Operating instructions

ACCEPTANCE TESTING
5-9
Spectral purity
Harmonics, spurious, RF carrier leakage, residual FM
Specification
Carrier range:
400 kHz to 1.05 GHz
Harmonics:
Better than −25 DBE
Spurious signals
Better than −30 dBc
Residual FM
Less than 12 Hz RMS (0.3 to 3.4 kHz)
Test equipment
Description Minimum specification Example
Spectrum analyzer
400 kHz to 3 GHz noise floor better than −127 dBm at
500 MHz
IFR 2383
Low-noise FM
demodulator
Residual FM to be less than 2 Hz up to 1 GHz IFR 2305 +
IFR 2041
C2584
UUT
BNC
SOCKET
Spectrum analyzer
Fig. 5-5 Carrier harmonics & spurious check
(1) Refer to Results table 5-6 on page 5-33. Connect the Spectrum
analyzer to the BNC socket
on t
he UUT, as shown in Fig. 5-5.
(2) Set the UUT to [Rx TEST], RF IN/OUT [SELECT] BNC output, [RF Gen],
[LEVEL] 0 dBm, [FREQ] 0.4 MHz. All modulation and noise measurements should be
switched OFF.
(3) Tune the Spectrum analyzer to view the harmonics shown in the second harmonic and third
harmonic column of Results table 5-6, checki
ng t
hat they are within the above specification.
(4) Repeat steps (2) and (3) for the remaining frequencies shown in the table.
(5) Refer to Results table 5-7 on page 5-33. Set the UUT to [Rx TEST], RF IN/OUT [SELECT]
BNC
output, [RF Gen], [LEVEL] 0 dBm, [ FREQ] 0.4 MHz.
(6) Use the Spectrum analyzer to check that any spurious signals are < −50 dBc. Repeat for
UUT carrier frequencies of 500 MHz and 1000 MHz. Repeat for a UUT carrier frequency of
650 MHz checking that any spurious signals are < −50 dBc.