Technical data

Chapter 4: Specification & Performance Verification
4-24 2400 Series Operation Manual, 33237 Revision A, May 2004
4.4.3.3.1 Narrow Mode FM Accuracy and Maximum Deviation Test
Procedure
1. Connect the output of the UUT to FM discriminator. The output of the discriminator is connected
to the oscilloscope.
2. Connect the function generator to the external FM input of the UUT. Set the function generator
to the following settings:
Rate: 5 kHz
Waveform: Sine wave
Output: 2 Vpp into 50 ohms
3. Set the level of the UUT to +13 dBm, activate the RF output of the UUT and set the external FM
setting of the UUT to the following:
FM State: Off
Mode: Narrow
Sensitivity: 1 MHz/volt
4. Set the UUT frequency that will produce a 0 volt output from the FM discriminator.
5. Adjust the frequency of the UUT ±1 MHz. The output of the discriminator must exceed ±3 divi-
sions on the oscilloscope.
6. Adjust the vertical gain of the oscilloscope so that a 1 MHz frequency change from the zero cross-
ing frequency of the UUT results in a three-division change on the oscilloscope.
7. Set the UUT frequency back to the test frequency and toggle the FM state to ON. Check that the
peaks of the oscilloscope display are within ±0.15 volts of the 3 divisions (±5% Accuracy).
8. Vary the rate of the function generator from DC to 50 kHz and check that the output of the dis-
criminator is within 4 to 8 divisions (3 dB bandwidth) of the oscilloscope.
9. Repeat steps 4 through 8 for the remaining frequency test points.