Modulator MT-21P (channels 21-69) with power supply
Kód zboží: R871721
Zboží je stáhnuto z nabídky
Modulator view
...and the view after removing the flap covering main part
Top view. Push-buttons "+" and "-" serve to settle output channel, with the left side pot underneath the proper deviation of sound subcarrier is set, and the right lower corner pot sets RF output level of the modulator.
Termination load and mounting screws included
Output level adjustment enables to match the level to other signals within an installation, also concerning other possible connected in series modulators.
50 kHz is the standard modulation assumed for input audio signal of 0,775 V RMS. The adjustment of deviation ensures to level the deviation when an audio signal differs from the norm. The ultimate standard deviation can be obtained within range of 0,150-0,775 V . Correct adjustment is essential for equal volume levels on individual TV channels.
 |  |  |
| During switching on key "-" is being pressed | During switching on key "+" is being pressed | During switching on both keys "-" and "+" are being pressed |
| Possibility of setting sound standard 6.5/5.5 MHz | Possibility of setting video modulation factor +/-6% at 2% intervals | Possibility of setting output frequency +/-2.5MHz at 250kHz intervals |
The standard depth of video modulation is 75%, however sometimes it can be useful to change it a little, e.g. when a source generates alphanumeric characters a bit exceeding proper limit. The possibility of setting video modulation factor within +/- 6% enables correction in such cases, optimizing the signal quality. In practice it is seen as no great change of brightness and contrast of the picture. Generally, when the original and converted by the modulator picture is of regular quality (no overmodulation), and sound is clear, no correction is needed.
The standard depth of video modulation is 75%, however sometimes it can be useful to change it a little, e.g. when a source generates alphanumeric characters a bit exceeding proper limit. The possibility of setting video modulation factor within ą6% enables correction in such cases, optimizing the signal quality. In practice it is seen as no great change of brightness and contrast of the picture, e.g. of that characters. Generally, when the original and converted by the modulator picture is of regular quality (no overmodulation), and sound is clear, no correction is needed.
Changing a little output frequency one may attempt to eliminate interferences coming from neighboring channels, when they are fixed in the system. Making offset of the output modulator's frequency there is a chance to solve that problem. The possible range is ą2,5 MHz at 250 kHz intervals. Generally, when the signals within installation are of good quality, that feature is not used.
| Name | | Modulator MT-21P |
| Code | R871721 | |
| Video baseband | Hz | 20...6M |
| Video input level (tolerance)/impedance | V+/-dB@ohm | 1 (+/-1) / 75 |
| Audio baseband | Hz | 20...15k |
| Audio input level/impedance/deviation | mV RMS/ kohm/kHz | 775/ 10/50 |
| Audio input signal level adjustment | dB | +1...-14 |
| Typical RF output signal level/impedance | dBuV/ohm | 85/75 |
| RF output level adjustment | dB | 0...-15 |
| Output channel range | 21-69 | |
| RF carrier deviation | kHz | +/-50 |
| Sound standards | B/G D/K mono | |
| RF carrier offset | MHz | max +/- 2.25. with 0.25 step |
| Video carrier to audio subcarrier ratio (+/-3dB change-over) | dB | 12/16 |
| Depth of modulation | % | 81 |
| S/N ratio | dB | >=58 |
| Intermodulation products of II and III order | dB | <-60 |
| Power | V/Hz/VA | 230/50/5 |
| Working temperature | oC | -10...+50 |
| Dimensions/weight | mm/kg | 78x118x47/0.37 |
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