B&K Precision 1253 User Manual
Model 1253
HDTV Multi-Standard Pattern Generator
Operator's Manual
Version 3.00
Index
Introduction _________________________________________________________________ 2
Operation _________________________________________________________________ 3
Connecting the Unit ___________________________________________________________ 5
Power Supply ___________________________________________________________ 5
Low Battery Alarm ___________________________________________________________ 5
PATTERNS* _________________________________________________________________ 6
1: SMPTE Bars Pattern _______________________________________________ 6
2: PLUGE Pattern _____________________________________________________ 8
3: Needle Pattern _____________________________________________________ 9
4: Color Bars Pattern _____________________________________________________ 10
5: Cross Hatch Pattern _______________________________________________ 11
6: DVD Aspect Ratio Patterns ______________________________________________ 12
7: Raster Patterns _____________________________________________________ 14
8: Multiburst Pattern _____________________________________________________ 15
9: Focus Pattern _____________________________________________________ 16
10: Staircase Pattern _____________________________________________________ 17
11: ANSI Gray Pattern _______________________________________________ 18
12: Window Patterns _____________________________________________________ 19
13: Checker Pattern _____________________________________________________ 20
14: Overscan-Bounce Pattern _______________________________________________ 21
Specifications _________________________________________________________________ 22
Calibrating a HDTV Monitor _____________________________________________________ 24
Warranty Information ___________________________________________________________ 35
Service Information ____________________________________________________________ 36
* Patterns printed in the manual included with each 1253 is in black in white. To view the manual in color
and to take advantage of the examples given please visit www.bkprecision.com and download the 1253
manual.
For more application and support documentation please visit
www.bkprecison.com
and search the model 1253.
Introduction
Thank you for purchasing the BK-1253, the affordable HDTV-Component test-pattern-generator,
designed to be a useful tool for the new generation of DTV (Digital TV) products.
During the year 2001, over 1.1 million DTV units were shipped, exceeding expectations of the industry.
This trend should continue to grow, especially that the FCC has mandated the existence of DTV.
Presently 95.8% of U.S. can receive HDTV broadcasts. Now the major satellite companies such as
DirecTV and EchoStar, as well as the cable companies, are starting to transmit HDTV signals.
HDTV test equipment has been relatively expensive, compared to the old TV standards. Most major
brand HDTV test-pattern-generators sell for several thousands of dollars. This is prohibitively expensive
for many of the people getting into HDTV, such as the TV repair shop. So, at BK Precision we recognize
the need for a reliable, accurate, and high quality HDTV test-pattern-generator.
Due to the ever increasing popularity of DVD players, and the advent of newer display technologies being
introduced, such as Plasma, LCD, TFT, DLP, GLV and OLED, it was necessary to design patterns to test
these technologies.
Home theater is also growing in popularity, so we kept in mind the ease of operation, to allow any person
to operate the BK-1253.
There are several types of video inputs into HDTV monitors including YPbPr (called HD Component
Video), RGB, RGBHV, Firewire, and VGA). Fortunately the YPbPr interface is becoming standardized,
and has increased to presently cover about 90% of all monitors. Current models of HDTVs, Set-TopBoxes, and DVD players use this interface too. The BK-1253 therefore uses the YPbPr Video output too.
The BK-1253 has many uses, and is suited for a variety of different industries:
a) A TV repair engineer or technician, to test and calibrate a DTV monitor.
b) A video engineer, to test and maintain studio equipment, such as monitors, cabling, and recording
equipment.
c) A studio installer, to test cables and equipment.
d) A home-theater installer of user to get the best results out of the DTV equipment.
e) A store selling HDTV sets, to show side by side comparisons of quality.
f) A person wishing to test a new HDTV set for compatibility with the ATSC standards.
g) A teacher, to train their students in the latest HDTV technologies.
OPERATION:
The POWER Switch
This Power Switch, on the right side of the unit,
turns the power to the unit on and off.
Slide the switch the upward position to turn the
unit on. The red POWER LED will be on.
Slide the switch the downward position to turn
the unit off. The red POWER LED will be off.
The VIDEO FORMAT Button
This button is pressed prior to selecting a new
Video Format, followed by pressing a button to
one of the formats:
1) 1920 x 1080 30i (default on power-up)
2) 1920 x 1080 30p
3) 1920 x 1080 24p
4) 1280 x 720 60p
5) 1280 x 720 30p
6) 1280 x 720 24p
7) 704 x 480 60p
8) 704 x 480 30p
9) 704 x 480 30i
10) NTSC
11) PAL
12) SECAM
The same Pattern that was previously displayed (e.g. Color Bars) will be maintained when a new Video
Format is selected. After selecting a new Video Format, the unit reverts back to Pattern selection.
