TB 9-6625-2179-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Modulation Meter, Marconi Instruments, Model 2305. TM 11-6625-3146-
14 was used as the prime data source 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 3
hours, using the microwave 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
Range: 10 MHz
Accuracy: 0.5ppm after 5 min warm-up
Frequency measurement
Range: 500 kHz to 2.0 GHz
AM measurement
Range: 0 to 95%
Accuracy:1 1% rdg LSD at 1 kHz modulation frequency
Range: 0 to 500 kHz deviation2
FM measurement
Accuracy:1 0.5% rdg 1 LSD at 1 kHz
deviation) 1% <5 kHz deviation
Range: +10 to +30 dBm3
Input power
Accuracy: 1 dBm
measurement
Input sensitivity
Range: 25 dBm (500 kHz to 500 MHz)
23 dBm (500 MHz to 1 GHz)
18 dBm (1 to 1.5 GHz)
15 dBm (1.5 to 2.0 GHz)
Flat filters
Range: 65 to 250 Hz
30 Hz to 50 kHz
10 Hz to 300 kHz
Accuracy: 0.1 dB
3 dB filters
Range: 50 Hz to 15 kHz
300 Hz to 3.4 kHz
Accuracy: 0.5 dB
to 3%.
1Calibrated
2Calibrated
to 400 kHz deviation.
3Calibrated to + 10 dBm.