3CPO Code Practice Oscillator / Keyer / Trainer


3CPO has been retired.

Please check out our new replacement Mini-Yack 2d

or the bare bones Mini-Yack kit

3CPO combines a keyer, Twin-T oscillator, and transmitter keying circuits into a single unit.

  • Modified DK3LJ YACK memory keyer IC
  • IAMBIC key training mode – learn how to send with a keyer!
  • NEW UPDATED – Advanced IAMBIC training mode – code will speed up or slow down as you make correct or incorrect entries.  When you are done a score of your results is played back.  Training modes now support complex calls from a simple 1×1 (W1A) to a 2×3 w/ prefix or suffix (VK4AAA/VP7 or G4/W9ABC).
  • NEW – Straight key detection.  Just plug a straight key with mono jack in and 3CPO will automatically go into straight key mode on power up.
  • Beacon mode
  • NEW Fox hunt mode turns the on-off-on keying into a full time key down to use with FM transmitters.
  • QRS button
  • Twin-T oscillator with wave shape circuitry provides a near sine wave signal properly shaped for CW
  • Audio tone range: 300-1,000Hz
  • Ability to key many rigs using both positive and negative grid key interfaces.  Tested on:
    • Heathkit HW-7, HW-8, HW-16
    • Icom IC-271, IC-725
    • Kenwood TS-520 TS-530
    • Yaesu FT-290RII
    • 4SQRP SS-40 and Cyclone
  • Protection circuitry on the keyer input and power supply polarity.
  • Hardware reset to factory defaults.
  • Kit includes instruction manual, all parts, connectors, speaker, and enclosure.

Click here for 3CPO-Manual, Schematics, and Operation manuals.

3CPO Source

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Kit, Assembled


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