
ACCEPTANCE TESTING
6-A-2
Modulation oscillators
The following tests are for a 2050T, 2051T or 2052T with the 2nd modulation oscillator fitted.
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
IFR 2440
Audio analyzer
Capable of measuring down to 0.03% THD from
100 Hz to 20 kHz
HP 8903B
Rhode & Schwarz
UPA 3
Modulation oscillator frequencies
Test procedures
C0218
LF
OUTPUT
UUT
➤
2440
Counter
A INPUT
!
!
Fig. 6-A-1 Modulation oscillator frequencies test set-up
(1) Connect the test equipment as shown in Fig. 6-A-1.
(2) To enable both the modulation oscillators on the UUT, it will be necessary to carry out the
following procedure:-
Press the following sequence of keys:
[UTIL]
[Mod'n Mode] [Comp]
[SIG GEN]
[Source Freq:]
The frequencies of the first modulation oscillator may now be entered.
(3) Referring to Table 6-A-1, check that the oscillator frequencies can be selected correctly and
are within specification.
(4) To monitor the second modulation oscillator, enter the following:
[FM2] [Select Source] [Select Internal] [Internal F1]
[LF] [Mod2 Source] [SIG GEN] [Source Freq:]
The frequencies of the second modulation may now be entered.
(5) Repeat (3) above.