4. Output Monitor Accuracy Test; Attenuator Test - HP 652A Operating And Service Manual

Table 5�4. Flatness Test Settings and L i m its*.
*(Amplitude readjusted to a reference
on the output monitor)
FREQUENCY FREQUENCY
DIAL DIAL
( 1 0 Hz to 20 Hz)
1
X I O
X l O 1 .2
1 5
XlO
2
XIO
(20 Hz to 4 MHz)
XlO 2
X 100 1
XlOO 5
XIK 1
XIK 5
XIOK 1
XIOK 5
X lOOK 1
X lOOK 5
XIM 1
4
XIM
(4 MHz to 1 0 MHz)
4
XIM
XIM 6
XIM 8
10
X I M
monitor. (Do not readjust reference supply.) Record de null
meter indication.
g. Repeat Step f of this paragraph at each of the 652A
FREQUENCY RANGE and FREQUENCY dial settings
given in Table 5·4.
h. To determine that the readings recorded in Steps f
and g are within tolerance, two conditions must be met:
I) Each reading must be within 0.5% of the
reference level established in Step c.
TEST OSCILLATOR
hp 652A
©
fi S ? A
Monel
TOLERANCE
2%
2%
2%
2%
1 %
1 %
1 %
1 %
1 %
1 %
1 %
1 %
1 %
1 %
1 %
2%
2%
2%
2%
AMPLI FI ER
hp 461A
©
500 COAXIAL
1
�� ;
I O d S / S T E P
A T T E N U A T O R
h p 3 5 5 0
Figure 5A. Attenuator Test.
2) The difference between the highest and lowest
readings must be no greater than 0.5% of the
reference level established in Step c. These two
conditions verify 652A output flatness, referenced to
the expanded monitor, of ± 0.25% over the fre­
quency range of 10 Hz lo 1 0 MHz.
i. If flatness specifications are not met, first assure that
tolerances of Paragraphs 5-1 1 and 5- 1 2 are met, then
perform calibration procedure of Paragraphs 5-37 and 5-38.
5·14. Output Monitor Accuracy Test
a. Connect ac voltmeter to 50 ohm output terminal of
652A as shown in Figure 5-2. Use an ac voltmeter with
known accuracy at frequency to be used (400 Hz).
b. Set 652A controls as follows :
FREQUENCY RANGE . . . . . . . . . . . . . X I OO
FREQUENCY dial . . . . . . . . . . . . . . . . . . . , 4
OUTPUT ATTENUATOR . . . . . . . . . . 3.0 V
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
c. Set OUTPUT AMPLITUDE and VERNIER controls
for a 3.0 V indication on 652A monitor. AC voltmeter
should indicate 3 V ± 0.06 V (± 2%)rms, verifying an
output monitor accuracy of ± 2% of full scale.
d. If tolerance is not met, perform Normal Monitor
Calibration, Paragraph 540.
5·1 5.

Attenuator Test

a. Connect external attenuator, amplifier, ac voltmeter
and digital voltmeter to 652A as shown in Figure 5·4. Use
an attcnuator with known accuracy.
Float amplifier, ac voltmeter and digital voltmeter
using an adequate isolation transformer to isolate
chassis ground from power line ground.
R M S
VOLTMETER
hp 3400A
: I�D :'; C � O � U:::' T
�
©
50 OHM
FEED THRU
hpl1048C
NOTE
DISPLAY
34740A
hp
MUL TIMETER
MYLAR
34702A
hp
Section V
5·5