The most popular formats used today by the TV broadcasters and DTV equipment are 1, 4, 7 and 10.
These are conveniently the left column of buttons. The other formats may not be supported by many TVs.
Format 7 is now output by many newer DVD players, using Progressive-Scan.
Soon to follow in popularity may be format 3 and 6 because of the support by manufacturers, the movie
industry, and editing suites of the 24p format (the same frame rate as film cameras).
Note: When new formats become available, and standardized, they will be added to this list. The next
version may include the 704 x 480 24p Video Formats (standardized by the ATSC, but not yet by
SMPTE). Contact the factory for upgrade information.
The PATTERN Buttons
These 14 buttons may be pressed at any time, to select the Pattern displayed as an icon on the button.
Some Pattern buttons may be pressed multiple times, to display variations of that particular pattern.
1) SMPTE Bars 75% (default on power-up)
2) PLUGE
3) Needle
4) Color Bars 75%
5) Cross Hatch [16:9]
6) DVD Aspect Ratio [1.33, 1.78, 1.85, 2.35]
7) Raster [75%: White, Yellow, Cyan, Green, Magenta, Red, Blue, Black]
8) Multiburst
9) Focus
10) Staircase
11) ANSI Gray
12) Window [2.5 IRE steps from Black to White]
13) Checker
14) Overscan - Bounce
The same Video Format previously displayed (eg 1280x720 60p) will be maintained, when a new pattern
is selected.
Pressing the DVD Aspect Ratio button multiple times, sequences through the most popular DVD aspect
ratios (1.33:1, 1.78:1, 1.85:1, 2.35:1). These aspect ratios cover 78% of all movies recorded to DVD
media. Read Appendix E: DVD Aspect Ratios for particular movies. DVD players output either 720x480
60p (progressive DVD), NTSC or PAL. Some broadcasters transmit HDTV at these aspect ratios but in
the higher resolutions
Pressing The Raster button multiple times, sequences the full-screen output through 8 colors, at 75%
amplitude: White, Yellow, Cyan, Green, Magenta, Red, Blue, and Black.
Pressing the Window button multiple times, or holding the Window button, sequences the window
luminance through all the grays (from black to white), in steps of 2.5 IRE units.
Connecting the unit
There are 3 BNC connectors on the top of the unit, labeled Y, Pb and Pr.
These are HDTV-Component video connections to be connected to the Y, Pb and Pr connectors of a
HDTV monitor or TV with component video input. There is also a DIN connector, labeled S-VID. This is
a S-Video (S-VHS) video connector to be connected to a TV with a S-VID input.
S-Vid Y Pb Pr
TOP
Pr Pb Y S-VID
Facing Connectors
Top (Button) Side
The Y is the luminance signal, and Pb and Pr are the chrominance (color) signals. These BNC connectors
should be connected to BNC cables with a characteristic impedance of 75 (or 50) ohms. Some TVs use
RCA connectors, so a BNC-to-RCA adaptor could be used at the end of each cable.
According to the standards, the Y signal will drive a 1V peak-to-peak signal into a 75-ohm load, and the
Pb and Pr signals will drive 0.7V peak-to-peak signals into 75-ohm loads. The unit is correctly backterminated with 75 ohm impedance for each connector.
The Y signal can be used alone in some cases, to test using luminance only of an NTSC, PAL or SECAM
TV using its Composite input. The signal will be seen as a monochrome image, which is fine for most
patterns which are monochrome.
The S-VID may be used to test most non-HDTV monitors, which may have a S-Video input. This
connection provides no chrominance, so 3 color patterns (SMPTE Bars, Color Bars, and Raster) will
display only luminance and no color. The other 11 patterns will display normally.
The outputs of the unit have independent buffers so incorrectly loading an output will not affect the other
outputs. The outputs are also designed to drive short-circuit loads under abnormal conditions.
Power Supply
The unit is powered from an internal 9V battery.
A 9V Alkaline battery (e.g. Eveready Energizer 522) is recommended.
The unit is low power, and it should work under most normal operating conditions. There is a thermal
shutdown, as well are reverse protection function in the internal power supply circuitry for safety.
Low Battery Alarm
When the battery is low, a long beeping sound will be heard when the unit is switched on. You will need
to replace the battery soon after this. There will be a few hours of battery life left when you first hear this,
so this is a warning alarm, so be sure to replace the battery. If the unit is used for a few hours after this,
the battery will become depleted, and the unit will cease to function.
