HP 654A - 5-28. Balance Checks

Section V Model 654A
5-18. 135 BAL FLATNESS CHECK.
a. Perform the procedure of Paragraph 5-16 steps a
through g with the following changes:
In step a. Set IMPEDANCE to 135 BAL;
In step b. Use the 135 ohm thermal converter
(Table 5-3) which should be connected directly
to both output connectors of the 654A;
In step f. Sweep the 654A over the frequency
range of 10Hz to 5MHz.
b. If the tolerances are not met, first assure that the
75 UNBAL flatness is within tolerance before
troubleshooting the 654A.
5-19. 150 BAL FLATNESS CHECK.
a. Perform the procedure of Paragraph 5-16 steps a
through g with the following changes:
In step a. Set IMPEDANCE to 150 BAL;
In step b. Use the 150 ohm thermal converter
(Table 5-3) which should be connected directly
to both output connectors of the 654A;
In step f. Sweep the 654A over the frequency
range of 10Hz to 5MHz.
b. If the tolerances are not met, first assure that the
75 UNBAL flatness is within tolerance before
troubleshooting the 654A.
5-20. 600 BAL FLATNESS CHECK.
a. Perform the procedure of Paragraph 5-16 steps a
through g with the following changes:
In step a. Set IMPEDANCE to 600 BAL;
In step b. Use the 600 ohm thermal converter
(Table 5-3) which should be connected directly
to both output connectors of the 654A.
In step f. Sweep the 654A over the frequency
range of 10Hz to 1MHz.
b. If the tolerances are not met, first assure that the
75 UNBAL flatness is within tolerance before
troubleshooting the 654A.
5- 21. METER TRACKING ACCURACY CHECK.
a. Connect the equipment as shown in Figure 5-5.
Use an attenuator with known accuracy at 10kHz,
and 10MHz.
b. Set the 654A controls as follows:
FREQUENCY RANGE X1K
FREQUENCY dial 10
OUTPUT LEVEL dBm + 10,0
IMPEDANCE
AMPLITUDE
50 UNBAL
Adjust for
OdBm on 654A meter
c. On the rear panels of the instruments, connect the
312A Wave Analyzer RECORDER OUTPUT to
the 313A Tracking Oscillator RECORDER
INPUT. Set the tracking oscillator METER MODE
switch to EXPAND 312A.
d. Set the external attenuator to - 1dB position.
e. Adjust the wave analyzer to the same frequency as
the 654A and for a meter indication of between
-7dB and + 3dB.
f. Adjust the tracking oscillator SCALE OFFSET
control for a OdB reference indication on the
oscillator meter.
g. Set the external attenuator for OdB attenuation.
h. Adjust the 654A AMPLITUDE control to return
the tracking oscillator meter indication to OdB
reference; 654A meter should indicate - 1dBm,
+/-0.05dBm.
i. Set the external attenuator to - 2dB position.
j. Adjust the 654A AMPLITUDE control to return
the tracking oscillator meter indication to OdB
reference; 654A meter should indicate + 1dBm,
+/-0.05dBm.
TEST OSCILLATOR
hp654A
654,6-18911
TRACKING OSCILLATOR
hp3I3A
WAVE ANALYZER
hp3I2A
IDB/STEP
ATTENUATOR
hp 355C
Di DI ED
ci
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Figure 5-5. Meter Tracking Accuracy Check
5-6