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- Capacitors. Leakage can be traced with an ohmmeter adjusted to the highest resistance range.
When testing take care of polarity and maximum allowed voltage. An open capacitor can be checked if the
response for AC signals is observed. Also a capacitance meter can be used: compare the measured value with
value and tolerance indicated in the parts list.
- Resistors. Can be checked with an ohmmeter after having unsoldered one side of the resistor from the p.c.b.
Compare the measured value with value and tolerance indicated in the parts list.
- Coils and transformers. An ohmmeter can be used for tracing an open circuit. Shorted or partially shorted
windings can be found by checking the wave-form response when H F signals are passed through the circuit.
Also an inductance meter can be used.
NOTE:
I f a component must be replaced always use a direct-replacement. I f not available use an equivalent
after carefully checking that
6.2.
(replacement).
After replacement o f a component the calibration o f the instrument may be affected due to
component tolerances. I f necessary d o the required adjustments.
Checks after repair and maintenance.
6.5.3.
Checking the protective lead in instruments with a three-wire mains cable
The correct connection and condition is checked by visual control and by measuring the resistance between
the protective-lead connection
The resistance should be
variations indicate
a
6.5.3.2. Checking the insulating resistance.
Measure the insulating resistance a t Udc
connections. For this purpose set the mains switch t o ON. The insulating resistance should be
6.6.
OPTIONAL MTB GATE OUTPUT, DTB GATE OUTPUT, MTB SWEEP OUTPUT AND TTL OR ECL
TRIGGERING
6.6.1.
MTB and DTB gate
For these options
it
these sockets and respectively socket X209 (MTB gate) and socket X211 (DTB gate) on the time base unit.
For ordering numbers of BNC sockets and coaxial cables
MTB
install R270 (33E2,5322 116 50527).
gate:
DTB
gate:
close soldering bridge between 0208 and R273.
6.6.2.
MTB
sweep
out
For this option it is necessary to install
lay-out (see
8.8).
fig.
R352
1 KIM R25
R353
1 K271M R25
R354
V267
C252
15U F/40 V
C266
X218
Coax socket, outer part
Coax socket, contact pin
Mount
BNC socket on the rear panel and add
a
the time base unit. For ordering numbers of BNC socket and coaxial cable refer to the parts l i s t in chapter 7.
it
does not degrade the instrument's performance. See also section
a t
the plug and the cabinet.
<
0,5
During measurement the mains cable should be moved. Resistance
defect.
500V between the mains connections and the protective lead
=
is only necessary to install BNC sockets a t the rear panel and to add coaxial cables between
number of components in tne way indicated on the time base p.c.b.
a
5322 116 54549
5322 116 50555
5322 116 54192
482213044196
482212420709
4822 121 41 134
532226824116
532226814141
coaxial cable between the BNC socket and socket X218 on
a
see
the parts l i s t in chapter 7.
6-13
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