Elecraft K1 - Manual (Page 43)

42
E
LECRAFT
8. RF Board, Part II
In this section you’ll install the transmitter components.
Turn off the K1 and disconnect the power supply.
Unplug the Filter board and set it aside.
i
If you have difficulty installing components in the
remaining assembly steps, unplug the Front Panel assembly and
remove the side panels.
Install the following capacitors, starting with C3, which is in
the back-left corner of the RF board.
__ C3, 10 (10)
⇒
__ C62, 330 (331)
⇒
__ C56, .047 (473)
__ C15, .001 (102) __ C58, .01 (103) __ C51, .001 (102)
__ C14, .001 (102) __ C16, .001 (102) __ C60, .01 (103)
__ C76, .01 (103) __ C57, .047 (473) __ C47, .01 (103)
__ C44, .01 (103) __ C46, 0.1 (104) __ C50, .047 (473)
__ C55, 0.1 (104) __ C52, 0.1 (104) __ C43, .01 (103)
Install the following 5% resistors, starting with R35 on the left
side of the board near J6.
__ R35, 120 (BRN-RED-BRN)
⇒
__ R10, 470 (YEL-VIO-BRN)
__ R11, 82 (GRAY-RED-BLK) __ R22, 33 (ORG-ORG-BLK)
__ R12, 820 (GRAY-RED-BRN) __ R24, 2.7 k (RED-VIO-RED)
__ R38, 270 (RED-VIO-BRN)
__ R28, 820 (GRAY-RED-BRN)
__ R29, 270 (RED-VIO-BRN) __ R30, 3.3 Ω (ORG-ORG-GOLD)
__ R33, 470 (YEL-VIO-BRN) __ R25, 100 k (BRN-BLK-YEL)
__ R31, 33 (ORG-ORG-BLK) __ R32, 33 (ORG-ORG-BLK)
On the bottom of the board near the antenna jack, install a
1.50 k, 1% resistor at R36 (BRN-GRN-BLK-BRN), and a 226-ohm,
1% resistor at R37 (RED-RED-BLU-BLK).
i
Be sure to check the orientation of the banded end of each
diode in the following steps.
Install the 36-volt zener diode, D19 (type 1N4753), which has
a large glass or silver-colored body. D19 is on the right side of the
board, between transformers T3 and T4 (not yet installed).
The remaining diodes to be installed are all type 1N4007. D18
is on the left side of the board, near J6.
__ D18 __ D14 __ D13 __ D9
Install a 100-µH RF choke (BRN-BLK-BRN) at RFC3 (located
near S1).
Install 22-µH RF chokes (RED-RED-BLK) at RFC2 and RFC5.
Refer to Figure 5-4 (page 19) when installing these transistors.
__ Q5, J309 (near J6) __ Q14, 2N4124 (back-left corner)
Install C1 (150 pF, “151”) on the bottom of the board. Before
soldering, fold C1 down towards the pads of R31 and R32 (but make
sure it isn’t touching these pads). C1’s overall height should be no
more than 0.15” (4 mm) above the bottom of the board.