Tektronix 2445, Instruction Manual

Page: 15 / 351

Specification—2445 Service
Table 1-1 (cont)
Characteristics
Performance Requirements
VER TICAL DEFLECTION SYSTEM -CHANNEL 3 AND CHANNEL 4 (cont)
Step Response
Rise Time
2.33 ns or less (calculated from bandwidth).3
Channel Isolation
50:1 or greater attenuation o f the deselected channel at 100 MHz
w ith an eight-division input signal.
Input R and C
Resistance
1 M£2 ±1%.a
Capacitance 15 pF ±3 pF.a
Maximum Input Voltage
A
400 V (dc + peak ac);
800 V p-p ac at 10 kHz or less.3
VERTICAL DEFLECTION S Y S T E M -A LL CHANNELS
Low-frequency Linearity 0.1 division or less compression or expansion o f a two-division,
center-screen signal when positioned anywhere w ithin the graticule
area.
Bandwidth Lim iter
Reduces upper 3-dB bandpass to a lim it of 13 MHz to 24 MHz.
Vertical Signal Delay A t least 20 ns of the sweep is displayed before the triggering event
is displayed.3
Chopped Mode Switching Rate Vertical display switches sequentially through the selected channels
at the chop switching rate. If the B SEC/DIV switch is set to sweep
speeds outside the range of 20 /ts per division to 2 jus per division,
the switching rate is 1 MHz ±0.2% (dual-channel cycle rate of
: 500 kHz). If the B SEC/DIV switch is set w ithin the range of 20 /is
I per division to 2 /is per division, the switching rate is 2.5 MHz ±0.2%
(dual-channel cycle rate o f 1.25 MHz). A t all sweep speeds, the
[ chop switching rate is desynchronized w ith the sweep frequency to
I minimize waveform breaks when viewing repetitive signals.3
TRIGGERING
Minimum P-P Signal Am plitude for Stable
Triggering from Channel 1 or Channel 2 Source
DC Coupled
0.35 division from dc to 50 MHz, increasing to 1 division
at 250 MHz.
NOISE REJ Coupled
1.2 divisions or less from dc to 50 MHz, increasing to 3 divisions
at 250 MHz.
AC Coupled
0.35 division from 60 Hz to 50 MHz, increasing to 1 division at
250 MHz. Attenuates signals below 60 Hz.
HF REJ Coupled
0.5 division from dc to 30 kHz.
LF REJ Coupled
0.5 division from 80 kHz to 50 MHz, increasing to 1 division
at 250 MHz.
Perform ance Requirement not checked in manual.
1-4