TEST OSCI LLATOR
hp652A
rr0
@
cUP TO
TO A2TP2
CHASSIS
50 OH
FEED T
M
HRU
8C
DISPLAY
hp 34740A
c==J
08�OOClCl :
hP I I04
MULTI METER
702A
hp 34
ELECTRONIC COUNTER
hp5245L
Figure
5M8.
Frequency Calibration.
NOTE
It is important to ensure that the XlK
RANGE calibration is completed before pro
ceeding to the other ranges as these are
referenced to the XlK RANGE.
5-10 gives a scaled drawing of top and bottom
alignment access covers with cut-outs that will
allow adjustments while the covers are in
place. The dimensions are given in inches.
c. The frequency calibration setup is shown in Figure
5·8. Output frequency should be continuously monitored
at the 50 ohm output with a counter. DC voltage at A2TP2
should also be monitored continuously, after Paragraph
5-28 has been performed.
e. The adjustments available for each range are listed in
Table 5-6. Some of these components listed change both
frequency and A2TP2 voltage in the same direction while
the others change them in opposite directions. If the
adjustments do not provide specified performance, then the
procedure for changing padding resistors of Table 5·6
should be carefully followed.
d. Table 5-7 lists frequency accuracy required at each
test frequency.
NOTE
5·10
NOTE
If any adjustments are necessary, the top and
bottom covers should be in place when final
frequency and A2TP2 voltage tests are made.
All internal shields must be in place and held
firmly by retaining screws. If desired, Figure
If 652A does not oscillate,
tum
FREQUENCY
RANGE switch to XlK and adjust A 2C5,
SIC2 and SlC7 to start oscillations.
5-28. Preliminary D istortion Adjustment
a. Connect 652A to distortion analyzer as shown in
Figure 5·5.
Table
5-6.
Frequency Calibration Components.
(Increasing the value of any of these components will decrease
the frequency and change the A2TP2 voltage as indicated.)
FREQUENCY
FREQUENCY
FREQUENCY
DIAL READING
=
1 0
DIAL READING
=
I
RANGE
Decreases
Increases
Increases
Decreases
A2TP2 Voltage
A2TP2 Voltage
A2TP2 Voltage
A2TP2 Voltage
XIO
SIC l S *
SIR! *
SIRI4*
XIOO
SIR3*
SIRI6*
XIK
SIC2
SIC7
SIR5*
SIRI8*
XIOK
SICI3*
SIR7*
SIR20 *
XIOOK
SIC4
SIC9
SIR9*
SIRn*
XIM
SICS
SICIO, SICI4*
SIRl I *
SIR24*
and A2C5
Section V
Model 652A