CVM/IF
A/V IF Modulators
 
 

General. This Audio/Video modulator is the basic element for the realization of Compact TV Transmitters, where the CVM/IF is plug-in together with IF-channel converter on a 3U (132 mm) height single rack unit. The Audio/Video are the same of classic VAM modulator.


Digital-quality. The CVM/IF uses a back-porch clamping circuit, combined with a full band linearity corrector it's possible to obtain a perfect video quality with negligible distortions and intermodulations. All this means a superior video quality with only a slight difference compared with digital TV.

Compatible with all standard composite video and audio signals (PAL, NTSC, SECAM).Available for B,G,M,N,I,D,K,K1 and L systems. CVM/IF professional multistandard modulator is designed to produce sound and vision modulated signals at any standard intermediate frequency.

Vestigial sideband SAW filter. For a perfect vestigial sideband modulation an high quality SAW filter is used complying all international standards. This filters outstand for their excellent linear phase and flat pass-band and group-delay characteristics.

Group delay precorrection. TV receiver group delay precorrection is provided for all standards.

White clipper. The white clipper is factory set to guarantee the best modulation quality.

PLL sound carrier. Sound and video intercarrier is synchronized by PLL to video line frequency for maximum stability and negligible intermodulations.

Stereo and dual sound. Available with dual sound facility (optional) for stereo transmissions.

 
   
 
     
 
 
CVM/IF
A/V IF Modulators
 
     
 

General characteristics:
Output frequency IF (depending on video standard)
Output level of video carrier -10 to +5 dBm adjustable
Output frequency stability ± 50 Hz
Output impedance 50 W
Output connector BNC
Harmonic and spurious emissions < -60 dBc
In band intermodulation (3 tone CCIR test) < -62 dBc
Operating temperature range -5 °C to + 45 °C
Ambient humidity max. 90%
DC power supply (optional) 24 V d.c. ±20% -12 vdc, +12 Vd. ± 15%
Power consumption 21 VA

Video characteristics:
Input connector BNC unbalanced
Input impedance . 75 W
Input signal level 1 Vp.p.
Input return loss >30 dB
Differential gain < ± 0.6 %
Differential phase < ± 1°
Amplitude frequency response (in the vision band) < ± 0.5 dB
Group delay frequency response (in the vision band) < ± 20 nS
S/N ratio > 64 dB
2T K factor < 1 %
Luminance non linearity < 0.5 %

Audio Characteristics:
Input connector XLR balanced
Input impedance . 600 W
THD (50 KHz peak deviation at 1 KHz) < 0.4 %
S/N (50 KHz peak deviation at 1 KHz) >= 64 dB
Deviation from preemphasis curve (20 Hz to 15 KHz) ± 0.5 dB

Mechanicals:
Dimensions W 76, D 128, H 310 mm
Weight 1.3 kg

 
 
 
  

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