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The VersaKeyer
A one-evening project based upon the
Wilderness Radio KC1 Keyer kit
Forty years ago, if someone predicted that in my midsixties
I'd get hooked on CW, I would have laughed, but it happened and I am!
So here I am, an old guy, with a hearing impairment and a lousy fist,
shopping around for an inexpensive keyer. Well, fortunately for me, Wayne
Burdick, N6KR, designed a delightful little keyer a couple of years ago,
and it was available in kit form from Wilderness Radio. This terrific
little kit, called the KC1, was inexpensive; the assembled unit was very
small (about the size of a stick of gum); and it delivered amazing performance:
Iambic keyer, RF counter using Morse output, message memories, and very
low power consumption (7 to 16 Volts @ 5mA).
Although the KC1 was designed to be incorporated within
a QRP transceiver, with a few minor additions I transformed it into a
terrific standalone, battery-operated keyer with some very impressive
extras. In fact, I even added one of my own: it can also be used for code
practice. Since it is very compact and batteryoperated, you can slip it
in your pocket, along with one of the great miniature paddles, such as
the Paddlette, and train your fist whenever an opportunity arises. This
article describes the little standalone unit I assembled utilizing the
KC1, and I've dubbed it the VersaKeyer.
Preparing the enclosure
The original VersaKeyer was built into a small plastic box
4" X 5" X 2", but if you have good vision and steady hands,
and would rather use an earphone, the whole unit could be built into a
much smaller enclosure.
The KC1 manual includes a template for centerpunching the
holes for the KC1 controls. The KC1 mounts to the front panel using the
nuts on the programming switches. If you use a plastic enclosure, it is
recommended that you use a small piece of pc board inside the box to provide
a good ground for the BNC connector, to mount the divider for the RF counter
input, to solder the coax braids, and make other ground connections. On
the original VersaKeyer, the piezo speaker was mounted inside the enclosure,
and the installation required only a 5/16" hole in the center for
sound output. If your enclosure is too tight for that, simply mount the
piezo speaker on the outside. Mount all parts except the KC1.
Wiring the VersaKeyer
Referring to Figure 1, note that the only modification to
the KC1 itself is that C6 is changed from a .001mF to a 0.1mF. In addition,
do not install ground jumpers at B1 or B2. Mount all parts on the KC1
pc board according to the KC1 Assembly Manual. Measure and prepare the
interconnecting wires. Initially, make the wires significantly longer
than they need to be (you can trim the excess later when connecting their
bitter ends). It is also a good idea to leave enough excess length to
allow you to form the interconnecting wires into bundles using small nylon
ties. Use small, flexible coax cable for both the RF counter and piezo
speaker wires. Solder and label all interconnecting wires to the KC1 pc
board. Now mount the KC1 into the holes previously prepared. Complete
the wiring by soldering the bitter ends of the wires to the appropriate
switches, jacks, etc.
Preliminary checkout
With any electronic construction project, it's a good idea
to perform preliminary checks before applying power. Begin by making visual
checks looking for solder bridges, splashes, etc. Visually check the coax
connections - especially the braids because stray strands can cause short
circuits; then prior to connecting the battery, attach an ohmmeter to
the battery connector's terminals, and turn the power switch to its ON
position. The ohmmeter should indicate a nearinfinite resistance.
Programming the KC1
The KC1 is basically a microcontroller - and it can perform
wonderful tasks! But you must first program it. The instructions and data
are input by the pushbutton switches and the paddle. The KC1 manual contains
detailed programming instructions; read and follow them carefully. Don't
try to shortcut the process; I did, and ended up having to call Wilderness
Radio for tech support. Just remember: it's all in the manual. During
the programming process, it will not be necessary to connect the VersaKeyer
to a rig-the piezo speaker will provide the tones needed to indicate performance.
Important: program the counter as instructed for direct conversion transceivers
(o3A000).
Measuring frequency
The RF Counter input voltage divider was calculated to support
voltage levels present in QRP operation from 0.5 to 5.0 Watts into 50
Ohms. If you desire to measure higher levels, the divider should be redesigned
accordingly. The keyer function can be safely used with any amateur transmitter
employing key to ground keying. Note that the VersaKeyer depicted in the
photos employs a single BNC female connector. In operation, a BNC Tee
adapter fitting is used, and connections are made as shown in Figure 2.
Connected in this manner, a small sample of the RF voltage is taken and
supplied to the KC1 frequency input, and the measured frequency is indicated
in Morse characters heard through the piezo speaker.
Operational checkout
With the VersaKeyer and transceiver connected as shown in
Figure 2, turn both units ON. While depressing the Tune pushbutton on
the VersaKeyer, momentarily push the Frequency pushbutton: the output
frequency will be read out in Morse characters. Now check the operation
of the paddle and set the speed control as desired.
Summary
Although the VersaKeyer is a simple construction project,
it has many useful features. This is because of Wayne Burdick's clever
design of the KC1. The VersaKeyer makes an excellent keyer for almost
any amateur application, and operating from its internal 9-volt battery,
- with miserly power consumption. It also eliminates a lot of clutter
(such as another power cord or wall unit to be plugged in).
- Dave Evison, W7DE, can be reached at
153 Park Avenue, Palo Alto, CA 94306; w7de@aol.com.
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