b. Adjustments
(1) Press TI HELP SETUP, [Setup], [Calibrate] keys.
NOTE
If the message Locked appears adjacent to the [Calibrate]
key, it must be unlocked before access can be obtained. Press
[Calibrate]. The message ENTRY CODE will appear. Key in
the digits 2, 9, 4, 5, then press the [dBm/ENTER] key. If the
procedure has been carried out correctly the Locked message
will be removed and the [Calibrate] key will now be active.
Press [Calibrate].
(2) Press TI [AM level].
NOTE
When AM LEVEL screen is selected, TI is configured to output
a 144 MHz signal with 70% AM at ~ +8 dBm.
(3) Connect measuring receiver to TI BNC RF output connector.
(4) Configure measuring receiver for AM depth measurement with Peak+ detector,
300 Hz high pass filter and 15 kHz low pass filter.
(5) Use TI [ ], [ ] keys to highlight 0dBr calibration point.
(6) Use TI rotary knob to alter data value until measuring receiver indicates
70.0% AM.
(7) Use TI [ ], [ ] keys to step down to next calibration point in displayed table.
(8) Use TI rotary knob to alter data value until measuring receiver indicates
70.0% AM.
(9) Repeat technique of (7) and (8) above for all remaining calibration points in TI
displayed table.
(10) When all calibration points have been set up with correction factors, press TI
[Return] key and then [Store Cal] key.
(11) Perform paragraph 13 a above.
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