Wavetek 3000 Instruction Manual page 192

GENERAL INFORMATION
This factory-installed option requires
the addition of a Programmable
Attenuator
and M42 Attenuator Drive
module to the standard signal generator,
and provides
remote programming of the
RF
level via
the rear-panel input
connector using
8-4-2-1 BCD contact
closures or TTL signals . The level
_programming range covers 0 to 90 dB in 10
dB steps . The O dB reference point is
set to the desired level by
the
instrument front-panel attenuators .
Remote selection of CW or AM mode is
also provided by a switch-contact
closure or a TTL signal .
Reverse-power
protection is also
provided by
this option to prevent
damage
to the instrument if DC (100 V
max)
or RF
(50
W max) voltages are
inadvertently applied to the instrument
RF OUT connector .
NOTE
DC protection is not included on
Model 3002 .
Due to
the slight "insertion loss" and
change
'in flatness caused by
addition
of the
Programmable Attenuator
to the
instrument, it will not be
possible to
obtain +13
dBm . output at
all
frequencies, therefore,
the
maximum
calibrated output
is +12 dBm
when
Option 1B is installed .
OPERATING INSTRUCTIONS
Front-Panel Operation
REMOTE PROGRAMMING
OPTION 1B
RF LEVEL PROGRAMMING
Table 8/1B-1
lists . instrument
specifications which
are additions to
or deviations from
the specifications
given in Section 1 of
the instrument
instruction manual .
Refer to Figure 8/1B-2
for location of
added components .
Front-panel operation remains basically
the same as for
a standard instrument,
except that the
maximum calibrated
output is +12 dBm .
However, any
external
RF level programming must be
removed or the front-panel
indicated
output level will be incorrect .
Also,
the external CW/AM programming must be
set to AM in order for
the front-panel
MODE switch to function properly .
Six wires are required to
connect the
remote
programming switches
or TTL
signals to the rear-panel PROGRAMMING
plug (see Figure 8/1B-1) : four
are
used for
level programming, one
for
mode selection (CW or AM), and
one is
common
(ground) . 8-4-2-1
BCD switch
closures
or TTL
signals are used to
select
the attenuator 10 dB steps over
a range of 0 to 90 dB as shown in Table
8/1B-2 .
After the programming switches have been
connected to the rear-panel PROGRAMMING
plug, the 0 dB
reference point is set
to the desired value by the front-panel
attenuators ; then, the 10 dB steps are