Patterns
1: SMPTE Bars
(Society of Motion Pictures and Television Engineers)
Description: 7 equal width vertical bars in 3 groups. The top 2/3 of the pattern contains White (R+G+B),
Yellow (R+G), Cyan (G+B), Green (G), Magenta (R+B), Red (R), and Blue (B) bars, from left to right, at
75% (100% saturation).
The middle 2/15 of the pattern contains the blue's complement color for each of the bars above which
contain blue: Blue (B), Black, Magenta (R+B), Black, Cyan (G+B), Black, and White (R+G+B)
The bottom 1/5 of the pattern contains the following bars:
-I, White 100%, Q, Black, Blacker-than-black at -5 IRE (2.5 IRE for NTSC), Black = 0 IRE (7.5 IRE for
NTSC), and Lighter than-black at 5 IRE (12.5 IRE for NTSC).
Pattern Usage: Use to adjust color and hue through a blue filter. While viewing the pattern through a
blue filter (Wratten 50), adjust the color control for equal brightness white/blue bars. Adjust the hue
control for equal brightness cyan/magenta bars. Also use this pattern to adjust a display’s black level at a
medium APL. With the brightness (black level) control first adjusted to a slightly higher than normal
setting, reduce the brightness control setting until the slightly blacker than black bar (under the large cyan
bar) and the black bar (under the large red bar) are both just black. The slightly whiter than black bar
(under the large blue bar) should still be slightly visible.
Monitor setup with these color bars is fairly simple. With SMPTE color bars on the monitor, again adjust
brightness so the -5 IRE (2.5 IRE for NTSC) pluge signal just disappears. If you can't see it, adjust
contrast and brightness to raise the black level towards gray. Then reset the brightness to just make the
lowest step disappear. Next, turn on the blue gun only and adjust the monitor Hue (phase) so first there
are four blue bars separated by three black bars. Third, adjust the Color (chroma) so the outer two blue
bars match between upper and middle bands. Finally, fine tune phase so the middle two bars match
between upper and middle bands. If required, fine tune Hue and Color so there is no visible difference
between any of the blue bars in the first and second bands.
There are various other applications for SMPTE Bars. It has value in VTR testing and in quick checks of
the system phasing thru monitors and Vectorscopes.
Vectorscope Display of SMPTE Bars
SMPTE Bars are also often used for Tape Headers, or sometimes between edit cuts. Also often used for
testing transmission equipment.
Examples of Uncalibrated Displays: The following images indicate a TV with incorrect hue settings.
Adjust the Hue (or Tint) setting so the first bar appears white (or gray).
Too Red Too Green Too Blue
2: PLUGE (Picture Line Up Generator Equipment)
Description: The Pluge pattern (Picture Line-Up Generator Equipment – BBC development) is arranged
in four concentric rectangular zones. The innermost rectangle is fixed at black (7.5 IRE for NTSC, 0 IRE
for other formats) and has a five-step gray scale positioned on it. The second rectangular zone from the
center alternates between two light levels, black and slightly blacker than black (7.5/0 IRE for NTSC, 0/-5
IRE for other formats). The third rectangular zone from the center is fixed at a light level slightly whiter
than black (10 IRE). The fourth, outer rectangular zone is fixed at black. The average picture level (APL)
of this pattern is very low.
Pattern Usage: Use this pattern to check the DC restoration (black clamping) performance of a display
device and to set the picture black level with a low APL pattern. A display device with less than perfect
DC restoration will exhibit alternating changes of brightness in the outer two rectangular zones, due to the
display’s inability to perfectly clamp black to a fixed level. This can be seen especially well with the
brightness (black level) control adjusted to a slightly higher than normal setting. If the brightness level of
the outer two rectangular zones remain constant as the second zone from the center alternates between
black and blacker than black, the display has good DC restoration.
If a display has good DC restoration, its brightness (black level) control can be adjusted on either a low
APL or high APL pattern, with no change in black level as you switch from one pattern to another. In that
case, this pattern makes it very easy to accurately adjust the brightness control. With the brightness (black
level) control first adjusted to a slightly higher than normal setting, reduce the brightness control setting
until the brightness alternations in the second rectangular zone from the center are just no longer visible.
The third rectangular zone from the center should still be visible as slightly whiter than black.
