VA
elektronik
Sams elektronik d.o.o. • [email protected] • www.sams.rs
14
Distribution amplifiers
ADJUSTMENT
Video distribution is factory set to (GAIN) 1V p-p ± 5% @ 75% Color Bar test. EQ is set to minimum.
For adjust is used 1m cable.
To adjust the distribution in the system, it is necessary to have:
- Signal generator (a signal which is brought to the input of the distribution)
- Adequate measuring instrument (output signal of the distribution)
- A small flathead screwdriver (for adjusting)
1) Start test “75% Color bar”. Using a measuring instrument, note whether there is a deviation.
Slowly turn the GAIN potentiometer to adjust the signal level at 1V p-p.
2) EQ is the process of adjusting the balance between the levels of different frequencies in the
video signal. Due to the length of the cable, it will weaken the level of higher frequencies. Start
Multiburst test. Using a measuring instrument, note whether there is a deviation. Slowly turn the
EQ potentiometer to ensure consistency across all frequency amplification.
Test 1: 75% Color Bar for GAIN
Test 1: 75% Color Bar
Composite
Test 2: 60% Multiburst for EQ
Test 2: 60% Multiburst
5
Composite
FREQUENCY ATTENUATION
CORRECT EQ
