Tektronix TG700, Руководство пользователя

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HD3G7 HD 3 Gb/s SDI Video Generator
The zone plate dependent parameters are discussed here, in the order in which
they appear below the pattern control parameter, when using the down (
▼ ) arrow
button to scroll through the parameter menu. The Custom–1 and Custom–2 signal
selections do not have pattern control parameters, and start with the Zone Plate
Amplitude Parameter.
Zone Plate Amplitude
Parameter
Display name: ZP Amplitude
Units: mV
Use this parameter to adjust the zone plate signal amplitude from 0.0 mV to
798.0 mV, in 0.5 mV increments. The default value is 700 mV.
K
X
Parameter Display name: KX (H Freq.)
Units: cycles/active picture height (c/aph)
K
X
denotes the initial constant horizontal frequency of the pattern. To see the
effects of changing this coef fi cient, set a waveform monitor to view the video
lines. Note that the units are cycles per active picture height. The number of
cycles in a line will depend on the width-to-height aspect ratio of the active
format. For example, K
X
= 9.0 will result in approximately 12 cycles per line in a
format with a 4:3 aspect ratio; the same setting will yield about 16 cycles per line
when the ratio is 16:9.
To estimate the equivalent absolute frequency of the sine wave (i.e., to convert
from c/aph to c/s, or Hz), use the formula
where
R
aspect
= the aspect ratio (width ÷ height)
N
lines
= the number of lines per frame
f
frame
= the frame rate
R
l:av
= the ratio of line length to the length of the active video
The maximum frequency is (±) half of the active format’s sampling frequency. In
formats that use a 74.25 MHz clock, for example, the maximum value of KX will
correspond to a sine frequency of 37.1 MHz.
The Horizontal Sine zone plate, for example, is a “K
X
-only” zone plate. (See
Figure 3-77.)
TG700 TV Signal Generator Platform User Manual 3–155