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1) Solder in the socket for IC1.
To avoid confusion or mistakes later, align the
dimple at one end of the socket, with the
dimple illustrated on the PCB. The dimple
should be at the end nearest the right-hand
edge of the PCB.
2) Solder in all capacitors and the quartz
crystal (note there is no C7).
Be careful not to mix up the 22pF and 10nF
capacitors. The two 22pF capacitors are the
ones on each side of the crystal.
3) Fit and solder switches S1 and S2
The switches are in a convenient location to
press with your left and right index fingers
when holding the module in your hands, with
the LCD facing you. However, it is certainly
nicer to fit off-board switches as well, on a
front panel (see later "hardware options"
section).
4) Wind and install the toroid
The silkscreen printing on the PCB shows
vertical mounting of the toroid. If you prefer
horizontal mounting, there is enough space for
it. When winding the toroid, remember that
each time the wire goes through the centre of
the toroid counts as one turn. 35cm of wire
should be enough for 25 turns. Trim the ends
of the wire, scrape the enamel off and tin them
with solder. As an alternative to scraping the
enamel off, the wire ends may be held in a hot blob of solder on the iron tip for a few seconds, and
the enamel will bubble away. Check continuity on the board with a DVM.
5) Solder the sockets for the Si5351A
synthesiser module and the low-pass-filter
board.
Some care needs to be taken with the
alignment, to ensure that there is a good fit
when the plug-in boards are added. One
method is to build the plug-in modules first;
then use the Si5351A and LPF boards
plugged into the sockets. You can then solder
the pins, ensuring correct alignment.
5
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