B&K Precision 1249B - Manual - Manual (Page 4)

4
INTRODUCTION
T he B+K PRECISION Model 1249B NTSC Generator is a
versatile, low cost, precision television/video signal
generator. It generates a variety of test signals and patterns for
comprehensive testing, servicing, and adjustment of video and
television equipment. Its applications include television
receivers, video tape recorders, closed circuit television
systems and components, and master antenna systems and
components, as well as most standard computer and video
monitors.
The instrument can generate many different patterns, each of
which is available as a composite video signal or a modulated
rf output on channel 3, channel d, or the standard television i-f
frequency of 45.75MHz. This provides the proper signal for
injection at any point in the equipment.
The video patterns include standard NTSC color bats with
standard 75% white or with 100% white, staircase, black raster,
and an assortment of convergence patterns. An engineer or
technician with a good knowledge of video circuits can use the
variety of patterns to analyze and isolate almost any video
problem.
The NTSC Color Bars signal generated by the instrument is
the same type of color bar signal that is used by the television
networks, allowing
it to be used to set-up and adjustment TV sets and other
equipment for the best performance. This is not possible
with lower cost gated rainbow color generators, which
produce a signal unlike that used during normal operation.
Separate RGB and sync outputs are available for use with
most computer and video monitors using standard 525 line.
15.750KHz scan. The inputs to these RGB monitors are
separate digital signals for red, green, and blue, and separate
digital composite sync or separate digital vertical and
horizontal sync. The signal level at the RGB outputs is switch
selectable between TTL and low (0.8V). The D-type
subminiature connector is directly comparable with IBM
Model 5153 PC monitors (TTL signal level should be
selected for use with the IBM PC monitor).
Other features include a crystal generated 30Hz TTL output
and a switchable 4.5MHz sound sub-carver modulated with
a 1 kHz audio tone. The 30Hz signal is useful for isolating
servo problems in video cassette recorders.
The switch selectable 4.5MHz sound sub-carrier is
modulated by a 1KHz tone and is used to check the sound
circuits and audio/video isolation.