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MAINTENANCE
Model
2001
detector can be used to recover the signal at levels down to
approximately -40dBm. Below this level an RF amplifier
or sensitive receiver (spectrum analyzer) must be used.
Allowability error
i s
rt0.5dB to 500 MHz, r t l d b to 1000
MHz, and rt2dB to 1400 MHz. This error is that produced
by the step attenuator alone and does not include the basic
flatness or the vernier attenuator error.
5.3.12
SWEEP TlME CHECK (Horizontal Output Check)
Connect the horizontal output of the sweep generator to
the oscilloscope vertical input. Adjust the oscilloscope con-
trols for an internally generated, automatic, line-triggered
sweep of 2msIcm and a vertical sensitivity of 2VIcm.
Adjust the sweep generator SWEEP TI ME selector to L l NE
lock and ensure that the TRIG/RECUR switch i s in the
RECUR position. Adjust the oscilloscope vertical position,
horizontal position, and trigger level t o obtain the wave-form
shown in Figure 5-6.
WAIT TlME
(LINE POSITION ONLY1
16ms
(B
60
HI
20 m s aB 50
Hx
Figure 5-6. Scope Horizontal Output
Adjust the sweep generator SWEEP TlME selector to .I-.O1
position. Ensure that the VARIABLE MANUAL control i s
fully clockwise. The wait time should disappear and the
sweep time should be less than 10ms with approximately
equal sweep time and retrace time periods.
Adjust the
oscilloscope time base to 50msIcm.
Adjust the sweep
generator VAR IABLEIMANUAL control fully counterclock-
wise.
The sweep time should be more than 100ms with
approximately a 1 0 : l ratio between the sweep and retrace
time periods.
NOTE: The retrace time period remains constant within
any one SWEEP TlME range setting and the VARIABLE/
MANUAL control varies the sweep time period. With the
VARIAB LEIMAN UAL control fully clockwise the sweep
and retrace times are both approximately 0.01 seconds.
With the control fully counterclockwise the sweep time be-
comes approximately 0.1 seconds and the retrace time re-
mains 0.01 seconds. On the next lower range ( I - . l ) the
retrace time would remain 0.1 sec and the sweep time would
vary from 0.1 t o 1 second.
Repeat these checks for the 1-.I, 10-1, and 100-10 sec
positions of SWEEP TI ME selector switch. Adjust oscillo-
scope time base as necessary to ensure that the VARIABLE1
MANUAL control will adjust the sweep time from faster
than the maximum t o slower than the minimum specifica-
tions for each range.
Adjust the SWEEP TlME selector t o MANUAL and adjust
the VARIABLEIMANUAL throughout its range.
A
DC
voltage should be present that i s variable from -8V, L 5 V ,
with the control fully counterclockwise t o +8V, f . 5 V ,
with the control fully clockwise.
Adjust the SWEEP TlME selector t o the .I-.O1 position and
set the TRIGIRECUR switch t o TRIG. The sweep should
now be disabled.
Moving the switch to the upper most
position (spring loaded position) and releasing i t should
produce one complete sweep cycle.
NOTE: The triggered mode of operation i s only possible in
the variable rate positions and will not operate in the LINE
lock position of the SWEEP TlME selector.
5.3.13
MARKER SYSTEM CHECK
Connect the equipment as shown in Figure 5-4. Adjust the
sweep generator and oscilloscope controls to obtain the
display shown in Figure 5-5. The actual control settings
would be the same as in paragraph 5.3.2.
NOTE: The following performance check is for a 50 MHz
harmonic marker.
Specifications, with the exception of
spurious markers, are the same for either single frequency or
harmonic type markers and the procedure for verification of
performance does not differ.
Single frequency markers should have no spurious markers
throughout the swept range. Harmonic type markers may
or may not have small spurious markers at one half or one
third the specified marker interval.
MARKER SIZE
Observe the markers and ensure they are of equal amplitude
throughout the range. Repeat this check for bands
2
and
3.
MAINTENANCE
detector can be used to recover the signal at levels down to
approximately -4OdBm.
