Operating instructions

OPERATING MANUAL 2945A
46882-311D 5-9
Spectrum analyzer
C2585
25 mm
Two turn loop
25 mm diameter
RF INPUT
UUT
Fig. 5-6 RF carrier leakage check
(7) Refer to Results table 5-8 on page 5-33. Connect the test equipment as shown in Fig. 5-6,
with the 50
Ω
load connected to the BNC socket of the UUT.
(8) Set the UUT to [Rx TEST], RF IN/OUT [SELECT] BNC output, [RF Gen],
[LEVEL]
−
40 dBm, [FREQ] 501.9873 MHz.
(9) Tune the Spectrum analyzer to monitor 501.9873 MHz. Set other Spectrum analyzer controls
to allow the display of signals below
−
121 dBm (if using the 2383, this can be set to meter
mode).
(10) Hold the loop 25 mm away from the UUT case and check that the level picked up on the
Spectrum analyzer is less than 0.5
µ
V PD.
(11) To confirm the low residual FM of the UUT, the use of an extremely low-noise FM
demodulator is necessary; this is achieved by using the IFR 2041 Low-noise signal generator
as the local oscillator for the 2305. Connect the test equipment as shown in Fig. 5-7.
UUT
Signal generator
C3362
RF INPUT
BNC
OUTPUT
RF OUTPUT
EXT LO
INPUT
LF
OUTPUT
Modulation meter
DVM
VOLTMETER
INPUT
TERMINALS
Fig. 5-7 Residual FM checks