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quick'n'dirty patch box to connect a variety of keys and paddles
to a single electronic keyer or code practice oscillator.
includes a showroom where folks can lay hands on a variety of keys,
bugs, paddles, and associated keying equipment. The demo keyer is
the LogiKey K5, which also
functions as a code practice oscillator. Equally useful would be the GHD GR301A Morse Training Unit, which is designed first as a code practice oscillator but includes a practice keyer. I also have a Katsumi EKM2B
code practice oscillator which direct-connects to the binding posts on
keys, but it could as easily be connected to the patch box.
Several of the keys are
demonstrated more frequently than others, so a single box to plug the
keys and paddles into seemed to be a very useful idea. And it can be
adapted to shack situations where you want to connect more than one
keying device to a single radio.
Keys, bugs, and paddles come with a variety of connection methods.
Some have binding posts, some have cables with plugs on
them, some have cables which require you to attach a plug, and
some have solder terminals for permanent connection of the cable.
paddles will always be "stereo" or two conductors plus a shield or
"common" wire. Plugs for keys can be stereo or mono, or RCA.
Stereo and mono phone plugs can be 1/8" or 1/4".
In order to simplify, I went with the most common-- 1/8" stereo jacks,
with 6 of them wired for "mono" plugs and six for stereo. In a more permanent installation (e.g. a radio shack) I
would install the specific jacks required for my equipment.
In many cases a mono plug cannot be used in a stereo jack. That's
because the plug will short the ring connection to the sleeve inside the jack. In
other cases the ring connection is not used, so it
doesn't matter. There is a surprising variety of possible
combinations of plug type, conductors, and wiring, but electrically the
circuit is very simple and easy to diagnose or verify with a multimeter
or even by trial and error.
I didn't have a lot of time for this so I went with materials that were on hand and easy to work with.
Project box: MX-H804 6x3x1 Hammond molded styrene with cover
Cable for keyer: MX-C8S 3' shielded, 1/8" stereo plug.
Jacks for keys and paddles: 1/8" stereo panel jacks
Wire: 20 awg tinned bus wire or any convenient hookup wire, about 18"
decided to set up 6 jacks for
paddles (stereo) and 6 for keys (mono), and drilled the holes in the
lid more or less free-hand-- I drew two lines along the axis of the
jacks, and marked the individual jack positions with a pencil. Of
course you could make a drilling
template and label if you are concerned about how it looks.
for the related Control Panel article.)
The connecting cable enters through a hole in the end of the box and can be secured with a cable tie or a blob of hot-melt glue.
bus wire is very easy to work
with in this situation, as it is a continuous run that is soldered to
the appropriate terminals on the jacks. If you use ordinary
hookup wire you will need to cut small pieces to go between the jacks,
or strip "spots" along a continuous wire.
the case of the jacks to be used with
mono plugs (straight keys), the ring connection is not used. I
tip connections in common with the ring connections on the jacks to
be used with stereo plugs (paddles). With the Logikey Keyer in
"hand key mode" either the tip or ring (dot or dash side on the paddle)
will act as a straight key, but many keyers and radios require the use
of "bug mode" in which case only the dash line acts as a straight key.
In that situation the plug would need to be stereo, and you would plug
it into one of the stereo "paddle" jacks.