Below this level an RF amplifier
or sensitive receiver (spectrum analyzer) must be used.
Allowability error is ±0.5dB to 500 MHz, ± ldb to 1000
MHz, and ±2dB to 1400 MHz. This error is that produced
by the step attenuator alone and does not include the basic
flatness or the vernier attenuator error.
5.3.12
SWEEP TIME CHECK (Horizontal Output Check)
Connect the horizontal output of the sweep generator to
the oscilloscope vertical input. Adjust the oscilloscope con-
trols for an internally generated, automatic, line-triggered
sweep of 2ms/cm and a vertical sensitivity of 2V /cm.
Adjust the sweep generator SWEEP TI ME selector to LI NE
lock and ensure that the TRIG/RECUR switch is in the
RECUR position. Adjust the oscilloscope vertical position,
horizontal position, and trigger level to obtain the wave-form
shown in Figure 5 6
.~
~
+8V
/
(
..
V\
J 1\
\1
\
-\\
.J
\1
\
J
,
'\
1\
\1
\\
\
j
\
' "
OV
-8V
~,- tw~
+:::::
SITION ONL VI
TIME
TIME
16m • • 6 O H z _
W
(LINE PO
20m • • SO Hz
""
j
V
Figure 5-6. Scope Horizontal Output
~
~
Adjust the sweep generator SWEEP TIME selector to .1-.01
position. Ensure that the VARIABLE MANUAL control is
fully clockwise.
The wait time should disappear and the
sweep time should be less than 10ms with approximately
equal sweep time and retrace time periods.
Adjust the
oscilloscope time base to 50ms/cm.
Adjust the sweep
generator VAR IABLE/MANUAL control fully counterclock-
wise.
The sweep time should be more than lOOms with
approximately a 10: 1 ratio between the sweep and retrace
time periods.
NOTE:
The retrace time period remains constant within
anyone SWEEP TIME range setting and the VARIABLE/
MANUAL control varies the sweep time period. With the
5-6
Model 2001
VA R I AB LE/MAN UA L control fu lIy clockwise the sweep
and retrace times are both approximately 0.01 seconds.
With the control fully counterclockwise the sweep time be-
comes approximately 0.1 seconds and the retrace time re-
mains 0.01 seconds. On the next lower range (1-.1) the
retrace time would remain 0.1 sec and the sweep time would
vary from 0.1 to 1 second.
Repeat these checks for the 1-.1, 10-1, and 100-10 sec
positions of SWEEP TIME selector switch. Adjust oscillo-
scope time base as necessary to ensure that the VAR lAB LE/
MANUAL control will adjust the sweep time from faster
than the maximum to slower than the minimum specifica-
tions for each range.
Adjust the SWEEP TIME selector to MANUAL and adjust
the VARIABLE/MANUAL throughout its range.
A DC
voltage should be present that is variable from -BV, ±.5V,
with the control fully counterclockwise to +BV, ±.5V,
with the control fu Ily clockwise.
Adjust the SWEEP TIME selector to the .1-.01 position and
set the TRIG/RECUR switch to TRIG. The sweep should
now be disabled.
Moving the switch to the upper most
position (spring loaded position) and releasing it should
produce one complete sweep cycle.
NOTE: The triggered mode of operation is only possible in
the variable rate positions and will not operate in the LI N E
lock position of the SWEEP TIME selector.
5.3.13
MARKER SYSTEM CHECK
Connect the equipment as shown in Figure 5-4. Adjust the
sweep generator and oscilloscope controls to obtain the
display shown in Figure 5-5.
The actual control settings
would be the same as in paragraph 5.3.2.
NOTE: The following performance check is for a 50 MHz
harmonic marker.
Specifications, with the exception of
spurious markers, are the same for either single frequency or
harmonic type markers and the procedure for verification of
performance does not differ.
Single frequency markers should have no spurious markers
throughout the swept range. Harmonic type markers may
or may not have small spurious markers at one half or one
third the specified marker interval.
MARKER SIZE
Observe the markers and ensure they are of equal amplitude
throughout the range. Repeat this check for bands 2 and 3.
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