The DRACOM 300VMF+ fixed channel video modulator is a quality vestigial sideband heterodyne audio/video modulator that provides a modulated visual and aural RF carrier output on any single channel up to 552 MHz. The 300VMF+ is designed to accept video and audio baseband signals from a satellite receiver, TV camera, or any compatible source.
Heterodyne conversion system, in conjunction with the use of a SAW filter, insures optimum vestigial selectivity for adjacent channel headends.
Accepts standard (sync. Negative) polarity video at 0.7 to 1.5 Vp-p level.
All level controls are conveniently located on the front panel.
High output power to +55 dBmV.
A convenient monitor port is provided.
All aeronautical channels are offset positive with a tolerance of ? 5 kHz as required by FCC rules.
Rear Panel AC line convenience outlet.
Dracom 300VMF+ Technical Specifications
54 through 552 MHz.
CATV Channels 2 through 78 and 95 through 99
FCC Frequency Offsets:
All aeronautical channels offset positive with a tolerance of ?5 kHz.
+55 dBmV minimum, (typically adjustable from +43 to +55 dBmV).
75 Ohms; return loss of 14 dB nominal.
Audio Carrier -20 to -12 dB referenced to video carrier, adjustable.
Frequency Stability, Visual:
Within ? 10 kHz of assigned channel frequency. Within ?5 kHz of assigned channel frequency on FCC offset channels.
Aural Intercarrier Frequency:
4.5 MHz, ? 5 kHz.
-60 dBc minimum, measured at -15 dB A/V ratio and with modulator output level of + 55 dBmV.
Better than 60 dB.
-95 dBc @ ? 30 MHz or greater spacings. (Specified levels are referenced to the video carrier and measured in a 4 MHz bandwidth.)
Input level for 87.5% modulation:
1 Vp-p ? 3 dB, manual gain adjust with front panel control.
75 Ohms, return loss of 18 dB minimum.
Flat ? 2 dB from 30 Hz to 4.2 MHz.
60 dB minimum, luminance weighted.
Within 50 nanoseconds of 0 nanoseconds L/C delay (complies with FCC rule 76.605).
Less than ? 5% (10 to 90% APL).
Less than ? 5 degrees (10 to 90% APL).
Input Level for 25 kHz Peak Deviation:
175 mV rms minimum. Manual gain adjustment with front panel control.
10K Ohms, unbalanced.
75 m Sec.
40 Hz to 15 kHz, ?1.5 dB, referenced to 75 m Sec. pre-emphasis curve.
4.5 MHz Intercarrier Stability:
? 5 kHz, 0 degrees Celsius to + 50 degrees Celsius.
Total Harmonic Distortion:
Hum and Noise:
-60 dB minimum, referenced to 25 kHz peak deviation.
AC Power Input:
115 VAC ? 10%, 60 Hz, 10 Watts.
Operating Temperature Range:
0? to 50? Celsius, ambient.
1.75 inches Height x 19 inches Width x 4.0 inches Depth.
Video input, Audio Input, monitor and RF output are all type F.