TB 6625-2328-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Digital Electronic Counter AN/USM-459B. TM 9-6625-907-12 and
TM 9-6625-907-40 were used as the prime data sources in compiling these instructions.
The equipment being calibrated will be referred to as the TI (test instrument) throughout
this bulletin.
a. Model Variations. None.
b. Time and Technique. The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
2. Forms, Records, and Reports. Forms, records, and reports required for calibration
personnel at all levels are prescribed by TB 750-25.
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Test instrument parameters
Performance specifications
Frequency
Range: Channel 1 and 2: Dc to 225 MHz
Channel 3: 100 MHz to 1.3 GHz
Accuracy: ( Timebase 300 ps/gate time x frequency)
Peak volts
Range: -5.1 to +5.1 V
Accuracy: AC signals: (100 Hz to 30 MHz > 100 mV p-p)
25 mV + 10% of V
DC signals: 25 mV + 2% of V
Sensitivity
Channel 1 and 2: 20 mV rms (-21 dBm): dc to 100 MHz
30 mV rms (-17.5 dBm): 100 to 200 MHz
40 mV rms (-15 dBm): 200 to 225 MHz
Channel 3: -27 dBm: 100 MHz to 1.3 GHz
Timebase
Frequency: 0 MHz
Stability: < 5 x 10-10 per day
Range: -1 ns to 105 s
Time interval
Accuracy: (Timebase x time interval)
trigger level timing error 1.5 ns
Trigger level
Range: -5.125 to +5.125 V
Accuracy: 15 mV + 1% of trigger level reading
EQUIPMENT REQUIREMENTS
4. Equipment Required. Table 2 identifies the specific equipment to be used in this
calibration procedure. This equipment is issued with Secondary Transfer Standards Set,
AN/GSM-286; AN/GSM-287; or AN/GSM-440. Alternate items may be used by the
calibrating activity. The items selected must be verified to perform satisfactorily prior to
use and must bear evidence of current calibration. The equipment must meet or exceed the
minimum use specification listed in table 2.