Tektronix 3A1 Instruction Manual page 5

SECTION 1
CHARACTERISTICS
General
The Type 3Al Dual-Trace Amplifier plug-in unit is de-
signed to operate in Tektronix 560-Series Oscilloscopes. The
unit has two identical amplifier channels with a switching
circuit that can select independent operation of either chan-
nel, switch back and forth between channels either at an
internally set chopping rate or on alternate sweeps, or
select the algebraic sum of the two inputs.
OPERATING CHARACTERISTICS
Deflection Factor
Each channel has ten deflection factors from 0.01 volts/civ
to 10 volts/div. in a 1, 2, 5 sequence. Accuracy is —+3%
of indication. Each channel has a variable attenuator which
may be used to introduce a continuously variable attenuation
to a maximum of 2.5 X the indicated deflection factor.
A warning indicator lights when the variable attenuator is
not in the calibrated position.
Frequency Response
DC to at least 10 MHz at —3 dB
Equal to or less than 35 nanoseconds
Input Characteristics
Approximately 1 megohm, paralleled by 47 pF (47 x 10°?
AC or DC coupling of signals may be selected for either
channel. A 0.1 uF capacitor limits low-frequency response
to about 2Hz on AC coupling.
Channel 1 only: Channel 2 will not operate.
Channel 2 only: Channe! 1 will not operate.
Alternate: Electronic switching between channels at the
end of each sweep.
Chopped: Electronic switching between channels at a rate
of about 100 kHz, with a 5 ysec sample of each channel.
Blanking occurs while switching is taking place.
Added: The algebraic sum of both signals is displayed.
When the channel 1 signal is inverted, the difference is
Triggering
An internal signal for triggering is fed from the Type 3Al
through the indicator unit to the time-base plug-in unit.
Trigger signals may be supplied from channel 1 only, or
from channel 1 and channel 2, depending on which
channel is displayed.
Mechanical Features
Construction: Aluminum alloy chassis
Accessories
Information on accessories for use with this instrument is
included at the rear of the mechanical parts list.