‰ NOW 15 WPM ‰ TEXT IS FROM SEPTEMBER 2017 QST PAGE 37 ‰ TEST THE ASSEMBLY. A DUAL CHANNEL OSCILLOSCOPE AND DIGITAL VOLTMETER ARE HANDY TOOLS FOR CHECKING THE LEVELS AT THE KEYER PORT. BEFORE CONNECTING THE INTERFACE TO THE RADIO, APPLY POWER TO THE PORTABLE KEYBOARD INTERFACE AND MEASURE THE VOLTAGE AT THE TWO PADDLE CONNECTIONS. TYPE A FEW CHARACTERS ON THE KEYBOARD. THE VOLTAGE LEVEL AT THE DIT AND DAH PINS SHOULD REMAIN ZERO. REMOVE POWER FROM THE PORTABLE KEYBOARD INTERFACE. VERIFY THAT THE VOLTAGE AT THE DIT AND DAH PINS OF YOUR RADIO KEYER PADDLE ‰ END OF 15 WPM TEXT ‚