Trigger Sensitivity; Single Sweep Mode; Trigger Level Control Range; Mhz Noise Rej Trigger Sensitivity - Tektronix 2246 1Y Service Manual

Performance Check Procedure —2246 1Y and 2246 Mod A Service
g. Move test signal from CH 1 to the CH 2 input.
h. Set leveled sine-wave generator output to pro­
duce a 1.0 division display amplitude at 100 MHz.
i. CHECK—that a stable display can be obtained.
(The Trigger LEVEL control may be adjusted to
improve the display stability.)
j. Repeat procedure for the CH 3 and CH 4 (turn on
the appropriate Vertical MODE and move the test
signal as required).

5. 100 MHz NOISE REJ Trigger Sensitivity

a. Move test signal to the CH 1 input.
b. Set Vertical MODE to CH 1 (others off).
c. Remove the 2X BNC attenuator from the test sig­
nal path.
d. Set Leveled Sine-Wave Generator output for a
2.2 division display amplitude at 100 MHz.
e. CHECK—that the display is stably triggered with
NOISE REJ Trigger CPLG.

6. Single Sweep Mode

a. Set:
Horizontal MODE
ASEC/DIV
A/B SELECT
b. Remove the 10X and 2X BNC attenuators from
the test signal path.
c. Set leveled sine-wave generator output to pro­
duce a 7.0 division display amplitude at 50 kHz.
d. Add a 10X and a 2X BNC attenuator before the
5 0 -n BNC termination. (Display should stably
trigger with AUTO LEVEL finding the correct trig­
ger level setting.)
4-16
e. Set:
A Trigger MODE
Trigger MODE
f.
g.
h.

7. Trigger LEVEL Control Range

a.
b.
c.
A
10 p.s
d.
A Trigger
e. Set leveled sine-wave generator output for a sta­
f.
g. CHECK—that the CH 1 signal display amplitude is
h.
CH 1 Input COUPLING
CHECK—that the Trigger READY LED turns on and
remains on.
Set:
A INTEN
CH 1 Input COUPLING
CHECK—that the TRIG' D LED flashes, and the
READY LED turns off after a single sweep and
readout display occurs when the Input COUPLING
switches to DC.
Set:
Trigger MODE
Trigger LEVEL
A INTEN
Remove 10X and 2X BNC attenuators from the
test signal path.
Increase leveled sine-wave generator output
level until a stably triggered display is just
obtainable.
Set Trigger LEVEL fully CW.
ble display (if necessary).
Set CH 1 VOLTS/DIV to 1 V.
four divisions or more (p e ak-to -p e ak). Note that
the signal is not triggered.
Disconnect the test setup from the 2246 1Y or
2246 Mod A.
NORM
GND
SGL SEQ
3/4 fully CW
DC (see
CHECK below)
AUTO (not
AUTO LEVEL)
Fully CCW
For a good
viewing
intensity
REV OCT 1991