Wavetek 3000 Instruction Manual page 47

4 .5 .1 Output Meter Accuracy Test
EQUIPMENT
Power Meter
and Sensor
PROCEDURE
Note that no step attenuator pads are active in the +10 dBm
and 0 dBm positions . A leveled pin-diode attenuator reduces
the output level by 10 dB in all positions of the output
step attenuator below +10 dBm . The output level over the
entire range of +13 dBm to -137 dBm including a 10 dB vernier
is controlled by the pin leveler system .
The output step attenuator error is measured by an RF sub-
stitution method . Each of the five pads in the output step
attenuator is measured at 520 MHz . The second 30 dB pad
and the 40 dB pad are measured in combination with other
pads . A reference output level is set with a power meter .
A reference trace is obtained with a spectrum analyzer and a
standard attenuator pad . The standard pad is removed and
the output step attenuator position to be measured is sub-
stituted . The spectrum analyzer trace is returned to the
reference level by resetting the Signal Generator output
level . The resulting Signal Generator output level is
measured and compared to the original power meter reference
level . A 26 dB RF amplifier is required to boost signal
levels below the -60 dBm level .
HP435A/8481A
1 . Set the Signal Generator controls
FREQUENCY selector
MODULATION MODE
MODULATION FREQ
MODULATION FM/AM
OUTPUT VERNIER
OUTPUT step attenuator
power
cates
NOTE :
PERFORMANCE TESTS
as follows :
050 .000 MHz
CW
(Inactive in CW MODE)
(Inactive in CW MODE)
Fully Clockwise
+10 dBm
Set the
sensor
2 .
Calibrate the power meter
and power sensor .
power meter to the +15 dBm range . Connect the power
to the Signal Generator RF out connector .
(When reading the
meter, set the range switch
so that the meter indi-
between 0 and -5 dBm) .
The Signal Generator indicated output level is equal
to the sum of the OUTPUT meter reading and the step attenuator
setting . The difference between the actual power meter
reading and the indicated output level is the OUTPUT meter
error . For example, the indicated output level is +13 dBm
for an OUTPUT meter reading of +3 dBm and an OUTPUT step
attenuator setting of +10 dBm . If the power meter reading
is +13 .15 dBm, the OUTPUT meter error is +0 .15 dB .
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