Table 5. Attenuator performance check.

TB 11-6625-2747-50

b. Adjustments. No adjustments can be made.

(14) Adjust OUTPUT ATTENUATOR control of TI

15. Final Procedure. a. Deenergize and disconnect all

to - 10 db.

test equipment and reinsert TI in case if removed for

(15) Adjust REFERENCE ATTENUATOR control

adjustments.

of receiver for a null as indicated on NULL meter of

b. In accordance with TM 38-750, annotate and

receiver.

affix DA Label 80 (US Army Calibrated Instrument).

(16) ATTENUATION-DB digital readout of

When the TI receives limited or special calibration,

receiver will indicate between 9.8 and 10.2 db.

annotate and affix DA Label 163 (US Army Limited or

(17) Repeat (14) through (16) above for each

Special Calibration). When the TI cannot be adjusted

setting listed in table 5. ATTENUATION-DB digital

within tolerance, annotate and affix DA Form 2417 (US

readout of receiver will be within limits specified in

Army Calibration System Rejected Instrument).

table 5. Repeat signal source as necessary for each TI

setting.

Table 5. Attenuator performance check.

Test instrument

ATTENUATION-DB

OUTPUT ATTEN

digital readout of

settings (DBM)

receiver (db)

Minimum

Maximum

-20

19.6

20.4

-30

29.4

30.6

-40

39.2

40.8

-50

49.0

51.0

-60

58.8

61.2

-70

68.6

71.4

-80

78A*

81.6*

*Excessive noise may make this reading and readings beyond this amount difficult to read. For the purpose of periodic

calibration terminate the test at this reading