16. YIG-Tuned Filter/Mixer (RYTHM) Adjustment
Procedure
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Set the HP 85623 luNE) switch to off and disconnect the line cord. Remove the spectrum
analyzer cover, fold down the Al4 and Al5 board assemblies, and connect the line cord.
Connect the equipment as illustrated in Figure 2-25. Press (LINE) to turn the spectrum
analyzer on.
Move the WR PROT/WR
ENA
jumper on the A2 controller assembly to the WR ENA
position. The jumper is on the edge of the A2 board assembly and can be moved without
folding the board down.
Press
(PRESET)
on the HP 85623 and set the controls as follows:
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 GHz
Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OHz
On the HP 85623, press
ICAL),
IF AD3 ON OFF so OFF is underlined, MORE
1
OF 2,
SERVICE CAL DATA,
PEESEL
ADJ,then PRESET ALL DACS.
Press (INSTR PRESET) on the HP 8340A and set the controls as follows:
CW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 GHz
Power level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -10
dBm
Frequency standard switch (rear panel) . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . EXT
Press PRESEL OFFSET on the HP 85623. Use the front-panel knob to peak the displayed
trace. Record the offset DAC value below:
Offset at 4.0
GHz
=
Set the HP 85623 center frequency and the HP 8340A
a
to 12.16 GHz.
On the HP 85623, press
ICAL),
MORE
1
OF 2,
SERVICE
GAL DATA, PRESEL ADJ , then
PRESEL OFFSET. Key in the offset value noted in step 6.
Press PRESEL SLOPE on the HP 8562E. Use the front-panel knob to peak the displayed
trace. Record the slope DAC value below:
Slope at 12.16
GHz
=
Set the HP 85623 center frequency and the HP 8340A
a
to 4.0 GHz.
On the HP 85623, press (CAL), MORE
1
OF 2, SERVICE CAL DATA, PRESEL ADJ , then
PREZZL
SLOPE. Key in the slope value noted in step 9.
Repeat steps 6 through 11 until both SLOPE and OFFSET are peaked. Adjust the
OFFSET only at 4.0 GHz and the SLOPE only at 12.16 GHz.
Press
PBESEL
OFFSET . Press
a
to display OFFSET FOR BAND
#2.
Key in the offset value
recorded in step 6.
Adjustment Procedures 2-61