Figure 3-1.
Video level measuring scales
a. These scales were designed to present a standard video level of 1 volt
peak-to-peak.
The scales are called Institute of Electrical and Electronics
Engineers (IEEE) or Institute of Radio Engineers (IRE) scales.
They are divided
into 140 units which equal 1-volt peak-to-peak of composite video.
b. This 1-volt signal contains 0.714 volt video information (0 to 1000 units)
and 0.286 volt sync (0 to -40 units).
3.
The three scales in figure 3-1 illustrate the various points to be monitored
in a system. Use operating scale No. 1 for points in the system where sync is not
added.
Operating Scale No. 2 is used in the system to measure composite signal
(sync added).
Operating Scale No. 3 is used at transmitter locations to relate
IEEE units to depth of modulation.
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