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position. If a lower sideband filter is installed, the companion
upper sideband fllter must also be installed in one of the re-
maining fllter positions. If a symmetrical sideband fllter is used,
the Receiver will use the fIlter installed in the FLI position
for both sidebands by making the appropriate frequency offsets
to the fIrst and second local oscillators.
The remaining ftlters may be installed in any sequence in fllter positions FL2 through FL 7.
However, in order to simplify system operation and troubleshooting, it
is
recommeI1ded that a format
be established and used for all Receivers at a particular site.
A
typical format would be to' in,sert the
USB filter (if used) in position FL2 and ins.ert fIlters with increasing bandwidths in filter positions .
3 through 7.
Once the fIlter complement and arrangement has been determined, the following procedure
should be used to insert the fIlters into the Receiver:
.
1. Working from the front of the Receiver, position the fIlter to be used for LSB operation
over fIlter position FLI (the fIlter position closest to the rear of the Receiver). Make
certain that the large pins are aligned with the large sockets and the smaller pins are
aligned with the smaller sockets.
2. Carefully push down on the filter to insert the pins into the sockets. Relatively light
pressure is required to insert the pins into the sockets. If the fIlter does not easily
slide into place, recheck the pin/socket alignments.
3. Insert the appropriate filters into fIlter positions FL2 through FL7 (as required), using
the procedures described in steps I and 2.
4. After all fllters have been inserted, visually inspect the ftlters to insure that they are
properly seated. The bottom of the ftlters should be flat against the surface of the A4
board.
5. Replace the RF shield over the fIlters and secure the shield in place by tightening the
three screws. .
5.8
OPERATIONAL FAULT SYMPTOM CHART
Table 5-6 contains· typical operational fault symptoms and their most probable causes. The
table should be used as a guideline only, and should be supplemented with the BITE check detailed in
Paragraph 5.4.2 and the Performance Tests detailed in Paragraph 5.5.
5-31
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