HP 8340B Manual page 240

5-6.
YO PRETUNE DAC, A54
Reference
Performance Test: None
Service Section: Sweep Generator
—
YO
Loop
Description
This procedure makes
gain and offset adjustments
to
the pretune voltage such that
the lowest output
voltage from the DAC
will
tune the YO to its lowest frequency (2.3 GHz), and the highest voltage out of
the DAC (full scale)
will
tune the YO to
its
highest frequency (7 GHz).
DIGITAL VOLTMETER
INPUT
Figure 5-13.
YO
Pretune
DAC
Gain
Test Setup
Equipment
Digital
Voltmeter (DVM)
Procedure
HP 3456A
1.
Position the
DUT
in the test position as shown
in
Figure 5-13 with bottom cover removed and
turn
the LINE switch
on. Connect
the test equipment as shown
in Figure 5-13 and allow one-half hour
warm
up time. Be sure to
connect
DVM
ground to
A54TP7 RGND.
2.
Set the
DUT
as follows:
a.
Press
[INSTR PRESET]
b.
Press
[CW]
then enter
[2]
[.]
[3] [GHz]
to tune the
YO
to
2.3 GHz (minimum DAC output).
3.
Connect the DVM to A54TP6 (VDAC)
and adjust
A54R22
(POFF, Figure 5-14) for
-5.75 ±0.001
Vdc.
4. Press
[CW]
on
the
DUT, then
enter [6] [9] [9] [9] [.] [9] [9] [9] [9] [9]
[MHz]
to set the
YO
close to
7
GHz
(maximum
DAC
output).
5.
Adjust A54R14 (PGN,
Figure 5-14)
for
-17.5
±0.001
Vdc.
HP 8340B/41B
Adjustments