T-238 Assembly Manual
Rev. 1 February 2001
Page 5 of 11
LEDs are polarized components. The flat side on the base
and the shorter lead identifies the cathode lead. Insert the
LED according to the silk-screen outline, the flat side or
short lead to the flat side of the silkscreen
.
[ ] DS2 Red LED
[ ] Solder and clip the leads (2 total)
Male Headers
The male headers will be installed next. The plastic body of
the part should rest flush with the top surface of the PC
board. Note that the short end of the pins go into the PC
board, the long end sticks up.
WARNING!
–
Do not hold these parts with your fingers
while soldering. The pins get very hot.
Place a 2-pin jumper on the header to insulate your finger
from the pins, hold the header in place and tack solder one
pin. Check for proper alignment. If alignment is off, you
can reheat the one pin to adjust. Once the alignment is
correct, solder the rest of the pins and then reflow (reheat)
the first pin you soldered.
[ ] OJ1 1x3 male header
[ ] OJ2 1x3 male header
[ ] J6 2x8 male header
[ ] J9 2x5 male header
Header J10 is a 1x16-pin male header. A 1x17-pin male
header is supplied in the kit. Carefully trim 1 pin off one
end of the header to make a 1x16-pin header.
[ ] Trim 1x17-pin male header to 1x16-pins.
[ ] Solder the 1x16-pin male header to J10.
Header J8 is a polarized 2-pin male header. Align J8 to
the silkscreen on the PCB and then solder.
[ ] J8 1x2 male header, polarized
Jumpers
Install the 2-pin push-on jumpers in the following locations:
[ ] OJ1 short pins 1 and 2 (center to left)
[ ] OJ2 short pins 1 and 2 (center to left)
Crystal Oscillators
Install the following crystal oscillators. The orientation of
these devices is important. Pin 1 is marked on the PCB
with a square pad. Pin 1 on the crystal oscillator is marked
with a black dot and/or an edge of the can that is square
instead of rounded.
CAUTION! –
Make certain that the U1 metal housing does
not short to nearby R10 or R12.
[ ] U1 32.000 MHz
[ ] U2 9.8304 MHz
[ ] Solder and clip the leads (8 total)
Connectors
Gently rock the RJ-11 connector until it snaps into place
and solder the leads.
[ ] J2 RJ-11 connector
CAUTION!
–
Soldering the coaxial power connector is a bit
tricky because of the large mounting holes.
[ ] J1 Coaxial power connector
Install the DE-9 connectors in their respective locations.
Secure the connectors using two 4-40 x 3/8” screws and 4-
40 nuts per connector before soldering the pins.
[ ] J3 DE-9 female
[ ] J4 DE-9 female
[ ] J5 DE-9 male
[ ] Solder the leads
Switches
Install four round miniature SPST momentary switches.
Position them according to the silkscreen and solder the
leads and body mounting pins. The polarity of the switches
is important. Note that on the silkscreen the flat side of the
switch faces the edge of the PCB.
[ ] SW1 SPST Momentary Push Button
[ ] SW2 SPST Momentary Push Button
[ ] SW3 SPST Momentary Push Button
[ ] SW4 SPST Momentary Push Button
[ ] Solder the leads
Install one square DPDT momentary switch. The position
of the switch in not polarity sensitive.
[ ] SW5 DPDT Momentary Push Button
[ ] Solder the leads
Voltage Regulator Heatsink
Align the heatsink on the regulator and attached it using
the 4-40 x ¼” screw and one nuts to secure the two.
[ ] Mount and bolt the heatsink to the regulator.
Voltage Regulator
NOTE –
Voltage regulators are polarized components.
Match the body of the voltage regulator with the silk-
screened outline. The metal tab should be toward the
outside of the board. Carefully bend the leads to match the
hole pattern on the PC board. The bottom of the body of
the voltage regulator should not be more that 1/4” above
the PC board.