Wavetek 3000 - Operation Check Procedure; Option 3 Maintenance

OPTION -3
OPERATION CHECK
KI
Figure
moving the externalRF signal from the
instrument .
Thenegative output from ICI also turns
off Q2, thus removing the short on pin
7 of timer IC2 . This allows the timer
to operate as an
astable oscillator .
The output, pin 3
of IC2, then varies
between 0 and 7 volts . This causes Q3,
the LED driver, to supply current inter-
mittently to the front-panel UNLEVELED
light, causing it to flash .
After the RF overload is removed, IC1
can be unlatchedby momentarily removing
AC power to the instrument .
The following procedure is recommended
to insure properoperation of the pro-
tection device . The top cover must
be removed from the instrument .
With the instrument operatingnormally
in theCW mode, set the outputlevel to
+5
dBm . Connect a
50
ohm detector to
the
output of the signal
generator . The
DC output of the detector should be
mon-
itored on a suitable oscilloscope . Set
the output frequency to
100
MHz .
The circuitry
in
the M35-1

is
checked
by
pushing the momentary switch located
on top of the module .

This switch
lowers the trip level of the
module .
While holdingdown
the switch slowly
increase the output of the unit
using
8/3-1 . Block Diagram
the VERNIERuntil the M35-1
trips .

This
causes the circuit
breaker to

open
and latch, the
UNLEVELED light to flash,
and the detected output
displayed on
the oscilloscope to go
to zero .

The
circuitbreaker can then be
reset by
momentarily turning the AC
POWER switch
off . The M35-1 should have tripped
at
+7
.5 dBm
_+1
dB .

Perform the
same test
at 500MHz .

It should then trip at an
output level of +10 .5 dBm +2 dB
.
The above procedure, while
not a complete
performance check, is
considered adequate
for mostapplications .
Additional tests
can be
performed as desired
. For example,
insertion
loss and VSWRcan be
checked
in the same
manner as any passive
device .
Also, if available,
a highpowerRF
sig-
nal source, set
for an output of slightly
over .7 W can be
used to verify
circuit
breaker operation .
MAINTENANCE
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
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The only maintenance
for the RF circuit
breaker is periodic
testing to
insure
its operation . If a
malfunction occurs,
a
trouble can be localized
and repaired
with
the aid of the theory
of operation
and the
schematic . If the
problem is a
defective
monitor diode, care
should be
observed to
keep lead length
and posi-
tion the
same as the original
diode .
Option 3
canbe factory or
field in-
stalled .
The
following procedure should
be
followed for field installation
.