HP 75000 C Series Service Manual page 40

Set the Power Meter controls a s follows:
Calibration Factor
.....................
to power sensor 1 MHz value
Press dB
REF
......................................
to set a 0
dB reference
Calibration Factor
..................
to power sensor 500 MHz value
Set the Signal Generator frequency to 500 MHz, then adjust the
output level for a power meter reading a s close as possible to 0.0 dB
(REL).
Record the reading.
Power Meter
=
Set the HP E1426A controls as follows:
Time base to 5 nsec
....................................
T1M:RANG 5E-9
Digitize channel 1
................................................
DIGCHANl
..............................
Measure peak-to-peak voltage MEASVPP?
Record the measured peak-to-peak voltage.
V 500 MHz
=
Calculate the response from the measured results in steps
4
and 8
using the following formula:
VSOOMHZ
response(dB)
=
20 log1 0
=
20 b l 0
- -
dB
V1 MHz
Correct the result in step 9 with any difference in the power meter
reading from step 6 using the following formula. Observe signs.
( step 9 )
-
( step 6 )
=
dB
For example:
Result from step 9 = -2.3 dB
Power meter reading
=
-0.2 dB(REL)
then true response
-
(-2.3)-(-0.2)
=
-2.1 dB
Verify the result in step 10 is 13.0 dB.
Connect the power splitter to next channel being tested. Repeat
steps 2 through 12 for channels 2, 3, and
4.
Note
When repeating the procedure, all references to channel
1
should be
changed to the channel being tested. Turn off all unused channels
using the BLANk command.
Bandwidth ~ 8 0 mV
13. Connect the power splitter to channel 1 .
14.
Set the Signal Generator controls as follows:
Frequency
....................................................................
1 MHz
.....................................................................
Output -20.6 dBm
Note
Nov 15, 1990
Setting the output to -20.6 dBm will produce a -26.6 dBm level a t the
HP 1426A 5052 input (loss occurs through the power splitter).
Verification Tests 4-15