HP 8560E - Page 511

510 Chapter10
Synthesizer Section
Synthesizer Troubleshooting Section
9. Connect the CAL OUTPUT to INPUT 50 Ω.
10.Set the HP 8560E/EC to the following settings:
Center frequency..................................................... 300 MHz
Span ......................................................................... 100MHz
Trigger ..........................................................................CONT
11.If the first LO is present, a signal should be displayed at about −10
dBm (approximately ±20 MHz from the center frequency). If no
signal is displayed and ERR 334 LO AMPL is not present, suspect
the A7 LODA. If no signal is displayed and ERR 334 LO AMPL is
present, check the A11 YTO as follows:
a. Set jumper A14J23 to the TEST position.
b. Set the HP 8560E/EC to the following settings:
Center frequency ...................................................... 50Hz
CF step ................................................................ 300MHz
Span .............................................................................0Hz
c. Connect a power meter directly to the output of the A11 YTO.
d. Press the HP 8560E/EC step-up key and measure the YTO output
power at each step.
e. Verify that the output power of the A11 YTO is between +9 and
+13 dBm.
f. Set jumper A14J23 to the NORM position and reconnect the A11
YTO.
Check A14 frequency control assembly (steps 12-17)
12.On the HP 8560E/EC, press
PRESET, SPAN, ZERO SPAN, CAL, MORE
1 OF 2, FREQ DIAGNOSE, and FRAC N FREQ. Note the fractional N
oscillator frequency. (Ignore the minus sign, if present.)
13.Check A14J304 (FRAC N TEST) port with a spectrum analyzer for
this exact frequency. The amplitude should be approximately −10
dBm.
14.Disconnect W32 from A14J501 and connect the output of a signal
source to A14J501. Remove the jumper from A14J23. Connect the
positive lead of a DVM to A14J23 pin 1, and the negative lead to
A14J23 pin 3. See Figure 10-1 on page 511.
15.Set the signal source to the following settings:
Power ........................................................................... 0dBm
Frequency ............................. Frequency recorded in step 12
Fractional N Oscillator Frequency = __________________MHz