Drake 300VMF+ Fixed Modulator - Manual (Page 3)

Table of Contents/Description/Specifi cations 3
TABLE OF CONTENTS
2 Caution Statements 5 Rear Panel Connections and Internal Jumper
2 Important Safety Instructions 6 Installation
3 Table of Contents / General Description 7 Frequency Allocation Charts
3 Specifi cations 8 Service / If You Need To Call For Help
4 Front Panel Controls, Indicators, and 9 Warranty
Connections
DESCRIPTION
The DRACOM 300VMF+ Video Modulator is a vestigial sideband heterodyne audio/video modulator that provides a
modulated visual and aural RF carrier output on any single EIA standard channel from channel 2 through channel 78 plus
channels 95 to 99. This range covers 54 through 552 MHz. Consult factory for custom channels. All aeronautical chan-
nels are offset positive with a tolerance of ±5 kHz as required by FCC rules. The 300VMF+ is designed to accept video
and audio baseband signals from a satellite receiver, TV camera, video tape recorder, TV demodulator or similar equip-
ment. The heterodyne conversion system, in conjunction with the use of a SAW fi lter, insures optimum vestigial selectivity
for adjacent channel headends. The modulator accepts standard (sync negative) polarity video at a 0.7 -1.5 Vpp level. All
level controls are located on the front panel for ease of operation.
SPECIFICATIONS
54 - 552 MHz.
Factory-ordered for a single channel:
EIA CATV channels 2 to 78 and 95 to 99.
All aeronautical channels offset positive
with a tolerance of ±5 kHz.
+55 dBmV, (typically adjustable from +43
to +55 dBmV).
75 OHMS, return loss of 14 dB, nominal.
-30 dB, ±3 dB (referenced to
RF OUTPUT level).
Audio Carrier -20 to -12 dB referenced to
video carrier, adjustable.
Within ±10 kHz of assigned channel
frequency; ±5 kHz on FCC
offset channels.
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. (Specifi ed levels are
referenced to the video carrier and
measured in a 4 MHz bandwidth).
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, luminance weighted.
Within 50 nSec of 0 nSec L/C delay
(complies with FCC rules, 76.605).
Less than ±5% (10 to 90% APL).
Less than ±5 degrees (10 to 90% APL).
175 mV rms minimum. Manual gain
adjustment with front panel control.
10K Ohms, unbalanced.
75 mSec.(fl at by moving internal jumper)
40 Hz to 15 kHz, ±1.5 dB, referenced to
75 mSec pre-emphasis curve.
Within ±5 kHz, 00 C to +500 C.
1.5% maximum.
-60 dB minimum, referenced
to 25 kHz peak deviation.
115 VAC ±10%, 60Hz, 10 Watts.
Nominal 120 VAC, 600 Watts, maximum.
Nominal 120 VAC 60 Hz,
610 Watts, maximum.
0 C to +50 C, ambient.
19” W x 1.75” H x 4.0” D.
3.6 lbs.
Video input, Audio input, RF output, and
Monitor output are all type F.
RF
Frequency Range:
Channels Available:
FCC Frequency
Offsets:
Output Level:
Output Impedence:
Output Test:
A/V Ratio:
Frequency Stability,
Visual:
Aural Intercarrier
Frequency:
Spurious Outputs:
In-Channel C/N:
Broadband Noise:
VIDEO
Input level for 87.5%
Modulation:
Input Impedance:
Frequency Response:
Video S/N:
L/C Delay:
Differential Gain:
Differential Phase:
AUDIO
Input Level for
25 kHz Peak Deviation:
Input Impedance:
Pre-emphasis:
Frequency Response:
4.5 MHz Intercarrier Stability:
Total Harmonic Distortion:
Hum and Noise:
GENERAL
Modulator Power
Requirement:
Auxiliary AC Outlet:
Total AC Power Input:
Operating Temperature
Range:
Size:
Weight:
Connectors: