Modulators are intended for carrier frequency formation and TV-signal frequency translation (image and sound) to necessary TV- channel frequency.
Modulators are used in TV-transmitters, cable TV systems, MMDS and other systems of TV-signal transmitting.
- stabilization of sound and image carrier frequencies by the synthesizers based on the thermos-tatted frequency oscillator;
- forming of signal with single side band by the SAW filter;
- stabilization of output signal level;
- indication of video signal absent;
- indication of over modulation of audio signal;
- high amplitude and frequency linearity of the section;
- correction of amplitude non- linearity of power amplifier of the TV-transmitters;
- balanced input for audio signal.
|Frequency range||20…6C106 Hz||20…14C103 Hz|
|Nominal level of input signal||1V(at Rinp=75 Ohms)||0,75V(at Rinp=600 Ohms)|
|Input signal levels range||0,5…1,5 V||0,25…1,75 V|
|Signal/noise ratio||60 dB||60 dB|
|Amplitude frequency characteristics unevenness of video signal||±0,2 dB|
|Output signal to channel intermodulation products ratio||60 dB|
|Non-linearity of carrier frequency:|
|-in VHF range||± 50 Hz|
|-in UHFrange||± 200 Hz|
|Power supply||(220± 20) V|
|Operating temperature range||5…450С|
|HF signal output level at Rloading=50/75 Ohms||0,3…3 V|
MODULATORS FOR TV-TRANSMITTERS