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1.0
General
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1.1
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Q.
Is the HDG-2000 compatible with professional
HDTV standards?
A.
Yes.
The HDG-2000 generates RGB and
YPbPr analog component video signals
according to the signal levels, sync types, pixel
formats, and clock timing specified by SMPTE 274M
(1080i) and SMPTE 296M (720p). These are the
standards used for broadcast HDTV in the U.S.
Select either YPbPr or RGB, and
Tri-Level Sync. Select either 1080i
or 720p for SMPTE 274M or SMPTE 296M
respectively.
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1.2
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- Q.
Is the HDG-2000 compatible with HDTV
signal formats used by consumer
HDTVs?
A.
Yes.
Consumer Set-Top Boxes, HDTVs and HD-compatible
front and rear projectors use a wide variety of
signal and sync formats. Some produce or accept
RGB signals and some YPbPr. Some
produce or accept Bi-Level sync, but not
Tri-Level sync. Some produce no sync on the
video signals at all, instead using separate
positive or negative H
(horizontal) and V (vertical) sync, or
Composite sync. The HDG-2000 provides
the ability to individually select combinations of
these video and sync formats to work with any HDTV
display. It produces YPbPr and RGB
signal formats with embedded sync on the video
signals (Bi-Level Sync, Tri-Level
Sync, or none), separate HV sync signals
(Positive, Negative, or none), or a
separate Composite sync signal
(Positive, Negative, or none). In
addition other non-standard consumer formats are
included that combine signal Setup (pedestal) or
signal Offset with any of the preceding varations.
See 2.0 Output
Modes
and 3.0 Sync
Signals
for further information.
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1.3
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- Q.
The HDG-2000 produces analog HDTV
component video signals. Are the patterns
generated by analog means?
A.
No. The
HDG-2000 pattern and sync signal timing is
generated by proprietary digital integrated
circuits driven by a highly accurate, low-jitter
74.17582 MHz fixed-frequency crystal oscillator.
This frequency is 74.25/1.001 MHz as specified by
SMPTE 274M (1080i) and SMPTE 296M (720p) for HDTV
at the standard 59.94 Hz U.S. field rate (1080i)
and frame rate (720p).
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1.4
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- Q.
How are the analog signal levels of the patterns
generated?
A.
The signal levels are stored as separate 30-bit
RGB and YPbPr values (10-bits for
each component) in proprietary programmable digital
ICs, and converted to analog output signals by
three precision 10-bit Digital-to-Analog
converters.
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1.5
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- Q.
How long does it take to switch
patterns?
A.
The test patterns are generated in real-time by
digital ICs so switching between patterns is
instantaneous.
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1.6
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- Q.
Are 60 Hz, rather than 59.94 Hz, field and frame
rates available for other countries?
A.
Yes, by special order.
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1.7
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- Q.
What type of high-definition video output
connectors does the HDG-2000
have?
A.
The HDG-2000 has 75-ohm BNC video/sync
output connectors, and a 15-pin HD (VGA type)
monitor output . Both outputs can be used at the
same time and both carry YPbPr or RGB
component video signals, and HV (or
C) sync signals.
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2.0
Output Modes
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2.1
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- Q.
What is the YPbPr output
mode?
A.
This is the
three-cable HDTV analog component video signal
interface used by most Direct-View and
Rear-Projection HDTVs. Connections at the display
are usually made with BNC or RCA phono connectors
on each cable. Y is the luma signal. Pb
and Pr are color-difference signals.
Sync signals are embedded in either the Y
signal (Bi-Level sync) or all three
YPbPr signals (Tri-Level sync per
SMPTE 274M and SMPTE 296M). Displays that conform
only to EIA 770.3 ignore the Tri-Level sync
on the Pb and Pr signals.
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2.2
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- Q.
What is the RGB output mode?
A.
Most Front-Projectors, some Rear-Projection HDTVs,
and all computer monitors use RGB component
video signals. Computer monitors and most
projectors accept separate H (Horizontal)
and V (Vertical) sync signals in addition to
the R (red), G (green) and B
(blue) signals. The RGB/HV signal format
requires 5 separate coax cables, although they are
often enclosed in a single jacket. The cables can
be terminated with separate connectors, usually
BNCs, or with a computer-style VGA 15-pin
D-connector. Some projectors require the H
and V sync signals to be combined into a
single Composite (C) sync signal so
that only 4 cables are needed. Another RGB
format option is to embed Bi-Level sync in
the G signal, or Tri-Level sync in
all three RGB signals. This can reduce the
number of cables required to only three (3).
