TB 9-6625-2124-35
Table 9. Step Attenuator Setting Continued
Test instrument
Receiver system indications (dB)
power level
12 GHz
18 GHz
data entries
Min
Max
Min
Max
-50
-48.0
-52.0
-47.7
-52.3
-60
-57.8
-62.2
-57.5
-62.5
-70
-67.7
-72.3
-67.2
-72.8
(5) Press function keys and enter corresponding data on keyboard as listed in (a)
and (b) below:
(a) CW key, DATA ENTRY 18 GHz.
(b) POWER LEVEL key, DATA ENTRY 0 dBm.
(6) Repeat (3) and (4) above at 18 GHz.
b. Adjustments. No adjustments can be made.
24. AM ON/OFF Ratio and
Square Wave Symmetry
a. Performance Check
(1) Connect spectrum analyzer to RF OUTPUT, using 10 dB attenuator.
(2) Press function keys and enter corresponding data on keyboard as listed in (a)
through (d) below:
(a) INSTR PRESET key.
(b) CW key, DATA ENTRY 1 GHz.
(c) POWER LEVEL key, DATA ENTRY 10 dBm.
(d)
MOD (ON) key.
(3) Adjust spectrum analyzer controls as necessary to display the TI output signal.
(4) Measure AM ON/OFF ratio and square wave symmetry; AM ON/OFF ratio will
be greater than 30 dB and square wave symmetry will be 40/60 percent.
(5) Press CW key and enter data 4 GHz on keyboard. Repeat (3) and (4) above.
b. Adjustments. No adjustments can be made.
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.