Application Examples - Televes 5930 Manual De Instrucciones

Noise generator
The noise generator can be powered by an mains
adaptor, or by the meter via an RF cable. In order to
do this simply select the pre-amplifi er powering in
the meter's corresponding menu.
To access the pre-amplifi er powering menu in the
fi eld strength meter, you can follow these steps:
In the terrestrial band:
CONFIG. LNB &
MEASURE PREAMPLIF.
Or, press the fast button
This will open the Powering window:
It is advisable to select the power measurement
in the fi eld meter when working with the noise
generator.

Application examples:

A few applications of the noise generator are
briefl y explained below:
1 .- Checking the condition of a section of the
cable before installing:
By using the noise generator and the fi eld meter
LNB it is possible to check the condition of a section of
the cable before installing it.
- Confi gure the fi eld meter to analyze mode, select
Full Span and select the powering measurement.
- Connect the noise generator to the fi eld meter.
Check that the generated noise spectrum is
nearly fl at. The longer the cable you are going to
check, the bigger the powering produced by the
noise generator should be. A small table with the
recommended minimum powering, depending
on the length of the cable to be checked, is shown
below (the wire T100 -ref.2141 has been used as an
example).
Length of cable in Minimum output powering
metres (T100) of the noise generator
10
25
50
75
100
150
Select the adequate reference level on the meter.
Note down the measurement of the powering in
several frequencies along the terrestrial band, and
then do the same with the satellite band. Likewise
you must take into account the bandwidth and the
resolution fi lter used in the measurement, as the
powering measurements at the input and at the
output should be measured with the minimum
values for these parameters.
In the next example we use the following
frequencies as a reference:
The terrestrial band: 200, 500 e 800 MHz
The satellite band: 1000, 1750, 2150 MHz
The powering measurements for the reference
frequencies are (with BW=8 MHz and RBW=250
KHzW):
16
(dBμV)
43
47
55
62
70
80