MODULATORS   FOR  TV-TRANSMITTERS

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.

Carries out:

• 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.

SPECIFICATIONS

	Image	Sound
Frequency range	20…6C106 Hz	20…14C103 Hz
Modulation type	amplitude	frequency
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