However, the same embedded sync signals are also
often included with the RGB/HV or
RGB/C formats. The HDG-2000 can
provide all of these RGB signal and sync
combinations, including the choice of either
positive or negative HV and
C sync polarity.
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2.3
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- Q.
What is the YPbPrs output mode?
A.
This is the
YPbPr mode with a 7.5 IRE black-level
setup (pedestal) on the Y signal. This
mode is intended for compatibility with some
consumer upconverters that convert
standard-definition YPbPr component video
with 7.5 IRE setup, to high-definition
YPbPr component video without removing
the setup. However, many DVD players also have
an "Enhanced-Black" or "Dark" option to remove
the 7.5 IRE setup from their YPbPr
output. In that instance the HDG-2000
YPbPr output mode with Bi-Level
sync should be used for compatibility with
Upconverters.
Professional
Upconverters compatible with the SMPTE 274M and
SMPTE 296M HDTV standards will remove any setup and
convert Bi-Level sync to Tri-Level
sync . Use the HDG-2000 YPbPr output
mode with Tri-Level sync selected to
generate SMPTE 274M (1080i) and SMPTE 296M (720p)
standard YPbPr signals.
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2.4
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- Q.
What is the RGBs output mode?
A.
This is the RGB mode with a 7.5 IRE
black-level setup (pedestal) added to the
R, G and B signals. This
mode is intended for compatibility with some
consumer upconverters that convert
standard-definition YPbPr component video
with 7.5 IRE setup to high-definition RGB
component video without removing the setup.
However, many DVD players also have an
"Enhanced-Black" or "Dark" option to remove the
7.5 IRE setup from their YPbPr output. In
that instance the HDG-2000 standard
RGB output mode should be used for
compatibility with Upconverters.
Professional
Upconverters compatible with the SMPTE 274M and
SMPTE 296M HDTV standards will remove any setup and
convert Bi-Level sync to Tri-Level
sync. Use the HDG-2000 RGB output mode, with
Tri-Level sync selected to generate SMPTE
274M (1080i) and SMPTE 296M (720p) standard
RGB signals.
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2.5
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- Q.
If the YPbPrs and RGBs modes have
7.5 IRE setup, what is their peak-white output
level?
A.
The
YPbPrs and RGBs modes produce 700 mV
peak-white signal levels.
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2.6
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- Q.
The RCA DTC-100 HDTV Satellite Receiver is a
very popular HDTV set-top box the receives
High-Definition programming from DirecTV and
terrestorial broadcast stations. Its RGB
outputs include setup. Should the RGBs
mode be used to calibrate displays for
compatibility with the RCA DTC-100?
A.
A
special HDG-2000 mode is provided for the
DTC-100. The DTC-100 includes a 7.5 IRE offset in
the RGB outputs with a peak-white level 714
mV above the 7.5 IRE level. This produces an
extraordinarily high peak-white level that may
generate white-level clipping in fixed-pixel
projectors unless the Contrast control is
calibrated for these high levels. To select the
HDG-2000's special DTC-100 mode, press the
Output and Sync keys simultaneously and
release. The HDG-2000 signal amplitude will
be compatible with the DTC-100. The embedded
Sync mode will be set to off and the
HV/C mode to positive HV sync,
the sync types used by the DTC-100.
For
compatibility with other non-standard products in
the future you can change Sync and HV/C
modes, or select YPbPrs, and the signal
amplitude will remain at the higher level with
setup. The YPbPr and RGB output modes
(without setup) will retain normal calibration
levels. To restore the YPbPrs and
RGBs signals to their normal calibration
levels remove (for at least 5 seconds) and then
restore power to the HDG-2000.
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3.0
Bi-Level/Tri-Level Sync
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3.1
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- Q.
What is Bi-Level Sync?
A.
