6 • BX-8x7
© Box 73 Amateurfunkservice GmbH 2014
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Construction
After checking all parts against the parts
list, you may begin assembly of the circu-
it board. You will need a temperature-con-
trolled low-voltage soldering iron, 1 mm
dia. rosin-cored solder, a pair of tweezers
and a small pair of wire-cutters.
Warning!
When working on the board, be
sure that it is not exposed to undue me-
chanical stress. Strong pressure, which
causes transverse deflection on the board,
should be avoided. Lengthwise rotation
(torsion) should be avoided as well.
Both RJ45 sockets are already inserted on
the board, so only the eight pins of each
socket need to be soldered to the board
Next, tantalum capacitor C3 is installed.
Its positive pole is marked with a dash,
and its correct positioning can be seen in
Figures 3 and 4 of the assembly guide.
When soldering C3, proceed as follows:
First, tin the solder pad of the terminal to
the board. Then, center the capacitor and
its solder connections over the board’s two
solder pads. These have been intentional-
ly designed to be slightly larger than ne-
cessary in order to facilitate soldering the
capacitor. Next, heat the previously tinned
solder pad with a soldering iron and, in
this way, “tack” it to the capacitor. If the
capacitor is sitting incorrectly, it can still
be straightened at this stage. If everything
fits, solder the negative pole and subse-
quently, the positive pole.
This is followed by IC1 (installation posi-
tion in accordance with assembly guide),
the two potentiometers P1 (1 k) and P2
(100 k) and the miniature slide switch S1.
Along with the box, the latter should sit
flat on the circuit board so that the hori-
zontal lever later fits through the opening
in the box.
Now, the protruding leads of P1, P2 and
S1 located on the solder side in the imme-
diate vicinity of the board edge, must be
carefully cut flush with the board using
wire cutters so that the board fits nicely in-
to the bottom half of the box when assem-
bled.
