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MAINTENANCE
Model
2001
WITH NO INPUT, ADJUST HORIZONTAL POSITION
TO SET THE DO^ AT THE
5 ~ r n ICENTERI LINE
monic markers on the scope display. Residual FM can be
read directly on the scope display by noting the amount of
ADJUST HORIZONTAL SENSITIVITY
iitter of the marker. ( A iitter of 0.2cm would be equal to
I
FOR A DISPLAY WlDTH OF EXACTLY
+
5.2
crn
.
.
20 kHz).
Change SWEEP TIME selector from LlNE to the 0.1
-
0.01
position and again read the marker jitter. The additional
jitter in this position represents the line related residual.
Maximum allowable jitter is 15 kHz. Alternate Method t o
read residual FM is with a spectrum analyzer.
5.3.5 FREQUENCY DRIFT
Return SWEEP TIME selector t o LlNE and again calibrate
the display's sweep width t o 1 MHz. Position the marker to
the exact center of the oscilloscope display and read fre-
quency drift directly from the scope display by noting the
change in the markers position with time. Each centimeter
represents 100 kHz. When reading drift over long periods of
time, calibrate the display sweep width t o 5 MHz, using the
I
BAND 1
0
I
250
I
500
BAND 2
450
700
950
BAND 3
900
1150
1400
Figure 5-5. RF Detector Display
T o check the minimum frequency on band 1, set BAND t o
1 and frequency dials (use either SIS or A F MODE) t o
sweep approximately 0 t o 10 MHz. Turn on the 10 MHz
harmonic marker and locate the first marker on the right of
zero lock-in point. Turn on the 1 MHz harmonic marker
and count down to 1 MHz. The detected output must be
leveled down to the 1 MHz marker at all settings of the
OUTPUT vernier.
5.3.3 MINIMUM SWEEP WI DTH CHECK
Set MODE t o A F and adjust SWEEP'WIDTH t o exactly 1
MHz (use 1 MHz markers). Adjust the MARKER WIDTH
t o produce a marker approximately 200 kHz wide. Next,
adjust the SWEEP WIDTH to minimum.
The 200 kHz
wide marker should cover the entire scope display. Repeat
the above check for bands 2 and 3, readjusting sweep
width and center frequency as required. The minimum
sweep width is less than 200 kHz on all bands.
5.3.4 RESIDUAL FM CHECK
Readjust SWEEP WIDTH to produce a calibrated frequency
display
of
exactly
1 MHz
full scale.
Adjust
CENTER
FREQUENCY control to center one of the 1 MHz har-
1 MHz harmonic marker. Next turn off the 1 MHz marker
and turn on the 50 or 10 MHz harmonic markers. Center a
marker on the scope display and read drift as before, except
each centimeter now represents 500 kHz.
Maximum allowable drift is 100 kHz per 5 minutes or 2
MHz per
8
hours, after a one hour warm-up at a constant
ambient temperature, and allowing a 5 minute stabilizing
period after a frequency change.
5.3.6 D I A L ACCURACY CHECK
A F MODE:
Set MODE to AF, BAND to 1, MARKER
WIDTH t o wide and turn on the 50 MHz harmonic marker.
(1 and 10 marker off). Set SWEEP WIDTH t o approximate-
ly 1 t o 2 MHz and adjust CENT FREQ control until the
zero frequency lock-in point is exactly center on the scope
display. Read the error on the frequency scale. Repeat at
each 50 MHz harmonic intervals across the band.
The
allowable error is 2 1 0 MHz.
Repeat check on bands 2 and 3. A n additional frequency
error is produced by the pulling effect of the OUTPUT
vernier on bands 2 and 3, therefore, rotate the OUTPUT
vernier thru its entire range at each 50 MHz check point.
Increasing the SWEEP WIDTH to approximately 5 MHz
will simplify reading. The allowable error on band 2 and 3
is 2% of the indicated frequency.
