Elecraft KDSP2 Manual - Manual (Page 16)

16
Using solder wick or a desoldering pump, carefully clean out the holes of solder where the leads of
R18 and R19 were. DO NOT overheat the pads.
Install the 5-pin female header (1 row of 5 terminals) at J1 on the component side of the Control
Board. The connector must be seated flush to the PCB and perpendicular to it. Solder the center pin only.
Install the 3-pin female header (1 row of 3 terminals) at J2 on the component side of the Control
Board. The connector must be seated flush to the PCB and perpendicular to it. Solder the center pin only.
Inspect the installation and verify the connectors are flush to the board and perpendicular to it.
Solder the remaining pins of J1 and J2.
Examine the electrolytic capacitors on the Control Board from the right hand side of the
microcontroller (U6) to the right edge of the PCB. Ensure that these parts, and any other tall parts in the
area, are firmly seated to the PCB and are straight. Clearance is tight between the KDSP2 and the Control
Board, and you must take care to ensure no shorts will develop.
Plug the Control Board into the K2 RF Board.
Installation
The Control Board is held in place with two 4-40 screws. The screw nearer J1 and J2 will be replaced with
the male-female threaded spacer provided with the KDSP2 kit.
If you have previously installed a KAF2 in your K2, remove it and skip the next two steps.
Thread the ½” (12mm) threaded spacer through the mounting hole in the Control Board nearer J1 and
J2. Tighten it snugly by hand. Do not overtighten - the spacer is made of aluminum and can be damaged
by less torque than you might think.
Verify the other mounting hole of the Control Board is secured with K2-supplied 4-40 hardware.
Remove Frequency Counter cable (used for CAL operations) if present.
Plug the KDSP2 board into the control board. Clearance between the KDSP2 and the cabinet side
panel may be very tight.
Ensure that the pins going into J1 and J2 are aligned properly. Misalignment (being off by one or
more pins in either direction) may result in damage to the K2, the KDSP2, or both. If the mounting hole in
the KDSP2 does not line up with the threaded hole in the spacer just installed, you may have the KDSP2
improperly mated with J1 and J2. Re-check.
Check that the KDSP2 board doesn’t interfere with the grounding wire on the PLL reference crystal(
X1 on the RF board). The grounding wire for this crystal should be on the side of the crystal, not the top.
If it is on the top, you should move it to the side of the crystal.