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ACCEPTANCE TESTING
6-9
Modulation oscillator
Specification
Frequency range:
0.1 Hz to 500 kHz
Accuracy:
Equal to the frequency standard accuracy
Resolution:
0.1 Hz
Distortion:
Less than 0.1% THD at frequencies up to 20 kHz sine wave mode
Test equipment
Description Minimum
specification Example
Frequency counter
10 Hz to 500 kHz
ETP 535B or
Aeroflex 2440
Audio analyzer
Capable of measuring down to 0.03% THD from
100 Hz to 20 kHz
Rohde & Schwarz
UPA 3
Modulation oscillator frequencies
Test procedures
C0218
LF
OUTPUT
UUT
➤
2440
Counter
A INPUT
!
!
Fig. 6-4 Modulation oscillator frequencies test set-up
(1) Connect the test equipment as shown in Fig. 6-4.
(2) Set the UUT to
[Source Freq: F4]
10 Hz.
(3) Referring to Table 6-5, check that the oscillator frequencies can be selected correctly and are
within specification.
Table 6-5 Modulation oscillator frequencies
Modulation oscillator frequencies
(Hz)
10.00
279,620.20
139,810.10 500,000.00