The accuracy of the SWEEP WIDTH scale can be checked
with the 50 MHz harmonic marker in a similar manner. Set
the actual sweep width to 50, 100, 150, etc., and read the
error on the SWEEP WIDTH scale. Accuracy on band 1 is
MAINTENANCE
WITH NO INPUT, ADJUST HORIZONTAL POSITION
TO SET THE -'DOT" AT THE 5 em (CENTERI LINE
ADJUST HORIZONTAL SENSITIVITY
FOR
A DISPLAY WIDTH
OF
EXACTLY
+
5.2em
-
I
/ / " ' "
/ '
~.L_
~
/
ov
O.2V
- I
I
--
O.4V
--
-
O.6V
O.IV
-\~
BAND I
lAND
2
BAND 3
I""
o
450
900
~
I
250
700
1150
-
~
i"' "
V
/
500
950
1400
Figure 5-5. R F Detector Display
To check the minimum frequency on band 1, set BAND to
1 and frequency dials (use either
SIS
or
~
F MODE) to
sweep approximately 0 to 10 MHz. Turn on the 10 MHz
harmonic marker and locate the first marker on the right of
zero lock-in point.
Turn on the 1 MHz harmonic marker
and count down to 1 MHz. The detected output must be
leveled down to the 1 MHz marker at a" settings of the
OUTPUT vernier.
5.3.3 MINIMUM SWEEP WIDTH CHECK
Set MODE to
~F
and adjust SWEEP'WIDTH to exactly 1
MHz (use 1 MHz markers). Adjust the MARKER WIDTH
to produce a marker approximately 200 kHz wide. Next,
adjust the SWEEP WIDTH to minimum.
The 200 kHz
wide marker should cover the entire scope display. Repeat
the above check for bands 2 and 3, readjusting sweep
width and center frequency as required.
The minimum
sweep width is less than 200 kHz on a" bands.
5.3.4 RESIDUAL FM CHECK
Readjust SWEEP WIDTH to produce a calibrated frequency
display of exactly
1
MHz full scale.
Adjust CENTER
FREQUENCY control to center one of the 1 MHz har-
5-4
Model 2001
monic markers on the scope display. Residual FM can be
read directly on the scope display by noting the amount of
jitter of the marker. (A jitter of 0.2cm would be equal to
20 kHz).
Change SWEEP TIME selector from LINE to the 0.1 - 0.01
position and again read the marker jitter. The additional
jitter in this position represents the line related residual.
Maximum allowable jitter is 15 kHz. Alternate Method to
read residual FM is with a spectrum analyzer.
5.3.5 FREQUENCY DRIFT
Return SWEEP TIME selector to LINE and again calibrate
the display's sweep width to 1 MHz. Position the marker to
the exact center of the oscilloscope display and read fre-
quency drift directly from the scope display by noting the
change in the markers position with time. Each centimeter
represents 100 kHz. When reading drift over long periods of
time, calibrate the display sweep width to 5 MHz, using the
1 MHz harmonic marker. Next turn off the 1 MHz marker
and turn on the 50 or 10 MHz harmonic markers. Center a
marker on the scope display and read drift as before, except
each centimeter now represents 500 kHz.
Maximum a"owable drift is 1 00 kHz per 5 minutes or 2
MHz per 8 hours, after a one hour warm-up at a constant
ambient temperature, and allowing a 5 minute stabilizing
period after a frequency change.
5.3.6 DIAL ACCURACY CHECK
~F
MODE:
Set MODE to
~F,
BAND to 1, MARKER
WIDTH to wide and turn on the 50 MHz harmonic marker.
(1 and 10 marker off). Set SWEEP WI DTH to approximate-
ly 1 to 2 MHz and adjust CENT FREQ control until the
zero frequency lock-in point is exactly center on the scope
display. Read the error on the frequency scale. Repeat at
each 50 MHz harmonic intervals across the band.
The
a"owable error is
±
10 MHz.
Repeat check on bands 2 and 3. An additional frequency
error is produced by the pulling effect of the OUTPUT
vernier on bands 2 and 3, therefore, rotate the OUTPUT
vernier thru its entire range at each 50 MHz check point.
Increasing the SWEEP WIDTH to approximately 5 MHz
will simplify reading. The a"owable error on band 2 and 3
is 2% of the ind icated frequency.
The accuracy of the SWEEP WIDTH scale can be checked
with the 50 MHz harmonic marker in a similar manner. Set
the actual sweep width
to
50, 100, 150, etc., and read the
error on the SWEEP WI DTH scale. Accuracy on band 1 is
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