‰  NOW 35 WPM  ‰  TEXT IS FROM JUNE 2015 QST  PAGE 55‰

fA SEMIAUTOMATIC TUNER THE WAY THE AT 615B WORKS IS THAT THE OPERATOR FIRST
MANUALLY PRELOADS OPTIMIZED TUNER SETTINGS CORRESPONDING TO THE TUNERS 85
FREQUENCY BINS.  THE BINS ARE 20 KHZ WIDE ON 160 METERS, INCREASING TO 100
KHZ WIDE ON 10 METERS.  I USED MY ANTENNA ANALYZER TO GENERATE THE SIGNALS
AND MEASURE THE SWR AT THE CENTER FREQUENCY OF EACH OF THE FREQUENCY BINS.
AFTER ADJUSTING THE AT 615B FOR MINIMUM SWR, I ENTERED THE SETTINGS INTO
MEMORY AND ADDRESSED THE NEXT BIN.  AFTER THE MEMORIES ARE ALL LOADED, THE
CONTROL UNIT FUNCTION SWITCH IS MOVED FROM MANUAL TO AUTOMATIC AND THE
MEMORY SWITCH IS SET FROM TUNE TO MEMORY.  TRANSMITTING A SIGNAL TOWARD THE
TUNER WITH THE FREQUENCY SENSOR IN LINE ALLOWS THE CONTROL HEAD TO MEASURE
THE FREQUENCY.  THE AT 615B THEN AUTOMATICALLY CHANGES THE TUNING TO THE
MEMORIZED SETTING CORRESPONDING TO THE BIN CLOSEST TO THE MEASURED
FREQUENCY.  OVERVIEW THE TUNER AND CONTROLLER APPEAR TO BE WELL THOUGHT OUT
AND WELL MADE.  THE CONTROL UNIT FIGURE 1 INCLUDES A TWO LINE DISPLAY WITH
THE TOP LINE SHOWING THE FREQUENCY BIN, EITHER SET MANUALLY WHILE MAKING
ADJUSTMENTS, OR AS DETECTED BY THE RF SENSOR.  THE SECOND LINE SHOWS THE
POSITIONS OF THE THREE TUNING CONTROLS OF THE BALANCED NETWORK TUNING
SYSTEM.  THE CONTROLLER ALSO INCLUDES A KEYING LINE FOR THE POWER AMPLIFIER
TO INHIBIT FULL POWER OPERATION WHILE THE AT 615B IS TUNING.  THE CONTROL
‰  END OF 35 WPM TEXT  ‰  QST DE W1AW  ƒ