Rolsen LT-30FEP, Руководство по обслуживанию

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9
A D J U S T M E N T
Safety Precautions
1. Never disconnect leads while the TV receiver is on.
2. Don't short any portion of circuits while power is on.
3. The adjustment must be done by the correct appliances. But this is changeable in view of
productivity.
4. Unless otherwise noted, set the line voltage to 230Vac 10%, 50Hz. / 110Vac, 60Hz
Test Equipment required
1. RF signal generator (with pattern generator)
2. Multi meter (volt meter)
3. Oscilloscope
4. LCD Color analyzer
RF AGC (Automatic Gain Control) Adjustment
The RF AGC was aligned at the time of manufacturing for optimum performance over a wide range
conditions. Readjustment of RF AGC should not be necessary unless unusual local conditions exist, such as ;
1) Channel interference in a CATV system.
2) Picture bending and/or color beats, which are unusually due to excessive RF signal input when the
receiver is too close to a transmitting tower or when the receiver is connected to an antenna
distribution system where the RF signal has been amplified. In this case, the input signal should be
attenuated (with pad or filter) to a satisfactory level.
3) Picture noise caused by "broadcast noise" or weak signal. If the broadcast is "clean" and the RF
signal is at least 1mV (60dBu), the picture will be noise free in any area.
Adjusting RF AGC to one end of rotation will usually cause a relatively poor signal to noise ratio; Adjusting to
the other end of rotation will usually cause a degradation of over load capabilities resulting in color beats or
adjacent channel interference.