Yaesu FT-900 Operating Manual page 40

Installing Internal Accessories
This chapter describes Installation of the ln1ernal
optiOns available for the FT-900. The ATU-2 automatic
antenna tuner and the XF·1 10C or XF-1 10CN and
XF·110S crystal filters are installed by removing only
the bollom cover, while installing the TCX0-3 master
oscillator requires removing first the bottom cover and
then tho top cover/heatsink. This chapter describes
the cover removal procedures first. followed by the
indJvrduaJ procedures for oach option. Proper porlornn·
ance with these optiOns depends oo proper installa·
tiOn.
II
you are unsure of the procedures afler readrng
the following , please ask
your
Yaesu deafer for help.
Cover Removal
0
Turn the transcerver orr. and disconnect all cables.
0
Place the set upside-down on the work surface wrth
the rear facing
you.
and remove the eight screws
affixing the bottom cover (Figure 1). Then hit the
bottom cover off.
If you are Installing only lhe ATU·2, proceed directly
from here to the procedure on page 40.
::J
Disconnect the fight·blue-banded coaxral cable
l!!?.m J2026 near the rear olthe exposed AF Unit
(W In Figure 2). II you are not installing
any
crystal
ftltors. skip the next three steps.
0 II installing crystal fillers
you
will need to aoccss the
solder side of the RF Unit. Unplug the yellow·
b;mdcd coaxial cable from J2024 ncar the rear
corner of the RF Unit
< ®
in Figure 2).
0
Using a small sharp toot, gently pry up on either
side ol J20 1 1, the white plastic ribbon cable socket
near the rear left corner of the RF Unit
(Q)
in Figure
2), about 2 mm ('A! inch), until the ribbon cable can
be removed (see Figure 3).
0
Remove the six screws Indicated in Figure 2 (one
is inside the large shield housing, accessible
through the hole near the corner).
:J
If not rnstalflng the TCX0-3, the crystal filters can
now be installed as described on page 40. Other-
wise, continue with the following steps;
TCX0-3 Enhanced-Stability
Crystal Oscillator Option
The i2·ppm TXC0-3 option can be installed es a
replacement for the standard ±10-ppm crystal oscilla·
tor.
0
Place the transceiver topside-up, and remove the
four screws indicated in Figure 4.
:J
Now turn the transceiver onto its right sfdo (as
viewed from the rear). Lift the rear of the top
coveriheasink about 2 em
(:j/ 4
inch), then shde
it
back slightly and begin to fold away the uppermost
side. Using care to unhook the coaxial cable that
was disconnected abovo from the RF Unit, fold the
two halves of the chassis apan until they lay flat,
side by side.
Figure
1:
Bottom Cover Removal
Figure 2: RF Unit Location
Figure 3: Ribbon Cable Connector
page37