TB 9-6625-2181-24
b. Annotate and affix DA label/form in accordance with TB 750-25.
CALIBRATION PROCESS FOR GENERAL RADIO,
TYPES 1450-TAR AND 1450-TB
15. Preliminary Instructions
a. The instruction outlined in paragraphs 15 and 16 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by common
name as listed in table 2.
c. Unless otherwise specified, verify the result of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments required to calibrate the TI are included in this procedure. Additional
maintenance information is contained in the manufacturer's manuals for this TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
16. Equipment Setup
WARNING
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance check where applicable.
a. Energize equipment and allow sufficient time for warmup and stabilization.
b. Rotate controls throughout their range several times.
17. Attenuator Accuracy
a. Performance Check
(1) Connect equipment as shown in figure 1.
(2) Set TI DB switches to 0.
(3) Adjust calibrator frequency to 1 kHz and amplitude to 0.0 dBm.
(4) Press REL/dBm pushbutton on true rms voltmeter to establish a 0.0 dBm reference.
(5) Set 1 DB/STEP switch (0.1 dB/STEP switch for General Radio, Type 1450-TB)
to 1.
(6) Adjust calibrator output until true rms voltmeter indicates 0.0 dBm. Calibrator
will indicate between 0.9775 and 1.0225 dBm (.07975 and .12025 dBm for General Radio,
Type 1450-TB).