Bi-Level
sync is a negative going pulse added to the
beginning of each scan line on the Y signal
in YPbPr (or YPbPrs) output mode, or
the G signal in RGB (or RGBs)
output mode. The sync pulse amplitude is nominally
-0.3 volts below the blanking level. (The sync
pulse amplitude is nominally -0.278 volts in the
YPbPrs and RGBs output modes.) The
Bi-Level sync pulse width is 40 clock cycles
(539 nS) for 720p and 44 clock cycles (593
nS) for 1080i. Bi-Level sync is used
by standard-definition TV systems such as NTSC and
PAL, and for the YPbPr and RGB
component video formats prior to the introduction
of HDTV.
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3.2
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- Q.
What is Tri-Level Sync?
A.
Tri-Level sync consists of a negative going
pulse, followed by a positive going pulse, added to
the begining of each scan line on each of the
Y, Pb, and Pr signals in
YPbPr (or YPbPrs) output mode, or on
each of the R, G, and B
signals in RGB (or RGBs) output mode.
The negative sync pulse amplitude is nominally -0.3
volts below the blanking level and the positive
sync pulse amplitude is nominally +0.3 volts above
the blanking level. (Sync pulse amplitudes are
nominally -0.278 volts and +0.278 volts in
YPbPrs and RGBs output modes.) The
negative and positive portions of
theTri-Level sync pulses each have a width
of 40 clock cycles (539 nS) for 720p and 44
clock cycles (593 nS) for 1080i.
Tri-Level sync is specified by the SMPTE
274M and SMPTE 296M HDTV standards.
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3.3
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- Q.
If SMPTE 274M (1080i) & SMPTE 296M (720p)
specify Tri-Level sync what is the
purpose of Bi-Level sync
mode?
A.
Many
existing Front Projectors are capable of displaying
HDTV but are not fully compatibile with
Tri-Level sync. So many HDTV Set-top Box and
Satellite Receiver manufacturers have not
implemented Tri-Level sync; preferring
instead to use Bi-Level sync to maximize
compatibiity with existing display products. Those
that have implemented Tri-Level sync often
provide a choice of output signal formats. The
HDG-2000 provides both Tri-Level and
Bi-Level sync for YPbPr and
RGB signals to match the source
components.
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3.4
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- Q.
Why can both Bi-Level and
Tri-Level sync be turned off in the
RGB output modes but not in
YPbPr?
A.
Both
Bi-Level and Tri-Level sync can be
turned off in the RGB output modes because
some manufacturers do not put any embedded sync on
the RGB signals (the RCA-DTC100 Satellite
Receiver is one example). They rely instead on the
separate H (Horizontal) and V
(Vertical) sync signals to synchronize the display.
In this case if the display is calibrated with
Bi-Level or Tri-Level sync turned on
errors in black-level and color saturation may
result. Since YPbPr signals never use
HV sync, either Bi-Level or
Tri-Level sync must be used and therefore
can't be turned off.
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3.5
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- Q.
How do I know when to use Tri-Level
sync?
A.
In
most cases the display device will include a menu
item that specifically indicates Tri-Level
sync, or the manual will specify Tri-Level
sync inputs for the device. You should only use
Tri-Level sync from the HDG-2000 when
the display device specifically has this mode.
Using Tri-Level sync with displays set to
Bi-Level sync may introduce black-level and
color saturation errors. When in doubt use
Bi-Level sync.
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4.0
HV & C Sync
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4.1
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- Q.
How do I know if a source is using HV
sync without either Tri-Level or
Bi-Level sync?
A.
Unplug
the separate H & V sync signals
going to the display. If the display stops
synchronizing the picture then the source is not
outputting Bi-Level or Tri-Level sync
on the RGB signal lines. In this case it is
best to turn off the RGB sync from the
HDG-2000 and use only HV
sync.
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4.2
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- Q.
Why can I turn on HV sync in YPbPr
output mode if the display doesn't use these
separate sync signals?
A.
The
HDG-2000 provides HV sync signals in
the YPbPr mode for synchronizing (or
triggering) a monitor device like an oscilloscope.
These signals are provided as a user convenience
because the video display does not use them.
However, if a VGA connector is used for a projector
input, the HV sync signals could confuse the
projector into thinking it was receiving RGB
signals, so they can be turned off at the
generator.
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4.3
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- Q.
What if the display has RGB inputs with
Composite sync instead of HV
sync?
A.
