Tektronix 7D14, Instruction Manual

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Operating Instructions— 7D 14
EXT GATE/MONI- BSM connector for external gate in ­
TOR Connector put or time marker output as
selected by MEASUREMENT
INTERVAL pushbuttons.
Display Time Controls
DISPLAY TIME Variable control to set the length of
time the reading will be displayed
after the count is made and before
the next measurement is taken. Dis­
play time can be varied from 0.1
second to five seconds. °° (infinite)
position (fully clockwise) provides
continuous display until reset by an
external signal or by pressing the
RESET pushbutton.
RESET Pushbutton: Manually resets the
counter to zero.
Pin-jack connector: Provides input
for external signal to reset the
counter to zero.
Reference Frequency/Channel B Controls
REF FREQ/CH B Pushbuttons that select the func­
tion of the EXT IN/MONITOR
connector.
INT 1 MHz
(Internal 1 mega­
hertz)
Selects 1 MHz signal from internal
crystal oscillator at MONITOR con­
nector.
EXT IN
(external
input)
Selects external input to Channel B
for an external timing standard, or
for signal input for ratio measure­
ments.
Trigger Controls
LEVEL/SLOPE Selects the amplitude point and
slope on trigger signal where
counter is triggered (VAR push­
button pressed). When the indicator
line on the outer ring is to the left
of center, the counter is triggered
on the positive-going slope of the
input signal as shown by the
positive-going edge symbol. To the
right of center, the counter is trig­
gered on the negative-going slope of
the input signal as shown by the
negative-going edge symbol.
PRESET
Pushbutton that selects a fixed trig­
ger point at the zero-volt level on
the positive-going slope (LEVEL/
SLOPE control inoperative).
VAR Pushbutton to allow manual selec­
tion of trigger level and slope with
the LEVEL/SLOPE control.
INPUT SENS/P-P Rotary switch that selects internal
VOLTS
or external signal input to trigger
counter and selects sensitivity.
50 Ω Input signal provided from CH A
INPUT connector at 50-ohm input
impedance.
1 V: Minimum signal amplitude
must be one volt or greater.
100 mV: Minimum signal ampli­
tude must be 100 mV or greater.
1 MΩ Input signal provided from CH A
INPUT connector at one-megohm
input impedance.
100 mV: Minimum signal ampli­
tude must be 100 mV or greater.
1 V: Minimum signal amplitude
must be one volt or greater.
10 V: Minimum signal amplitude
must be 10 volts or greater.
TRIG SOURCE Input signal provided from the indi­
cator oscilloscope trigger pickoff
circuitry. (This mode of operation
enables simultaneous counting and
CRT
display of a signal. For more
information, see Counting a Dis­
played Signal.)
BW (bandwidth) Pushbutton switches that select the
bandwidth of the trigger input cir­
cuits (affects signals from internal
TRIG SOURCE and CH A INPUT
connector).
525 MHz: Selects full bandwidth
capability.
5 MHz: Limits upper bandwidth to
about 5 megahertz (—3 dB
point).
COUPLING
Pushbutton switches that select the
method of coupling the signal from
the CH A INPUT connector to the
trigger circuits (does not affect sig­
nals from internal TRIG SOURCE).
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