Tektronix 2465B Operator's Manual

Controls, Connectors, and Indicators
jnrMj* Select the
Coupling and Channel 2 and indicate the selection made. If the
Buttons and upper Channel 1 and Channel 2 Input Coupling buttons
Indicators are both pressed together, the instrument automatically
performs a dc balance of Channel 1 and Channel 2
vertical circuitry.
1 MQ AC Input signal is capacitively coupled to the vertical
attenuator. The dc component of the input signal is
blocked. The low-frequency limit (-3 dB point) is
10 Hz or less when using either a IX probe or a
coaxial cable and is 1 Hz or less when using a
properly compensated 10X probe.
Only with the available Television/Video (TV)
enhancement, the CH 2 input has a back porch
clamp for composite video signals. When the input
coupling is AC, pressing the upper button activates
the clamp and displays "TVC in the readout. The
clamp locks the back porch feature of the video
signal to a constant level and eliminates drift, hum.
and tilt, despite changes in signal amplitude and
average luminance levels. Pressing the lower button
restores AC coupling and turns off the clamp.
1 MQ GND The input of the vertical amplifier is grounded to
(2 identical provide a zero (ground) reference-voltage display.
positions) Input resistance is 1 M9. to ground. This input
selection allows precharging of the input-coupling
capacitor to prevent a sudden shift of the trace if AC
input coupling is selected later. The input signal is
not grounded. If the input coupling of a channel
selected as an A-Trigger source is set at GND, the A
Sweep free runs. However, when A TRIGGER
SOURCE is set to VERT and the Add vertical display
is selected, the sweep free runs only if both Channel
1 and the Channel 2 input couplings are set to GND.
While power is off, coupling is at 1 MQ GND.
1 MQ DC All frequency components of the input signal are
coupled to the vertical. Input resistance is 1 MQ
to ground.
50 Q DC All frequency components of the input signal are
coupled to the vertical, with the input terminated by
50 Q to ground. If excessive signal is applied to
either the CH 1 or the CH 2 input connector while
50 Q DC input coupling is selected, input coupling will
revert to 1 MQ GND and a CRT readout will indicate
the overloaded condition. Changing the input
coupling of the affected channel removes the
overload message.
2465B/2455B/2445B Operators
5-9

Tektronix 2465B Specifications

General

Bandwidth	400 MHz
Channels	4
Vertical Sensitivity	2 mV/div to 5 V/div
Maximum Input Voltage	400 V (DC + peak AC)
Display	CRT
Trigger Modes	Auto, Normal, Single
Time Base Range	500 ps/div to 0.5 s/div
Rise Time	875 ps
Power Supply	48 to 440 Hz
Dimensions	495 mm