Tabor 8020, Руководство пользователя

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CONTROL POSITION
Frequency As required by procedure
Amplitude 1.00 V
Offset 0.00 V
Sweep Stop 2.0 MHz
Sweep Time 1 S
Sweep Marker 10 MHz
Operating Mode Normal (all lights off)
Trigger Mode Continuous (all lights off)
Output Squarewave
7-3. ADJUSTMENT PROCEDURE
7-3-1. Power Supply Adjustment
Equipment: DMM
1 . Set DMM to DC measurements. Measure and record the
-15 V supply voltage with 10 mV resolution.
2 . Adjust R4 so that the +15 V supply would be the same as
the voltage level recorded in step 1.
7-3-2. Distortion Adjustment
Equipment: Distortion Analyzer, Oscilloscope
1 . Change 8020 Output setting to Sine.
2 . Change 8020 Frequency setting to 2.000 KHz.
3 . Set the oscilloscope to 1V/Div. and DC coupling and adjust
the trace line vertically to be exactly at the center of the screen
(0 V).
4 . Connect the OUTPUT terminal to the oscilloscope and ad-
just R172 to get a symmetrical waveform, about the 0V line,
on the screen.
5 . Disconnect the OUTPUT from the oscilloscope and con-
nect the OUTPUT to the distortion analyzer.
6 . Adjust R115 and R129, repeatedly, until the distortion
reading on the analyzer is less than 0.2%. Note that each one
of these resistors contribute a small amount to the distortion
correction. It is up to the service technician to find the most
effective sequence to perform this step.
7 . Disconnect the OUTPUT from the analyzer and repeat
steps 3 and 4.
7-3-3. Frequency Adjustment
Equipment: Counter, Oscilloscope, 50 ohms feedthrough
termination
1 . Change 8020 operating mode setting to VCO.
2 . Change 8020 Frequency setting to 1.990 KHz.
3 . Connect the OUTPUT terminal to the universal counter
input. Terminate counter input with 50 ohms feedthrough
termination.
4 . Set counter to frequency measurements and adjust R29 for
a reading of 1.990 KHz +/-10 Hz on the counter display.
5 . Change 8020 Frequency setting to 19.90 KHz and check
that the reading on the counter is 19.90 KHz +/-30 Hz. If read -
ing is not within the specified value readjust R29 so that the
error in 1.990 KHz and 19.90 KHz is the same.
6 . Change 8020 Frequency setting to 2.00 MHz.
7 . Set counter and adjust C38 to give a reading of 2.00 MHz
+/-30 KHz on the counter display.
8 . Set the oscilloscope to 20 mV/Div. and DC coupling and
adjust the vertical trace line to be exactly at the center of the
screen (0 V). Connect a 10:1 high frequency probe,with a
very short ground lead, to the junction to TP7. Adjust the ver-
tical gain of the oscilloscope so that the peak to peak ampli-
tude on the screen will be exactly 6 divisions. Change 8020
frequency setting to 15.00 MHz. Select C56 and adjust C60
until peak to peak trace is 6 div/-1 small division.
Note that the trace should be vertically symmetrical about the
0 V line.
9 . Readjust C60 to give a reading of 15.00 MHz +/-300 KHz
on the counter display.
10 . Change 8020 Frequency setting to 2.00 MHz.
11 . Check with counter if reading is 2.00 MHz +/-30 KHz. If
reading is not within the specified value readjust C38.
12 . Repeat steps 9 through 11 until best accuracy is achieved.
13 . Change 8020 Frequency setting to 199.0 KHz.
14 . Set counter and select C44 (approximately 330PF) to give
a reading of 199.0 KHz +/-3 KHz on the counter display.
15 . change 8020 Frequency setting to 1.990 MHz.
16 . Select C41 (approximately 47PF) to give a reading of 1.990
MHz +/-30 KHz on the counter display.
7-3-4. Low Frequency Adjustment
Equipment: Counter
1 . Change 8020 Frequency setting to 10.00 Hz.
2 . Connect the 8020 OUTPUT terminal to the counter.
3 . Adjust R59 to 10.00 Hz +/-.1 Hz.
7-3-5. Low Frequency Distortion Adjustment
Equipment: Distortion analyzer, Counter
1 . Change 8020 Frequency setting to 10.00 Hz.
2 . Change 8020 Output setting to sine.
3 . Connect 8020 OUTPUT terminal to the distortion analyzer
input.
4 . Adjust R44 for minimum distortion.
Adjustments Model 8020
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