=  NOW 40 WPM  =  
HE IS ACTIVE ON 40 AND 20 METER SSB, USING HOMEBREW TRANSCEIVERS.
YOU CAN CONTACT JIM AT JFORKIN VERIZON. NET.  CONGRATULATIONS MAY
2021 QST COVER PLAQUE AWARD WINNER FRANK DONOVAN W3LPL IN HIS
ARTICLE, WHAT TO EXPECT DURING THE RISING YEARS OF SOLAR CYCLE 25,
FRANK SHARES SOME PREDICTIONS ON HOW HF PROPAGATION MAY BE AFFECTED
IN THE NEXT 4 YEARS.  QST COVER PLAQUE AWARDS ARE GIVEN TO THE
AUTHOR OR AUTHORS OF THE MOST POPULAR ARTICLE IN EACH ISSUE.  YOU
CHOOSE THE WINNERS BY C THIS CIRCUIT IS ALSO USEFUL WITH OTHER HOME
BUILT RECEIVERS.  JAMES FORKIN, WA3TFS MY SIMPLE HIGH FREQUENCY
COMMUNICATIONS RECEIVER SEE THE LEAD PHOTO, WHICH WAS FEATURED IN
THE MAY 2020 ISSUE OF QST, HAS MANUAL GAIN CONTROLS THAT MUST BE
ADJUSTED WHEN THE SIGNAL LEVELS ARE OF VARYING SIGNAL STRENGTH.  AN
AUTOMATIC GAIN CONTROL AGC CIRCUIT WOULD KEEP THE AUDIO OUTPUT AT A
MORE CONSISTENT LEVEL ON WEAK SIGNALS AND ATTENUATE THE AUDIO WHEN
THE INCOMING SIGNAL IS AT A MUCH HIGHER LEVEL, THEREBY ELIMINATING
THE NEED TO READJUST GAIN MANUALLY.  THIS SIMPLE AGC CIRCUIT MEETS
THAT NEED.  THE CIRCUIT RETAINS THE MANUAL GAIN CONTROL FUNCTION,
AND ALSO PROVIDES AN OUTPUT TO DRIVE AN S METER.  TWO DIFFERENT AGC
OUTPUTS ARE PROVIDED.  ONE INCREASES LEVEL WHEN A LOUD SIGNAL IS
RECEIVED, AND A SECOND ONE DECREASES LEVEL ON A LOUD SIGNAL.  THE
SECOND OUTPUT IS USED WITH MY SIMPLE HIGH FREQUENCY COMMUNICATIONS
RECEIVER.  THE CIRCUIT THE DESIGN SEE FIGURE 1 USES A HANDFUL OF
READILY AVAILABLE AND INEXPENSIVE THROUGH HOLE PARTS.  A 1R35 X 2R45
INCH PCB IS AVAILABLE AT.  YOU COULD ALSO WIRE IT ON PERF BOARD MY
BOARD LAYOUT IS ON THE QST IN DEPTH WEB PAGE AT ARRL. ORG/QST IN
DEPTH.  PROVIDE A GOOD GROUND PLANE FOR BEST PERFORMANCE.  THREE
POTENTIOMETERS ALLOW FULL ADJUSTMENT OF AGC ACTION.  ONE IS USED TO
SET THE POINT AT WHICH AGC ACTION IS DESIRED.  A SECOND PROVIDES
ADJUSTMENT TO CALIBRATE AN OPTIONAL S METER, AND A THIRD SETS THE
LEVEL OF ATTENUATION WHEN A STRONG SIGNAL IS PRESENT.  THE INPUT TO
THE AGC CIRCUIT CONNECTS TO THE TOP OF THE EXISTING RECEIVER VOLUME
CONTROL, WHICH IS THE OUTPUT FROM THE AUDIO PREAMP.  POTENTIOMETER
R8 SETS THE THRESHOLD POINT WHERE AGC ACTION BEGINS.  THE SIGNAL IS
AMPLIFIED BY Q1 AND RECTIFIED BY D1 AND D2.  THE RECTIFIED SIGNAL
CHARGES C6.  THE DC VOLTAGE LEVEL STORED ON C6 VARIES WITH THE
INCOMING AUDIO LEVEL.  IT IS THEN AMPLIFIED BY Q2 AND, IF DESIRED,
OPTIONALLY DRIVES THE POSITIVE INPUT OF A 1 MA FULLSCALE S METER.
THE NEGATIVE S METER LEAD CONNECTS TO GROUND.  POTENTIOMETER R9
ADJUSTS THE LEVEL TO CALIBRATE THE METER.  THE AMPLIFIED SIGNAL ALSO
PASSES TO Q3, WHICH IS CONNECTED TO THE RECEIVER BOARD AT R8 OF
FIGURE 2.  AS SIGNAL LEVEL INCREASES, Q3 BEGINS TO TURN ON.  AS
INPUT SIGNAL LEVEL INCREASES, THE AGC BOARD DRAWS MORE CURRENT.
LESS CURRENT FLOWS THROUGH D2 OF FIGURE 2 ON THE RECEIVER BOARD, SO
GAIN DECREASES IN THE SECOND IF AMPLIFIER STAGE AND THAT, IN TURN,
LESSENS THE DETECTED AUDIO LEVEL.  YOU MUST MODIFY THE RECEIVER, AS
SHOWN IN FIGURE 2.  LIFT ONE END OF THE R8 RESISTOR AND INSERT
=  END OF 40 WPM TEXT  =  QST DE W1AW  <