If a display device has less than perfect DC restoration, you will need to decide, based on the primary use
of the display, whether the black level should be adjusted on a pattern with low APL or high APL. If the
display will usually be viewed in a darkened room, adjust the brightness control with a low APL pattern,
such as this Pluge pattern. If the display will usually be viewed in a bright room, adjust the brightness
control with the pluge levels in a medium or high APL pattern, such as the SMPTE Bar pattern or one of
the Window patterns set to a high IRE level.
Examples of Uncalibrated Displays:
high, because flashing rectangle is visible. Adjust the brightness down until the flashing just disappears.
Flashing Inner Rectangle
should not be visible
The following image indicates a TV with the Brightness set too
3: Needle
Description: This pattern is black on the top half and white on bottom half, with lines (needle pulses)
drawn from top to bottom on each side of the pattern, through the black/white transition. Electrically, the
needle pulse lines are the same width on the top and the bottom of the pattern.
Pattern Usage: This pattern makes it easy to detect whether scan velocity modulation (SVM) is enabled
on a display device. If SVM is enabled, the black lines on the bottom of the pattern will be thicker than
the white lines on the top of the pattern. It is also a good pattern for properly adjusting the
contrast/picture/white level control for maximum white luminance level. If the contrast/picture control is
adjusted for a higher white level than the display device is capable of producing properly, one of two
distortion effects will be observed; blooming or raster distortion. Blooming is especially prevalent in CRT
displays and results in light from very bright pixels (phosphors) spilling over to adjacent pixels. This
causes bright picture areas to become defocused and slightly larger than they should be.
Raster distortion at high luminance levels is caused by high voltage power supply regulation problems. If
the contrast/picture control is adjusted for a higher white level than the display power supply is capable of
fully supporting on a short-term basis, the black lines on the bottom of the pattern will hook or bend
outward.
Ideally, for an accurate picture, the contrast/picture control should be adjusted just below the point at
which either blooming or raster distortion is evident. This may result in an unacceptably low white level
for the picture, however, and a compromise white level adjustment may have to be made between an
accurate picture and a bright picture.
Examples of Uncalibrated Displays:
by the Needle pattern. The first image has outwardly bent lines. The Contrast/picture levels may be set too
high, or the TV may have poor power supply regulation.
The second image shows blooming, where the white lines appear thicker than the black lines. Correct this
by adjusting the contrast/white level.
Bent Lines
The following images indicate a TV with incorrect settings, shown
Blooming White lines
4: Color Bars
Color Bars 75%
Same as the top of the SMPTE Bars Pattern
Description: Seven equal-width vertical bars with 75% (gray) at left, followed by three primary and
three secondary colors. Color bars are at 100% saturation with 75% amplitude.
Pattern Usage: Use as an overall check of a display device’s capability of producing fully saturated
primary and secondary colors. Especially helpful in detecting full (or partial) loss of colors in older
displays. Also good as a reference input signal when troubleshooting and signal tracing color amplifier or
color demodulator problems within a display device.
Examples of Uncalibrated Displays: The following images indicate a TV with incorrect hue settings.
Adjust the Hue (or Tint) setting so the first bar appears white (or gray).
Too Red Too Green Too Blue
5: Cross Hatch
Description: A grid of 16 x 9 boxes, separated by white lines.
Pattern Usage: Used to check and adjust convergence of red, green and blue pictures. The horizontal and
vertical lines are usually best observed to detect color fringing resulting from misconvergence, and the
dots are usually best observed to make fine adjustments.
Even if a display device provides an internally generated crosshatch pattern for checking convergence, it
is often best to double-check the convergence with an externally generated pattern. Occasionally, a
display’s convergence on an internally generated pattern doesn’t match its convergence on external input
video signals.
Also used to check and adjust for the proper geometry of a display, including picture centering, size,
trapezoid (keystone) correction, pincushion (bow) correction, and linearity. Horizontal and vertical
centering controls should be adjusted to center the pattern on the display screen.
Trapezoid correction control(s) should be adjusted to make the pattern’s edges parallel to the edges of the
display screen. Pincushion correction controls should be adjusted to straighten the lines to be straight, and
parallel to the edge of the screen. Use the edge of the display screen or a flexible straightedge, such as a
yardstick, to judge the straightness of the lines. The horizontal linearity control should be adjusted to
make the pattern boxes all the same width. The vertical linearity control should be adjusted to make the
pattern boxes all the same height.
Examples of Uncalibrated Displays:
The White lines become separated Red, Green and Blue lines. They are either straight or curved. Adjust
the RGB convergence controls to align the colors to overlap, so the Cross Hatch pattern appears as a grid
of white squares.
Linear Misconvergence Non-Linear Misconvergence
The following images indicate a TV with misconvergence.
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