Elecraft KRC2 Manual - Manual (Page 8)

8
Install the following resistors on the top side of the circuit board. Be sure to use the 4.7k 1/4
watt resistor at R12. The smaller 1/8 watt resistor will be used later.
__R1 47k, (yel-vio-org)
__R3 1k, (brn-blk-red)
__R4 470 ohms, (yel-vio-brn)
__R6 10K (brn-blk-org)
__R7 10K, (brn-blk-org)
__R8 10K, (brn-blk-org)
__R9 100 ohms, (brn-blk-brn)
__R10 10K, (brn-blk-org)
__R12 4.7K, 1/4 watt (yel-vio-red)
__R13 47 ohms, (yel-vio-blk)
Install two 1N4007 diodes D4 and D5 on the top side of the board. Make sure the cathode
(banded end) of the diodes follow the same orientation as that silk-screened on the PCB then
solder and trim the leads. D5 must be flush-trimmed on the bottom side in order not to interfere
with J5. Be sure to save these cut leads for later use as ground jumpers.
__D4, __D5
Install the following 1N4148 diodes on the top side of the board. Make sure the cathode
(banded end) of each diode follows the same orientation as that silk-screened on the PCB, then
solder and trim the leads.
__D6, __D7, __D8, __D9, __D10
i
Before handling ICs and transistors, touch an unpainted, grounded metal surface.
Install voltage regulator U3 (78L05C) on the top side of the board as indicated by its outline.
The voltage regulator has a 3-pin TO-92 package, like a transistor. The installed height of the
regulator must be no more than 3/8" (9 mm). Use a minimum of soldering time (1-2 seconds per
lead).
Locate the four pushbutton switches. One of these will now be installed on the top side of the
board. Insert the switch into its mounting holes at S1, spreading the legs slightly so they will
properly engage the holes. Press the switch down until it is fully seated on the bends in its leads.
When the switch is fully seated, there will be a slight gap between the switch body and PCB. This
is normal. Solder the switch onto the circuit board from the bottom side.