Tektronix 1720

Operating Instructions
1720/1721
2–3
5. BARS
A momentary contact push-button switch that toggles between correct gain for
displaying 75% and 100% amplitude color bar signals, using a single set of
vector targets. Burst targets for both 75% and 100% amplitude color bars are on
the graticule. Back lighted nomenclature, with rectangular indicators, lights to
indicate that the 1720/1721 is set up to measure color bars.
6. PAL/+V (PAL Only)
A momentary contact push-button switch that selects either PAL (±V) or +V
only for the phase displays. +V overlays +V with –V on the +V Axis for
alternate line comparisons. Back lighted nomenclature, with rectangular
indicators, lights to indicate that either standard PAL or overlayed + and –V is
being displayed.
7. (control)
A continuously-variable control with 360° range to set the phase of the decoder
reference.
8. FOCUS
A 270° rotation potentiometer that is adjusted for display definition.
9. SCALE
A 270° rotation potentiometer that controls the level of graticule illumination.
10.
INTENS
A 270° rotation potentiometer that controls display brightness.
11. AUXILIARY
Toggles between AUXILIARY and independent operation. In the AUXILIARY
mode, a Line Strobe (to blank the 1720/1721 crt, for line selection) and data to
actuate the front-panel setup is accepted from a companion 1730-Series. Back
lighted nomenclature and a rectangular indicator both light to indicate that the
instrument is under AUXILIARY control.
PHASE
DISPLAY
MISCELLANEOUS