MFJ MFJ-561K User manual

MFJ-561K Travel Iambic Paddle Kit
INTRODUCTION
Your new Travel Iambic Paddle is a great addition to any CW collection. Its
small, lightweight frame makes it ideal for traveling. Just plug your pocket-
sized paddle into your favorite keyer or rig and you are ready to send smooth
CW from almost anywhere.
This kit is a very simple one that can be constructed by the most novice of kit
builders. By following the instructions carefully, you should be able to
assemble the paddle and send CW in no time. Though the paddle is universal to
most transceivers, MFJ recommends that the paddle be used with compatible
MFJ products. With whatever keyer or rig you use, verify that it has a 3.5 mm
jack input.
BEFORE YOU START BUILDING
Construction Area: Kit construction requires a clean, smooth, and well-lighted
area where you can easily organize and handle small parts without losing them.
An inexpensive sheet of white poster board makes an excellent construction
surface, while providing protection for the underlying table or desk. Good
overhead lighting is a plus, and a supplemental high-intensity desk lamp will
prove especially helpful for close-up work. Safety is also an important
consideration. Be sure to use a suitable high-temperature stand for your
soldering iron, and keep the work area free of combustible clutter.
Tools Needed: While assembling this kit you will need a work area outfitted
with the following tools and supplies:
Phillips Head Screwdriver
30 to 60 Watt Soldering Iron
High-temperature Iron Holder with Moist Cleaning Sponge
Rosin-core Solder (thin wire-size preferred)
Needle Nose Pliers or Surgical Hemostats

MFJ-561K Travel Iambic Paddle Kit
surfaces to be connected are hot. Then, feed the solder around the lead causing
the solder to wick up, wetting all exposed surfaces.
Desoldering Tips: If you make a mistake in soldering and need to correct a
step, follow these instructions carefully. First, grasp the part to be removed with
a pair of hemostats or needle-nose pliers. Heat the solder joint until the solder
loosens and pull gently. The lead should then be able to be extracted. Repeat
this process for any other bad connections.
PARTS LIST
Your kit should contain all of the parts listed below. Please identify and
inventory each part on the checklist before you start building. If any parts are
missing or damaged, refer to the manual’s warranty section for replacement
instructions.
;Qty Part Description Part Number
1 Paddle Base 738-0561
1 Paddle 735-0561
4 Phillips Head Screws 654-0250S
3 Solder Lugs (Aluminum Tabs) 720D-0621L
2 Washers 714-0631
2 Shoulder Washers 7145-0421N
3 Kep Nuts 705-0440-K
1 Open-end 3.5 mm Stereo Cable 620-8005
1 Spacer 715B-0500S
6 Rubber Feet 770-1162
1 Wire Tie 745-2149

MFJ-561K Travel Iambic Paddle Kit
1. Insert the shoulder washer into the hole on the side of the paddle facing
out. Make sure that the shoulder is completely inside the hole and the
washer is flush with the paddle.
2. Next, insert a screw into the hole from the inside out. On the outside of
paddle, place a washer, a solder lug and then a kep nut on the screw.
Be sure to tighten it with the solder lug facing away from the arms of
the paddle, parallel to where the base goes (see Figure 1).
3. Repeat steps 1 and 2 for the other side. Make sure that the solder lugs
are not in contact with the paddle. The washers are provided to insulate
the screw, solder lug and kep nut from the paddle.
Figure 1

MFJ-561K Travel Iambic Paddle Kit
4. Place the Paddle on its base and then fasten. First, secure the back of
the paddle with a screw and kep nut. Then, place the spacer between
the paddle’s arms and secure it from the bottom with the screw and the
remaining solder lug (see Figure 2 and 4). Be certain that all screws
and nuts are tight before proceeding. Make sure there is a small gap
between the spacer and the screw heads.
Figure 2
Spacer
Base
Paddle Arm
Rubber Foot
The next steps require soldering. For tips on soldering refer to BEFORE YOU
START BUILDING portion of the manual.
Caution: When heated, soldering irons and solder can seriously burn anything
they contact.
5. Prepare the wire of the 3.5 mm jack to be connected to the Iambic

MFJ-561K Travel Iambic Paddle Kit
Figure 4
Tip
Ring
Common
7. Flip the paddle over so that the bottom is facing up. Then, lay the wire
along the bottom side of the paddle (see Figure 4).
8. Use Figures 3 and 4 to orient the wires to their correct positions. With
the paddle positioned like Figure 4, run the wire that corresponds to the
tip through the upper hole, the ring through the bottom hole, and the
common to the solder lug located on the base.
9. Solder the common wire to the solder lug on the bottom of the base and
let cool.
10. Flip the paddle back right side up and pull each wire to the
corresponding solder lug on either side of the paddle.
11. Solder the wires one at a time to the corresponding solder lugs on either
side of the paddle and let cool. Make sure that the wires do not make a
connection with the paddle arms.

MFJ-561K Travel Iambic Paddle Kit
TROUBLESHOOTING
If your paddle does not function properly, proceed with the following steps.
Refer to Figures 1, 2, and 3 to ensure that your paddle is assembled correctly.
Make sure that all screws and nuts are secure.
Check all solder marks for flaws.
Be sure that all the leads of the wires are properly connected (see steps 4-10
and Figures 3 and 4).
Make sure the 3.5 mm jack is plugged correctly in your keyer or rig and that
the keyer or rig is properly turned on.
Be sure that there is a gap between the spacer and the screw heads.
Make sure that the shoulder washer is completely inside the hole on the
paddle and the washer is flush with the paddle.
If none of these steps help, go back through the assembly instructions to insure
that the kit was properly assembled. If the kit does not work after this, contact
your local MFJ distributor for product assistance.