The
HDG-2000 is very versatile and will provide
Composite sync. To turn on Composite
sync press the HV/C button and the
Sync button simultaneously and then release.
Press the HV/C button again as required to
select Pos, Neg, or no
Composite sync. The HDG-2000 will
remain in the Composite sync mode until the
power is removed for at least 5 seconds. When it is
powered on again it will be restored to the
HV sync mode. (Note: In Composite
sync mode the vertical sync will still be available
on the V sync output to be used for
triggering a monitoring device such as an
oscilloscope.)
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4.4
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- Q.
Why can the polarity of the HV (&
C) sync signals be changed? Which should
be used?
A.
There
are no set standards for using these signals and
some manufacturers use negative sync and
others use positive sync. As always you
should try to use the same signals as the source
devices. The display will often have an information
screen to indicate whether it is receiving
negative or positive HV sync,
or a setup screen to choose which to use. Many
displays only work with one polarity and not the
other. If there is no indication or selection
method, and the display works with both, then use
negative sync because it is more
common.
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4.5
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- Q.
Why can the HV/C sync signals be turned
off entirely?
A.
The
SMPTE HDTV standards (SMPTE 274M & 296M)
specify Tri-Level sync for RGB
signals, and YPbPr signals, HV
sync is not used. There are also some displays
that work with Bi-Level sync
(sync-on-green) that do not accept HV
sync.
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4.6
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- Q.
What is the amplitude of the HV &
C Sync signals?
A.
The
H, V, and C Sync signals are
positive or negative pulses with a nomimal low
level of 0 volts and a nominal high level of 4
volts when connected to standard 75 ohm loads. Each
sync signal is reverse terminated by 75 ohms for
optimal pulse shape over long sync cables. When
both the BNC outputs and the 15-pin D-connector
(VGA) output are used at the same time the sync
pulse amplitude is reduced to a nominal 2.67
volts.
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4.7
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- Q.
What is the width of the HV &
C Sync signals?
A.
The
width of the H sync signal is equivalent to
the combined width of the positive and negative
portions of Tri-Level sync, 1078 nS for
720p and 1186 nS for 1080i. The
V sync pulse is the combined width of frame
lines 1-5 in the 720p format and field lines
1-5 or field lines 262.5-267.5 in the 1080i
format.
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5.0
720p and 1080i Format Modes
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5.1
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- Q.
What is the pixel format of
720p?
A.
A
720p format (SMPTE 296M) frame includes 750
total lines. Each line is equivalent in length to
1650 total pixels. The active picture area of each
frame is 720 lines with 1280 active pixels,
equivalent to a pixel frame format of 1280 x
720.
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5.2
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- Q.
What is the sampling frequency, frame rate, and
horizontal scan rate of 720p?
A.
In
the U.S. the frame rate is exactly 60/1.001 Hz, or
approximately 59.94 Hz. The sampling rate is
defined by SMPTE 296M to be 74.25/1.001 MHz, or
approximately 74.17582 MHz. The horizontal scan
rate is therefore approximately 44.955 kHz. The
HDG-2000 uses a precision, low-jitter,
74.17582 MHz cut-crystal oscillator and conforms to
these standards. A 60 Hz frame rate version is
available by special order.
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5.3
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- Q.
What is the pixel format of
1080i?
A.
A
1080i format (SMPTE 274M) frame consists of
two interlaced fields. Each field includes 562.5
total lines. Each line is equivalent in length to
2200 total pixels. The active picture area of each
frame is 1080 lines (540 lines per field) with 1920
active pixels, equivalent to a pixel frame format
of 1920 x 1080.
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5.4
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- Q.
What is the sampling frequency, field rate, and
horizontal scan rate of
1080i?
A.
In
the U.S. the field rate is exactly 60/1.001 Hz, or
approximately 59.94 Hz. Therefore the frame rate is
30/1.001 Hz, or approximately 29.97 Hz. The
sampling rate is defined by SMPTE 274M to be
74.25/1.001 MHz, or approximately 74.17582 MHz. The
horizontal scan rate is therefore approximately
33.716 kHz. The HDG-2000 uses a precision,
low-jitter, 74.17582 MHz cut-crystal oscillator and
conforms to these standards. A 60 Hz field rate
version is available by special order.
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