Markers - Promax PRODIG-3 Manual Del Usaurio

USER'S MANUAL. PRODIG-3
The horizontal lines define the signal level, the broken lines being separated a
distance equals to 10 dB. The level of the top line (70 dBµV in previous figure), named
Reference Level, can be altered using the vertical cursors
range of 60 dBµV to 130 dBµV by steps of 10 dB (from 70 dBµV to 130 dBµV in satellite
band).
The signal level for each frequency is displayed vertically, the lower frequencies
appear at the left of the screen and the higher ones at the right. The amplitude of the
lobes is calibrated. In the example in previous figure the noise level is at around
25 dBµV and the lobe with the highest signal level (third from the right) is at 70 dBµV.
The frequency range displayed (called span from hereon) can also be altered
using the horizontal cursors
screen frequency range in Spectrum Analyser mode between Full (the entire band),
500 MHz, 200 MHz, 100 MHz, 50 MHz, 32 MHz, 16 MH and 8 MHz (the latter one only
in terrestrial bands).
A vertical broken line, called marker, appears on the spectrum display to identify
the tuned frequency.
One of the applications of the PRODIG-3 operating as Spectrum Analyser is in
the search for the best orientation and position of the receiving antenna. This is
particularly important in UHF. Because such frequencies are involved, with wavelengths
ranging from 35 cm to 65 cm, if the antenna is shifted only a few centimetres, the
relationship between the picture, chrominance and sound carrier frequencies change,
affecting the quality of the picture in the receiver.
If there is an excess of sound carrier, tearing or 'moiré' may appear on the screen
due to the frequency beats between the sound, chrominance and the picture
frequencies.
If there is a chrominance carrier defect, then the television colour amplifier must
function at maximum gain, which could result in noise appearing all over the television
screen with points of colour that disappear when the saturation control is reduced; in an
extreme case, loss of colour may occur.

5.15.1 Markers

(Only in Spectrum Analyser mode). The marker in red colour indicates the central
frequency or tuning frequency, which can be moved by means of turning the rotary
selector [1] as well in channel as in frequency tuning mode
03/2008
[6] keys. Therefore enables selecting the displayed
[6] keys between a
[24].
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