Net Weight - Tektronix 3A74 Instruction Manual

SECTION 1
CHARACTERISTICS
General Information
The Type 3A74 Four-Trace Amplifier Plug-In Unit is de-
signed for use with all Type 560-Series Oscilloscopes* except
the Type 560 itself. The Type 3A74 contains four independent
amplifier channels. Each channel can be used separately to
produce a single display or electronically switched to pro-
duce multi-trace displays. These features reduce cable switch-
ing to a minimum.
Each amplifier channel has its own input coupling,
attenuator, variable gain, position and mode controls which
permit individual adjustment of each channel for best
measurement conditions.
In multi-trace operation there is a choice of two modes
of operation—chopped or alternate. In the chopped mode
(free-running electronic switching), an internal oscillator
switches the channels sequentially at a free-running rate of
about 500ke. In the alternate mode (triggered electronic
switching) the oscilloscope time-base generator internally
switches the channels at the end of each sweep. Switching
occurs during retrace intervals.
Bandpass
De to 2 mc.
Risetime
0.17 microsecond.
Calibrated Deflection Factors
Nine calibrated steps provided for each channel: 0.02,
0.05, 0.1, 0.2, 0.5, 1, 2, 5, and 10 volts/div. When the
gain is set accurately for the 0.02 volt/div. step, the other
steps will be accurate within 3%
of their respective panel
readings.
Uncalibrated Deflection Factors
Variable controls for each channel permit continuous
uncalibrated adjustments from 0.02 volt/div. up to approxi-
mately 25 volts/div.
Input Impedance
1 megohm +1% paralleled by 47 pf +3%.
*Type 561 Oscilloscopes below serial number 580 must be modified
first to obtain proper multi-trace operation from the Type 3A74. If
your oscilloscope needs to be modified, ask your Tektronix Field
Engineer for Modification Kit No. 040-267. This modification is
not needed in any of the Type RM561 Oscilloscopes because they
are all compatible.
@l
Maximum Allowable Signal Voltage at
Input Connectors
=£600 volts de or peak.
Input Coupling
Selectable AC or DC coupling. In the AC position a
coupling capacitor is inserted, limiting the low-frequency
response to about 2 cps at 3 db down. With a 10X attenuator
probe low-frequency response is extended to 0.2 cps; with
a 100X probe, response is 2 cps.
Operating Modes
Channel 1, 2, 3, or 4 only.
Chopped—Sequential electronic switching of two or more
channels at approximately a 500-ke rate. The input for each
channel is chopped into "on" and "'off'' segments. Thus the
display of each channel is a series of 2-ysec "on" segments.
Alternate—Triggered electronic switching sequentially from
channel to channel during retrace intervals.
Polarity Inversion
Polarity switch for each channel permits inverting the
displayed waveform.
Construction
Aluminum-alloy chassis.
Finish
Photo-etched anodized aluminum front panel.
Net Weight
6 lbs. 4 oz.
Included Accessories
Tektronix
Qty. Part Number Description
4 103-033 Adapter, single binding post fitted
with a BNC plug.
2 070-347 Type 3A74 Instruction Manuals.