HP 8562E, Service Manual

Page: 413 / 482

Set the spectrum analyzer to the following settings:
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
z
Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SINGLE,EXT
a.
b.
C.
d.
e.
f.
h.
i.
k.
On the spectrum analyzer, press (SAVE), , .
Remove jumper and connect a dc voltage source to pin 2. Connect the
voltage source ground to pin 3.
Connect a microwave frequency-counter or another spectrum analyzer to the spectrum
analyzer first LO OUTPUT (front panel output).
Set the dc-voltage source output for 0 Vdc and note the 1st LO frequency.
Set the dc-voltage source output for
Vdc. The first LO frequency should
momentarily increase approximately MHz.
The voltage at pin 2 should be approximately 19% of the voltage at
pin 2.
If the first LO frequency did not change in step e, press
to turn spectrum analyzer
off and disconnect from
Place a jumper between pins 9 and 10. Place a 50 3 watt resistor across
pins 5 and 6 (resistor, HP part number 0811-1086). Press to turn spectrum
analyzer on.
On the spectrum analyzer, press
, STATE 0 .
If the voltage at U332 pin 2 is correct with pins 9 and 10 shorted, but was
incorrect with connected, the YTO FM coil is probably open; replace the
All YTO.
Replace jumper
If the fractional N spans are inaccurate or non-existent, but the fractional N PLL is locked to
the correct frequency and other spans are correct, there may be a problem with the HSCAN
signal. Check that HSCAN is present at the fractional divider, U113 pin 41 in function block
AS. HSCAN comes from the A3 interface assembly and goes to the sweep generator circuitry
in function block A and to fractional N.
Synthesizer Section 1 l-39