‰  NOW 30 WPM  ‰   TEXT IS FROM JANUARY 2014 QST  PAGE 48‰

THE VFO.  THE SWITCHES FOR RIT DISPLAY AND VFO A/B ARE OPTIONAL.  CLOSING
THE RIT DISPLAY SWITCH CAUSES THE SHIFTED KEY UP FREQUENCY TO ALWAYS BE
DISPLAYED.  VFO A/B SWITCH TOGGLES BETWEEN VFO A AND VFO B.  THE
SYNTHESIZER OUTPUT CAN BE SWITCHED BETWEEN A DIRECT UNBUFFERED OUTPUT OR TO
THE INPUT OF THE BUFFER AMPLIFIER.  I USE THE UNBUFFERED OUTPUT AS A SIGNAL
GENERATOR THAT OUTPUT DOES NOT ROLL OFF AT THE HIGHER FREQUENCIES.  WHEN
USED AS A FREQUENCY GENERATOR THE SPOT SWITCH SHOULD BE IN THE UP POSITION,
ENABLING THE SPOT FUNCTION.  THE COMPLETED VFO FIGURE 1 SHOWS THE
SYNTHESIZER ROTARY ENCODER AND UP/DOWN SWITCHES MOUNTED ON THE FRONT PANEL.
THIS ALLOWS THE USE OF LARGE PUSHBUTTON SWITCHES THAT ARE EASIER TO USE AND
RESULTS IN A MUCH CLEANER LAYOUT.  THE BUFFERED OUTPUT AND UNBUFFERED
OUTPUT, RIT KEYING JACKS AND THE OUTPUT SELECT SWITCH ARE MOUNTED ON THE
BACK OF THE VFO AS SHOWN IN FIGURE 8.  I USED RCA JACKS FOR THE INPUTS AND
OUTPUTS.  INITIAL TESTING CONNECT THE VFO TO THE TRANSMITTER AND RUN A
SHIELDED CABLE AN AUDIO CABLE IS FINE FROM THE RIT KEYING OUTPUT ON THE
KEYING CIRCUIT TO THE RIT KEYING INPUT OF THE VFO.  FOLLOWING THE
‰  END OF 30 WPM TEXT  ‰  QST DE W1AW  ƒ