Tektronix 2445, Instruction Manual

Page: 35 / 351

Operating Inform ation—2445 Service
(
4
?) CH 2 SIGNAL OUT Connector—Provides an output
signal that is a normalized representation o f the
Channel 2 input signal. The output amplitude into a
1-M£2 load is approximately 20 mV per division
of input signal. Into a 50-£2 load, the output ampli­
tude is approximately 10 mV per division o f input
signal.
(45) EXT Z-AXIS IN Connector—Provides an input con­
nection point to apply external Z-axis modulation
signals to the Z-Axis Am plifier. Either the sweep or
the X-Y display may be intensity modulated. Positive­
going signals decrease the intensity. From dc to
2 MHz, an input-signal amplitude o f +2 V w ill blank
a maximum-intensity trace; from 2 MHz to 20 MHz,
an input-signal amplitude o f +2 V w ill produce
noticeable modulation on a normal-intensity trace.
Modulating signals w ith fast rise and fall times produce
the most abrupt intensity changes. External Z-axis
signals must be time related to the displayed signal
frequency to obtain a stable intensity-modulation
pattern on the crt.
(46) Fuse Holder—Contains the ac power-source fuse.
(
4 7
) Detachable Power Cord Receptacle—Provides the
connection point fo r the ac power source to the
instrument.
(48) LINE VOLTAGE SELECTOR Switch-Selects the
nominal instrument operating voltage range. When
set to 115V, the instrument operates from a power-
source voltage having a range o f 90 V to 132 V ac.
Set to 230V, the instrument operates on an input-
voltage range of 180 V to 250 V ac.
( 4 ^ Mod Slots—Contain the identification numbers o f any
installed instrument modifications.
READOUT DISPLAY
The Readout System provides an alphanumeric display
o f information on the crt along w ith the analog waveform
display. The readout is displayed in tw o rows o f 32 char­
acters each. One row is w ithin the top graticule division,
and the other row is w ithin the bottom graticule division.
2-13
Figure 2-7. Rear-panel controls and connectors.