Front Panel Features - HP 436A Operating And Service Manual

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Model 436A
FRONT PANEL FEATURES
0
Digital Readout:
Indicates sign and decimal value of
RF input power in Watts, dBm, or in dB relative to a
stored reference.
0
Range Lamps (W,mW, µW, nW):
Enabled in WATT
MODE. Light to indicate level of Digital Readout
indication.
0
dBm:
Lights to indicate that dBm MODE is selected
and Digital Readout indication is in dBm.
0
dB (REL):
Lights to indicate that dB RELATIVE
MODE is selected and Digital Readout indication is in
dB with respect to stored reference level.
9
ZERO:
Lights to indicate that power sensor auto-zero
circuit is enabled and
9
RF BLANKING output is
active.
0
REMOTE:
Associated with the Hewlett-Packard
Interface Bus Option 022. Lights to indicate that
front-panel switches are disabled and power meter
operation is being controlled via remote interface.
8
POWER REF ON:
Alternate action .fushbutton
switch. When set to ON (in), enables
U
POWER
REF OUTPUT.
0
POWER REF OUTPUT:
Enabled when
8
POWER
REF switch is set to ON. Provides RF output of 1.00
mW± 0.70% for system calibration.
0
LINE ON-OFF:
Alternate action pushbutton switch.
Applies ac line power to Power Meter when set to ON
(in).
Ci)
SENSOR ZERO:
Spring-loaded pushbutton switch.
When pressed, enables Power Sensor auto zero loop
for a period of approximately 4 seconds (
0
ZERO
lamp remains lit for the duration of this period).
NOTE
In order to auto-zero the Power Sensor,
no RF inp_ut power may be applied
while the
0
ZERO lamp is lit. If any
RF input power is applied, it will
introduce an offset that will affect all
subsequent measurements.
Operation
G
RANGE HOLD:
Alternate action pushbutton switch.
When set to off (out) allows Power Meter to auto-
range as required to track changes in RF input power
level. When set to on (in), locks Power Meter in last
range enabled during autoranging.
G
CAL FACTOR %:
Rotary switch which changes the
gain of the Power Meter amplifier circuits to com-
pensate for mismatch losses and effective efficiency
of the Power Sensor. A chart of CAL FACTOR
%
versus frequency is printed on each Power Sensor.
CD
CAL ADJ:
Screwdriver adjustment for calibrating the
Power Meter and any Power Sensor to a known
standard.
4D
SENSOR:
Provides input connection for Power
Sensor via Power Sensor Cable.
Gl
MODE:
Interlocking pushbutton switches which
configure the Power Meter to indicate average RF
input power in watts, in dBm, or in dB with respect
to a stored reference .
WATT:
Alternate action pushbutton switch.
When set to on (in), selects WA TT Mode. (Power
Meter is configured to indicate RF input power
in watts, milliwatts, microwatts, or nanowatts.
dBm:
Alternate action pushbutton switch. When
set to on (in), selects dBm Mode. (Power Meter
is configured to indicate RF input power in
dBm.)
dB [REF]:
Spring-loaded pushbutton switch.
When pressed, selects dB Relative Mode. (RF
input power level displayed on
0
Digital
Readout is stored as dB reference and
Q,
Digital Readout changes to 0. Then Power Meter
is configured
to
indicate changes in RF input
level in dB with respect
to
stored reference.)
NOTE
When the dB relative mode is selected, the
WATT Mode or dBm Mode can be
selected by pressing the
Gl
WATT MODE
or dBm Mode switch and the power applied
to the Sensor is displayed on the
0
Digital
(continued)
Figure 3-1. Front and Rear Panel Controls, Connectors, and Indicators (2 of 4)
3-3