PicoKeyer-Plus
05/25/2014 (Firmware V4.5)
Page 5 of 19
using Ultimatic mode. It’s a little bit of an adjustment from regular iambic keying; it took me a couple of hours of
practice to get used to it.
Selecting a keying mode (A, B or Ultimatic) is largely a matter of personal preference. There is no one “right” way
that works for everyone; find which works best for you.
Using Your Keyer with a Handheld or FM Rig (“MCW” Mode)
One of the unique features of your PicoKeyer-Plus is MCW mode (menu option “T” for sidetone, select “M” for
MCW). In this mode, the keying output can be used to trigger the PTT input of a VHF or UHF handie-talkie or FM
mobile rig, allowing you to use your FM rig for Morse code. This is not CW (Continuous Wave) operation, nor is
it true MCW (Modulated CW) mode – it’s really just an FM transmission, with audio Morse code tones sent instead
of voice. This makes it easy, for example, to have a CW practice net using a local repeater – with the blessing of
the repeater operator, of course – or a simplex frequency. Those participating don’t need HF privileges or HF
equipment to learn and practice Morse code on the air.
It is not possible to give detailed instructions for attaching your keyer to every rig on the market. You will need to
take a look at your rig’s manual to determine how the audio and PTT signals from the keyer need to be connected.
Doing it wrong could possibly damage your rig and/or your keyer! However, presented here are a few examples
that you may find useful for setting up your station for FM code practice. Refer to the operator’s manual for your
rig for specific requirements for PTT and audio.
Using MCW mode requires making soldered connections to a set of solder pads (JP1), which is located underneath
the battery holder on the PicoKeyer’s printed circuit board. You can “tack solder” wires in place using a low
wattage pencil type iron, 25-35 Watts maximum. Be sure to remove the battery before soldering.
Figure 1 - Keying Yaesu and similar HTs
In Figure 1, we see the most common method that will work with
many handheld transceivers from Alinco, Yaesu, Icom and others
that use a similar combined audio/PTT scheme. This value of the
capacitor is not critical, and can be several times smaller or larger.
A 2.2K or 2.7K Ohm resistor is used in series with the PTT line to
key the rig. In most cases, GROUND is connected to the sleeve
(barrel) of a 2.5mm stereo plug, and PTT/Audio is connected to the
tip – but again, be sure to consult your rig’s manual.
Figure 2 - Keying HTs with separate audio & PTT
Figure 2 shows the method for using with with separate audio and
PTT lines. Consult your rig’s manual for the correct plug and
wiring to use.
Figure 3 - Keying ICOM and similar HTs
The diagram in Figure 3 illustrates the method used by some
Icom handhelds. If your HT does not respond with the
circuit in Figure 1, try this one instead.
