Tektronix TDS 420A, Service Manual, Page: 48 / 288

Typical Characteristics
1- 26
TDS 420A, TDS 430A & TDS 460A Service Manual
Table 1- 19: Typical Characteristics — Triggering System (Cont.)
Name Description
Width, Minimum Pulse and Rearm, Events
Delay
6
5 ns
1
The trigger position errors are typically less than the values given here. These values are for triggering signals having a
slew rate at the trigger point of
±
0.5 division/ns.
2
The waveform interval (WI) is the time between the samples in the waveform record. Also, see the footnote for the
characteristics
Sample Rate Range and Equivalent Time or Interpolated Waveform Rates in Table 1 - 4 on page 1 - 9.
3
The minimum sensitivity for obtaining a stable trigger. A stable trigger results in a uniform, regular display triggered on
the selected slope. The trigger point must not switch between opposite slopes on the waveform, and the display must not
“roll” across the screen on successive acquisitions. The TRIG’D LED stays constantly lighted when the SEC/DIV setting
is 2 ms or faster but may flash when the SEC/DIV setting is 10 ms or slower.
4
See the characteristic Sensitivity, Edge-Type Trigger, DC Coupled in Table 1- 12, which begins on page 1- 18.
5
The maximum frequency for a delaying events input.
6
The minimum pulse width and rearm width required for recognizing a delaying event.
Table 1- 20: Typical Characteristics — Data Handling
Name Description
Time, Data-Retention, Nonvolatile
Memory
1,2
Internal batteries, installed at time of manufacture, have a life of
≥
5 years when operated
and/or stored at an ambient temperature from 0
_
C to 50
_
C. Retention time of the
nonvolatile memories is equal to the remaining life of the batteries
Nonvolatile Memory Save Time 10 seconds
Floppy Disk Drive Capacity 3.5 in. floppy disk, 720 KB or 1.44 MB, compatible with DOS 3.3 format for storing
waveforms, hard copies, and instrument setups
1
The time that reference waveforms, stored setups, and calibration constants are retained when there is no power to the
oscilloscope.
2
Data is maintained by lithium poly-carbon monofluoride.