Filter
Top Products
Check First LO (steps 9-11)
9. Connect the CAL OUTPUT to INPUT 50R.
10. Set the spectrum analyzer to the following settings:
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..300MHz
Span
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..lOOMHz
11. If the first LO is present, a signal should be displayed at about -10
dBm
(approximately
f20
MHz from the center frequency). If no signal is displayed and ERR 334 LO AMPL is
not present, suspect the A7 SLODA. If no signal is displayed and ERR 334 LO AMPL is
present, check the All YTO as follows:
;:
Set jumper A14J23 to the TEST position.
Set the spectrum analyzer to the following settings:
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz
CFstep
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..300MHz
Span
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz
1:
Connect a power meter directly to the output of the All YTO.
Press the spectrum analyzer step-up key and measure the YTO output power at each
step.
e.
Check that the All YTO output power is between
+9
and
+13
dBm.
f.
Set jumper A14J23 to the NORM position and reconnect the All YTO.
Check Al4 frequency control assembly (steps 12-18)
12.
On the spectrum analyzer press
c-1,
[m)),
ZERO
SPAhi,
(CAL), MORE
i
OF 2,
frREg
DTACNOSE , and
FRBC
hl
FRE$
. Note the fractional N oscillator frequency. (Ignore
the minus sign, if present.)
Fractional N Oscillator Frequency =
MHz
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 negative lead to A14J23 pin 3. See Figure 11-3.
15. Set the signal source to the following settings:
Power
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..OdBm
Frequency
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frequency recorded in step 12
16. Tune the source 1 kHz below the fractional N frequency. The voltage measured on the
DVM should be approximately 12 Vdc.
11-10 Synthesizer Section