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).
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
10
