TM 11-6625-2735-14-1
Now, pin 3 of U600 should have a low auto gate voltage.
B DLY’D Sweep and Logic
Check TP572 for approximately 0 volt. Check pin 16 of
U600 for approximately 0 volt. Check pin 17 of U600 for
The A Sweep and A INTEN sweep should be working
approximately –0.7 volt. Check pin 6 of U600 for ap-
properly before starting this procedure. Remove all exter-
proximately +4.8 volts. Check pin 3 of U600 for ap-
nal signals to the instrument, set TIME/DIV to 1 ms (lock
knobs), set HORIZ DISPLAY to B DLY’D and set TRIG
proximately –0.2 volt. Install Q574 and check the collec-
tor of Q984 for a repetitive sweep waveform.
MODE to AUTO.
1. Remove Q574 from its socket. Check the collector of
A INTEN Sweep and Logic
Q922 for approximately +14.5 volts. Check the base of
Remove all external signals to the instrument, set
Q792 for approximately –5 volts. Check the collector of
TIME/DIV to 1 ms (lock knobs), set HORIZ DISPLAY to A
Q792 for approximately +1.2 volts. Check TP802 for
INTEN and set TRIG MODE to AUTO.
approximately 0 volt. Check TP826 for approximately
–1.8 volts. Check TP996 for approximately –3.7 volts.
Check the collector of Q984 for approximately +14 volts.
1. Remove Q572 from its socket. This will cause the A
Intensified Sweep Generator (A Sweep), which normally
should be in operation, to stay at a Iow voltage level. Check
the collector of Q922 for approximately +0.3 volt. Check
the collector of Q1014 for approximately +16.4 volts.
Check the collector of Q984 for approximately +14 volts.
The A Sweep holdoff should now be in a reset
condition. Check TP588 for approximately –4 volts.
Check the emitter of Q644 for approximately 0 volt.
When Q572 was removed from its socket, pin 16 of U600
went positive, which is the equivalent of a holdoff start
pulse. Check pin 16 of U600 for approximately +2.5 volts.
Check pin 17 of U600 for approximately +1.7 volts. Check
TP572 for approximately
0 volt. Check pin 3 of U600 for
approximately +0.2 volt.
2. Install Q572 and remove Q574 from its socket. This
will cause only the A Intensified Sweep Generator, (which
normally should be in operation) to stay at a start (high)
voltage level. Check the collector of Q922 for ap-
proximately +13.9 volts.
At this point, the A Sweep holdoff should be at a high
voltage level. Check TP588 for approximately +2 volts.
Check the emitter of Q644 for approximately +4.3 volts.
Pin 3 of U600 should now have a low auto gate voltage.
Check TP572 for approximately 0 volt. Check pin 16 of
U600 for approximately
0 volt. Check pin 17 of U600 for
approximately –0.7 volt. Check pin 6 of U600 for ap-
proximately +4.8 volts. Check pin 3 of U600 for ap-
proximately –0.2 volt. Install 0574 and check the collector
of Q922 for a repetitive sweep waveform.
2. Install Q574 and remove Q572. Check the collector
of Q922 for approximately +0.2 volt. Check the base of
Q792 for approximately –2 volts. Check the collector of
Q792 for approximately –0.7 volt. Check TP802 for ap-
proximately
0 volt. Check TP826 for approximately
–3.8 volts. Check TP996 for approximately –1.7 volts.
Check the collector of 0984 for approximately 0.2 volt.
Install Q572 and check the collector of Q984 for a
repetitive sweep waveform.
MIX Sweep and Logic
The A Sweep, A INTEN Sweep and B DLY’D Sweep
should be working properly before starting this
procedure. Remove all external signals to the Instrument,
set ATIME/DIVto 1 ms, unlock knobs and set BTIME/DIV
to 0.1 ms, set HORIZ DISPLAY to MIX, set TRIG MODE to
AUTO and set B TRIGGER SOURCE to STARTS AFTER
DELAY.
Compare the waveform obtained at pin 10 of J5 against
the waveform at the collector of Q922 and check for
similarity. Check TP996 for a delayed gate, with an
amplitude of appoimately —1.7 volts, that occurs during
the run down ramp on the collector of Q922. The time
position of the delayed gate can decontrolled with DELAY
TIME POSITION. Check the collector of Q984 for a fast
ramp waveform that occurs during a slow ramp waveform.
The fast ramp waveform runs down at a rate set by the B
TIME/DIV control and is positioned in time by the DELAY
TIME POSITION control.
4-17
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