Using CheX

CheX is a FREE interactive Morse code tester and exerciser. It can be used on a stand-alone basis but was developed specifically to provide an interactive on-line code tutor that is integrated with your book listening session.

It is based on the highly effective Koch method and enhanced to provide instantaneous visual feedback. Most importantly, it monitors performance and continuously modifies the content of the drill session to target your problem characters.

Note: You must have a modern browser for CheX to run properly. Also, you must enable JavaScript in your browser options.

  • CheX tests your ability to decode Morse code sent at 15-30 wpm.
  • Recognizes your problem characters and drills accordingly until you learn them.
  • Links the characteristic sound of code to the corresponding printed character.
  • Provides instant visual feedback when a character is selected.
  • Develops your ability to remember random groups of ciphers like call signs.
  • Shows your score as soon as you finish a group so you know when you’re ready to add the next Morse character in your novel listening session. (Only add an additional character after you consistently score 100%!)

How to use CheX

  • Check off the characters you want to include in your practice session. If you are a subscriber, Chex will open with your listening session’s Morse code characters and wpm speed already selected. But you can change the selections at any time.
  • Select Morse or vocalized English. The latter is useful for memory training before you know many Morse characters.
  • Select the code speed (15-30 wpm) and group length (2-15 characters).
  • Select the number of times the group is to be sent (1-6) and the spacing between each repetition (Normal, 2x, 4x). This feature is targeted at call sign practice.
  • Click on “Get group.” After a short interval, the familiar player will appear. Press the Play arrow. Use your mouse to click on the QWERTY keyboard.
  • The keyboard button will flash green on a correct entry and red otherwise.
  • After you’ve entered all the characters in the group, both the sent group and your entries will be displayed (green for correct ones, red for incorrect), along with your percentage score. Your score will decrease if you enter more characters than were sent! You can replay the group of characters by using the play button on the player.

  • Click on “Get group” to get the next group of characters. The player will flash briefly to let you know it’s ready with a new string of characters.

No, you can’t use your physical keyboard! CheX is not a typing tutor. It’s the “hunt and peck” process that you have to use on the embedded keyboard that subconsciously links the sound of a Morse character with its alphanumeric visual representation. And the color change of the clicked key will provide immediate feedback to reinforce your learning.

The software will keep track of your misses and will adjust the statistical distribution of the characters sent in order to target your problem areas. It will revert to a uniform distribution once you no longer err on those characters.