R&S FSL Cable TV Measurements (Option K20)
1300.2519.12 2.83 E-11
Test setup:
Connect the R&S FSL to your CATV network.
It is not possible to work without a channel table. You cannot even enter the TV Analyzer sub menu, if
you have not activated a channel table before. Create a channel table according to you CATV network
(or a subset of your network). This task is described in section Example: Creating a channel table. If
you do not want to create your own channel table, you can use the example channel table from section
Example: Creating a channel table, which is delivered with the Cable TV Measurements option.
Procedure:
1. Press the MENU key.
2. Press the Channel Setup softkey.
3. Select the appropriate channel table and activate it by pressing the Activate softkey.
4. Press the MEAS key.
5. Press the TV Analyzer softkey.
6. Press the Tilt softkey.
7. To restrict the channels to be measured, press the Tilt Setup softkey:
The Tilt Setup dialog box is displayed.
To limit the frequency range, under Span, enter a start and stop frequency. Be sure that at least
one channel's RF frequency is in this range. Otherwise the measurement display will be empty!
To select certain modulation standards for the measurement, under Modulation Standards,
activate the modulation standards to be included in the measurement.
8. To adjust the range of the y–axis, if logarithmic, press the Auto Range softkey.
9. Press the RUN key.
10. Observe the exact levels of different channels by turning the rotary knob.
11. Check your network:
Do all signals of the same type (e.g. all analog TV signals) have similar levels?
You can do this by selecting the modulation standards to measure before the measurement.
Or you can measure all kinds of signals and distinguish different modulation standards after the
measurement by their different colors.
You can measure the amplitude response of the network (or of an amplifier) by looking at the
levels of signals at different frequencies. Prerequisite is either that you measure before and after
the amplifier and compare the results. Or that you know, that the levels are equal at the
transmitter.
Channel Tables and Modulation Standards
Measurements with the Cable TV Measurements option can be speeded up significantly if a channel
table is used. First of all a channel table, sometimes also referred as channel plan, contains the
frequency plan of a cable TV network. Furthermore, for every channel it contains the information about
the service broadcast or the information that the channel is < unused >.
Typically every country has its own regulations concerning the frequency plan, i.e. the channel locations
and the channel widths. Unfortunately the services or programs assigned to this frequency plan differ
from one CATV network to another. For example the CATV network of the city of Munich offers different
programs than Erding which is only about 40 kilometers away. Therefore the Cable TV Measurements
option provides empty channel tables for most countries in the world, where empty means, that all
To Next Page
Loading...
