Elecraft KX1 Manual - Manual (Page 42)

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LECRAFT 41
Strip the insulation and tin the leads of both inductors using one
of the following techniques:
1. Heat Stripping:
a. Place a small amount of solder (a.k.a. a “blob” of solder)
on your soldering iron.
b. Insert the clipped end of the wire into the hot solder. If the
iron is hot enough, you should see the insulation bubble
and vaporize after 4 to 6 seconds.
c. Add more solder and feed more wire into the solder as the
enamel melts. Continue tinning the wire up to the edge of
the core, and then slowly pull the wire out of the solder.
d. If any enamel remains on the lead, scrape it away using
your thumbnail or sharp tool.
2. Burning: The insulation can be burned off by heating it with a
butane lighter for a few seconds. Use sandpaper to remove the
residue, then tin the bare wires.
3. Scraping: Use a sharp tool to scrape the insulation away. Work
carefully and gently: do not nick the wire. Work around the
entire circumference of the wire to remove all of the enamel
and tin the bare wires.
Place L2 over the printed outline on the board and thread its leads
through the solder pads.
Pull the leads tight so the toroid is sitting upright and against the
board. Check to see that some tinned lead is visible above the pad near
the toroid when the wire is pulled tight. If necessary, remove the toroid
and tin the lead closer to the core. It won’t matter of the tinned wire
touches the core itself. The toroid core is not a conductor.
Solder both leads.
Use your DMM to check for continuity across the solder pads. It
should be less than 1 ohm. If it is higher, you probably have a poorly
tinned toroid lead. Sometimes the leads look like they are soldered, but
because there is a film of enamel still on the lead, it is not making
contact with the solder pad. If the resistance is greater than 1 ohm,
remove the toroid, clean and re-tin the leads and reinstall it.
Wind and install L1 using the same procedure except that L1 has
13 turns. Use the second yellow toroid core for L1.
i
Do NOT attach L1 or L2 to the circuit board with
adhesive, varnish, etc. The toroids will be adequately supported by
their leads. Adhesives or other compounds may damage the
enamel wire.
Bend a discarded 1/4-watt resistor lead into a “U” shape and
insert it into J7 pins 1 and 3 (J7 is the 3-pin connector adjacent to
antenna jack J1; do not insert the wire into the 2-pin connector, J8).
This jumper completes the antenna circuit when the optional KXAT1
ATU is not installed.