EMCEE Broadcast Products TTU500FA ユーザーズマニュアル
MODEL 2000 TELEVISION MODULATOR
Page 5
Revised June 1999
improves. The input is configured as a bridging input and, if 600 ohm termination is required, an external
resistor may be connected between the + and
resistor may be connected between the + and
terminals on the plug.
An unbalanced line must be a shielded cable except for very short runs of a few inches. Hum and noise
pickup is likely due to the lack of common mode rejection as provided by a balanced line. The balanced line
should be used wherever possible.
pickup is likely due to the lack of common mode rejection as provided by a balanced line. The balanced line
should be used wherever possible.
For an unbalanced line, connect the center conductor of the shielded cable to the + terminal and the ground
to the ground terminal. The
to the ground terminal. The
terminal may be left unconnected or connected to the ground terminal by a
short piece of wire.
Video:
The video input is a standard 75 ohm “F” connector (BNC available as an option as are special terminating
impedances). This product is designed for sync negative video standard and a level of one volt p-p nominal.
A signal between one half and two volts will allow adjustment to proper modulation depth however.
impedances). This product is designed for sync negative video standard and a level of one volt p-p nominal.
A signal between one half and two volts will allow adjustment to proper modulation depth however.
A quality cable should be used for hookup. Hum in the video may be reduced by heavy bonding straps
between racks and proper grounding.
between racks and proper grounding.
All video lines should be as short as practical.
IF LOOP(S)
The IF loop(s) may be used for IF scrambling, switching or other purposes requiring levels of +40dBmV
nominal (video) at 75 Ohms.
nominal (video) at 75 Ohms.
All units with separate aural and visual outputs will have one loop for the video IF; this loop is prior to the
SAW filter so that any out-of-band spurious or harmonic products generated by external equipment
connected in the loop will be eliminated by the SAW filter.
SAW filter so that any out-of-band spurious or harmonic products generated by external equipment
connected in the loop will be eliminated by the SAW filter.
Units with composite outputs will have three loops, one pre-SAW filtered video IF loop, one audio IF loop
(level equal to video IF level minus the difference between the video and audio carriers), and a post SAW
filtered composite loop.
(level equal to video IF level minus the difference between the video and audio carriers), and a post SAW
filtered composite loop.
IF OUTPUT(S):
The main video IF output (or composite IF output) is a 75 Ohm “F” connector with a level of +45dBmV
maximum (up to +65dBmV available as an option). A level control is available on the front panel which will
allow reduction by a minimum of 20dB. This output is also available with an output frequency of the user’s
choice (internal upconverter and filters).
maximum (up to +65dBmV available as an option). A level control is available on the front panel which will
allow reduction by a minimum of 20dB. This output is also available with an output frequency of the user’s
choice (internal upconverter and filters).
The audio IF output (on products with separate outputs) will have a standard level of +40dBmV maximum
(higher available as an option) with a front panel level control allowing a minimum of 20dB reduction. The
audio IF is bandpass filtered.
(higher available as an option) with a front panel level control allowing a minimum of 20dB reduction. The
audio IF is bandpass filtered.