AAØZZ EZKeyer III 23 November 2014
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Copyright 2014 AAØZZ
directly with the paddles rather than scrolling through menus. The printed circuit board, case, and PIC
microcontroller code were designed and developed for the Four State QRP Group by Craig Johnson,
AAØZZ.
Using a PC board that is only 2" x 2", this is an EZ-to-build, small footprint project with large impact on
your operating capabilities, whether in the shack or in the field. This version features a custom case that
the builder assembles from PC boards. All installation instructions are included in this assembly manual.
The kit includes all the parts required to build the kit – printed circuit board, pushbuttons, connectors,
speaker, programmed PIC microcontroller, transistors, caps, diodes and an easy-to-assemble custom
case.
2 Features
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PIC microcontroller (16F88)
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Speed controlled by potentiometer or via the paddles
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Speed range 5 - 55 words per minute
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Eleven direct-entry commands
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Three easy-to-use memories stored in non-volatile memory (EEPROM). Messages 1 can hold up
to 47 characters while messages 2 and 3 can each hold up to 95 characters
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Iambic A or B, bug emulation, straight-key (“cootie-key”) modes
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Sequenced receiver mute line (low active for 7ms before and after keying the transmitter)
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Speed and modes saved in non-volatile memory (EEPROM)
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Speed entered by command or changed on-the-fly via the paddles
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Tune mode
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Current speed reported by command
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600 Hz sidetone (may be turned off)
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Autospacing between elements of characters (optional)
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Paddle Dash/Dot swap command
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Current code revision can found when powering up
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All EEPROM setting can be initialized to default settings
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Message repeat after selectable delay (beacon mode) of up to 9 seconds
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Operating voltage 3 - 5.5 volts
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Low power (1ma active and 1uA in sleep mode)so no power switch required
3
Components
___ 18-pin PIC Socket
___ U1 - 16LF88 PIC
___ C1 - .1 uF Capacitor
___ Q1, Q2 - BS170 N-Chan MOSFET transistor - flat side must match outline on board
___ D1, D2 - 1N4148 diode - orient banded end per silk-screen on board
___ D3 - 1N5817 Schottky Diode
___ J1 - 1/8” Stereo jack - Paddle input — tip dot, dash ring, ground sleeve
___ J2 - 1/8” Stereo jack - Keyed line — line connected to tip, ground to sleeve
___ J3 - 1/8” Stereo jack – RX Mute line — mute connected to tip, ground to sleeve
___ R1 -10k linear potentiometer
___ R1 -10k trimmer potentiometer
___ Spk1 Speaker
___ PB1, PB2, PB3 SPST momentary-on pushbuttons
___ PC board
___ Case
___ 4 rubber bumpers