Wavetek 3000 - Operating Procedure; AM Modulation Procedures

signal displayed
on the oscilloscope
.
The instrument is
now ready foruse .
2.7
OPERATINGPROCEDURE
No preparation for
operation is required
beyond completion
of the initial
in-
stallation checks
contained in Section
2 .6 . To insure
that the Model 3000 will
perform as stated
in the specifications,
the
instrument should have a
two hour
warmup
before using .
2.7.1
TurnOn
Verify
that the power transformer
pri-
mary
is matched to the line
voltage
available and that the proper
fuse is
installed (See Section 2 .3
Electrical
Installation .

Turn the front

panel
switch "ON" .

One or

more
front

panel
accuracy lights will be
illuminated
indicating an operating
condition .
NOTE :

A flashing
indication on the
lights indicates
an unlocked condition .
This should cease
in a matter of sec-
onds .

If
the flashing does not
cease,
refer to
thewarranty on the back
of the
title page .

If
the unit is not
going
to be used to
the extreme limits of
its
specifications, it can be
usedimmedi-
ately,
otherwise a two hour warmup
is
required
.
NOTE :

Whenworking
withactive circuits,
transceivers, etc ., care should
be used
to keep voltage or RF power from
being
applied to the RF
output

connector .
Damage may occur to
the output attenuator
circuitry of the
Model 3000 if this hap-
pens .
2 .7 .2 Frequency
Selection
Select
the frequencydesired
with the
six Lever
Indicator switches
on the
front panel . A frequency
between 1 and
520 MHz can be selected
with a 1 kHz
resolution .
2,7 .3
OutputLevel Selection
Set the output attenuator and
vernier
to the
desired level . The output
is
continuously adjustable over a +13
to
-137 dBm
range .

The level shown
on the
attenuator
added to the meter
indication
equals
the RF output .

NOTE : AM
modu-
lation
is possible at levels
above +3
dBm
as long as the peak of
the modulated
output does not
exceed the +13 dBmmax-
imum output
level .

If this level is ex-
ceeded the
unlevel light will illuminate
indicating
an unleveledcondition .
2.7.4 AM
Modulation - Internal
OPFRATION
Set the mode
switch to AM and the fre-
quency
switch to either 400 or 1000
Hz
modulation
rate . Adjust the AM/FMver-
nier to
indicate the desired modulation
depth .
2
.7 .5 AM Modulation - External
CAUTION : Input
voltages greater than
±10
VDC
or 10 VRMS
should not be applied
to the external
modulation input con-
nector or damagemay
occur to internal
circuitry of the Model
3000 .
Set the mode
switch to AM and the fre-
quencyswitch
to external . Apply a 10
V p-p signal into
600 ohms to the Exter
nal
modulation input connector .

This
calibrates the'AM/FM Vernier
control .
The desired
modulation depth can
then be
set .

The upper frequency limit of
this
input is 20 kHz .
NOTE :

When AM modulating, care
must be
taken not to exceed
the +13 dBm maximum
level or excessive
distortion and an
unlevelcondition
can exist .

In some
cases, a high
% of AM modulationmay
cause the unlevel
light to come on when
the RF
vernier control is at minimum .
This
is caused by the bottoming of the
PINdiode
leveler

which in turn
can
causean
increase in distortion .

If
2-7