The Spectrum Application (RF Measurements)
R&S
®
FPL1000
111
User Manual 1178.3370.02 ─ 09
4. Set the sweep time to
2.5
ms
.
5. Set the reference level to
6
dBm
and the display range to linear ([AMPT] > "Scale
Config" > "Scaling": "Linear Percent").
6. Define triggering in response to the AF signal using the video trigger to produce a
static image.
a) Press the [TRIG] key.
b) Select "Video".
c) Set the "Trg/Gate Level" to
50%
.
The trigger level is displayed as a horizontal line across the entire measurement
diagram. The R&S
FPL1000 displays the 1
kHz AF signal as a static image in zero
span.
Figure 7-12: Measurement of the AF signal of a carrier that is AM-modulated with 1 kHz
7. Activate the internal AM demodulator to output the audio signal.
a) Press the [MKR FUNC] key.
b) Select "Marker Demodulation".
The R&S
FPL1000 automatically switches on the AM audio demodulator. A
1
kHz tone can be heard over headset (via the headphones connector). If nec-
essary, use the volume control to turn up the volume.
7.2.1.6
Measurement Examples in Zero Span
For radio transmission systems that use the TDMA method (for example, GSM), trans-
mission quality is determined not only by spectral characteristics but also by character-
istics in zero span. A timeslot is assigned to each user since several users share the
same frequency. Smooth operation is ensured only if all users adhere exactly to their
assigned timeslots.
Measurements and Results
