ACCEPTANCE TESTING
6-6
Attenuator accuracy
The following test will confirm that the attenuator performs to the published performance
specification. In the event of the receiver/down converter not being available, an alternative
method to functionally test the attenuator is also suggested (see 'Alternative attenuator functional
check' below).
C0121
RF OUTPUT
RF OUTPUT
Sensor
UUT
Signal Generator
Measuring
Receiver
Frequency offset
mode connection
➤
➤
➤
➤
Down
Converter
RF
LO
IF
Fig. 6-2 Attenuator accuracy test set-up
(1) Connect the test equipment as shown in Fig. 6-2.
(2) Set the UUT to
[RF Level]
0 dBm
[Carrier Freq.]
2.5 MHz.
(3) Tune the receiver to 2.5 MHz and measure the RF level.
(4) Set the UUT to
[RF Level]
-6.1 dBm and measure the RF level.
(5) Decrement the output of the UUT in 6 dB steps down to an RF level of -120.1 dBm
measuring the RF level at each step. Check that the measured level is within specification.
(6) Repeat (2) to (5) at the frequencies given in Table 6-3.
(7) Set the local oscillator to +8 dBm at the frequencies indicated in brackets in Table 6-3.
Table 6-3 Attenuator frequency settings
Frequency (MHz)
2050T/1T/2T *2051T/2T
**2052T
2.5
1725 (1662)
2775 (2712)
31
2700 (2637)
4125 (4062)
325
5400
(5337)
1125
1275
*At frequencies above 1300 MHz the down converter will automatically be enabled.
**At frequencies above 2700 MHz it is only necessary to test down to -96.1 dBm (determined by
8902 accuracy).
The frequency of the local oscillator will have to be entered on the receiver followed by the test
frequency. This will automatically set the receiver to the required IF frequency.