15. M/N Loop Adjustments
L O C K I N D I C A T O R
O U T P U T
D I S A B L E
F R E O A D J
T U N E
POWER
Figure 3-68. Location of PLL Adjustments
4. Disconnect the cable 93 (white/orange) from
M/N OUT in
the RF Section. Refer to Figure 3-68 for the location of the
M/N Output Assembly.
5. Connect the frequency counter BNC input to
M/N OUT
using a BNC to SMB Snap-on Test Cable. Set the input selector
switch on the frequency counter to
HZ
500
MHZ
,
and set the
impedance switch to
6. Set the RF Section LINE switch to ON and press
Key in
(SHIFT)
[
CENTER FREQUENCY
)
6090.000 MHz,
(
FREQUENCY SPAN
)
0 Hz. The frequency counter indication should
be 197.419355 MHz
count.
7. Connect the DVM to
TUNE test point.
8. Adjust
FREQ ADJ tuning slug for a DVM indication
of -35.0
Vdc. Slightly loosen the hex locking nut before
adjusting the FREQ ADJ tuning slug, and tighten the nut after the
appropriate voltage is set.
9. Key in
(
CENTER FREQUENCY
)
2100.000 MHz on the RF Section.
The frequency counter indication should be 177.500000 MHz
count, and the DVM indication should be -2.3 f0.5 Vdc.
10. Set the RF Section LINE switch to STANDBY.
11. Disconnect the frequency counter and DVM from the
Output Assembly.
12. Disconnect the cable 92 (white/red) from
355-395 MHz
OUT on the
Output Assembly. Remove the
Output Assembly from the RF Section, and install it on an
extender board.
13. Press
on the second spectrum analyzer. Connect the CAL
OUTPUT signal to the RF INPUT on the second spectrum analyzer,
and press
8.
Adjustments 3-133
