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VERY IMPORTANT PC BOARD ASSEMBLY INFORMATION FOR A-L-L
OUR BUILDERS!
1.
Your FX- transceiver PC board is double-clad with plated- through holes.
What this means in practice is that it is VERY important to select and
install correct part values the FIRST time around. This type of board
makes "desoldering" much more difficult and risky because the solder
adheres inside the hole and fl ows to the component side of the board as
well. It is VERY tricky to remove a part without damaging it. If too much
de-soldering heat or component "pulling" is used, there is also the
serious risk of damaging small PC board traces. Be careful and
methodical in assembly!!!
2.
Do not, under any circumstances, install L9, R32 or L10 until instructed
to do so in Assembly Stage "TX." This applies even if you are following
your own assembly sequences. This procedure will prevent damage to
Q9 and Q8 during the initial test and alignment procedure.
3.
Do not attempt to "re-engineer" our transistor orientation illustrations.
Simply point flat sides or tabs as illustrated.
4.
After installing all parts, you will see a few empty holes in the circuit
traces on the top or component side of the board. These plated-through
holes are placed intentionally to connect with traces on the solder side.
The hole IS the connection! However, if these holes nag at you, simply
fill them in with a touch of solder -- AFTER verifying that all parts have
been placed and installed correctly.
5.
Additional "empty" holes are marked on the PC board to allow for easy
connection of accessories or modifications as you begin to customize
your transceiver. See "GUIDE TO FX- CIRCUIT ACCESS POINTS."
6.
The purpose of check boxes “p” in the assembly steps is to make it easy
to check the accuracy of your work at the end of each step.
7.
Almost all resistors are mounted in vertical (upright) position. You can
see that the wire leads for resistors come in several styles. If a resistor's
pre-trimmed lead is ever too short for upright installation, simply solder a
scrap wire nipped from another resistor to extend its length.
8.
Some of the resistors and miniature inductors used in this project require
upright or vertical installation. It is important to follow the orientation
illustrated for vertically installed parts. Always put the body of the part in
the hole with the circle!
9.
Whenever you have a choice, install parts with stamped markings so
that you can still see the markings later. This will help greatly with any
possible troubleshooting needed.
10. PARTS SORTING: In a kit of this size and complexity, there is no single
best way to sort and organize the 300+ individual components used. We
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Optional:
To a test speaker, temporarily or to a speaker intended for regular use inside
or along with your FX- Transceiver.
?
B16. Solder the speaker cable to your choice of speaker. Give attention
to the polarity marks on most bare speakers as well as enclosed units.
The wire from the point marked SPKR should be connected to the
speaker terminal marked (+).
Stage B: AUDIO AMPLIFIER TEST:
m
1. Reconnect 12 volts DC as done for testing the power input circuit in
stage A. (We assume speaker hookup per B15.)
m
2. Turn on power switch S1. All you should hear is one gentle "pop" in
the speaker. There should be no hiss or whistle. Touch the center
terminal of the volume control, and you should hear a moderate AC
hum. If you wish, connect a test oscillator or line-level audio source to
the input line to the control. You should hear a generous level of good
quality audio sound.
m
3. Disconnect DC Power before proceeding with assembly.
m
4. The volume control, speaker and other wired connections are installed
quite early in the assembly sequence so that tests can be performed
periodically during assembly. The disadvantage to this approach is that
there is considerable wear and strain on the various wire connections as
the PC board is repeatedly flipped back and forth during assembly. This
is a serious consideration because most radio malfunctions are due to
broken wires and not component failure. For this reason, such wiring is
usually done at the final stage of assembly. To minimize damage to the
controls and wiring, use a wire ty-rap, plastic bag tie or a scrap piece of
hook-up wire to hold down this group of wires temporarily. A convenient
point to loop your tie through is one of the PC board mounting holes
near U10.
