‰  NOW 25 WPM  ‰  TEXT IS FROM NOVEMBER 2012 QST  PAGE 55‰

SHOWN IN THE SCHEMATIC.  IF YOU USE RELAYS THAT LACK THE INTERNAL DIODE,
YOU WILL HAVE TO WIRE DIODES ACROSS EACH OF THE COILS, PAYING ATTENTION TO
THE ORIENTATION OF THE DIODES AS INDICATED IN THE SCHEMATIC.  ANY AVAILABLE
DIODES IN THE 1N400X SERIES CAN BE USED.  THERE IS WIDE LATITUDE FOR RELAY
SUBSTITUTION.  I CHOSE RELAYS WITH 12 V DC COILS BECAUSE IT WAS EASY TO
POWER THE UNIT FROM ONE OF THE UBIQUITOUS 12 V WALL WART POWER SUPPLIES OR
FROM THE MAIN STATION POWER SUPPLY.  RELAYS WITH 5 V DC COILS COULD BE
USED, BUT WOULD REQUIRE THE USE OF A 5 V REGULATOR.  THE ENTIRE PROJECT
COULD EASILY BE POWERED FROM A 5 V BUS IF DESIRED, BUT THAT WOULD REQUIRE
THAT EACH OF THE FOUR 1200 RESISTORS BE REPLACED WITH 470 RESISTORS TO
PROVIDE SUFFICIENT CURRENT FOR THE FRONT PANEL LEDS AND THE LED IN THE
OPTICALLY TRIGGERED SWITCHES IN K3.  J3 THROUGH J5 ARE RCA TYPE PHONO
JACKS.  WIDELY AVAILABLE AUDIO CABLES CAN BE USED FOR INTERCONNECTIONS.
‰  END OF 25 WPM TEXT  ‰  QST DE W1AW  ƒ