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TX26: C58, the last .1 uf capacitor.
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TX27: C59, .001 uf.
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TX28: L13, 1.5 turn hand-wound coil. Review "TC" and TX16.
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TX29 C73, 18 pf.
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TX30: C55, .01 uf.
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TX31: C74, 35 pf trimmer.
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TX32: C84, 35 pf trimmer.
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TX33: C64, .001 uf.
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TX34: L8, 2.2 uH molded inductor (2 red, 1 gold and 1 black stripe).
At this point, every single main PC board component has been installed
except for L10, R32 and L9, which apply power to the RF output transistors
(driver Q9, final Q8). DO NOT INSTALL these parts until instructed to do so
during the Transmitter Completion and Tuneup procedure.
Stage TX: FINAL PROGRESS CHECK:
1.
Double check component selection for Steps TX.
2.
Use bright light and magnifier to go over entire board to check for
missed connections or solder bridges. If you suspect a solder bridge,
simple review the X-ray illustrations to see whether the points in
question are indeed tied together.
3.
Carefully check entire board for:
A. Loose bits of wire lodged among connections or components on
either side of board.
B. Excess wire lengths which may not have been nipped and are now
bent flat, probably against another connection.
BUILDING THE LOW PASS FILTER PC BOARD:
The assembly of the low pass filter PC board is quite different from the way in
which you have assembled the main FX transceiver board. Component parts
are mounted on the circuit trace/solder side of the board! The reason for this is
that the board mounts against the output connector - and it would be very
difficult to solder the connector center pin after the board is mounted to it.
You'll see why as you finish building your rig.
When installing parts, insert the component on to the PC board from the
solder side, the leads will extend out through the bare side of the board with
no traces. The part is then soldered on the solder side and the leads trimmed
away flush on the other side. When soldering the disc caps, be sure that their
leads are properly soldered, sometimes the body insulating material will coat
FX-146
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resoldered after passing through the grommet. Snap in the locking
section of the relief grommet only AFTER both the red and black wires
are in place.
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4. Remove the two screws from the SO-239 antenna connector, gently
bend the lugs as needed to match the rear panel holes, then secure the
jack and lugs to the rear panel.
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5. Since the top shell will not be needed until you're ready to go on the
air, keep it wrapped in protective material until you're really ready to use
it.
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6. The side rails may be installed to the bottom section at any time. To
prevent loss of the screws for the top, keep them loosely threaded in the
side rails.
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7. There is no point in securing the front panel controls and jacks to the
panel permanently until AFTER wiring the Channel Selection switch.
Note the locking hole for the switch in the front panel which mates the
tab on the front of the switch.
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8. Use care and a well chosen pair of pliers to secure the microphone
and speaker jacks to the front panel, so as not to scratch the panel.
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9. Bend the leads of the TX LED so that their tension presses the front
of the bulb against its front panel hole.
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10. Whenever you find it necessary to remove the top shell, "store" the
screws back into their holes in the side rails.
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11. If you decide to install a ribbon cable in the diode matrix for external
programming control, route the cable (folded at a right angle) on the
synthesizer and receiver side of the board so that it exits the case
between the rear panel and top cover, right above the DC power cord.
Do NOT route any such cable across the VCO and transmitter side.
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12. After the PC board is secured to the case bottom and front/rear
panels, it is a good idea to neaten up the wires to the controls and
jacks, bundling them at two or three points with tie wraps or cord.