‰  NOW 40 WPM  ‰  TEXT IS FROM DECEMBER 2005 QST  PAGES 32, 34 AND 97  ‰

THE ARTICLE, BUT DO NOT MOUNT THE INPUT CONNECTOR.  THE TOP BOARD IN FIGURE
2 SHOWS A PARTLY ASSEMBLED PICK UP BOARD.  LOOK AT THE TERMINAL STRIP UPPER
RIGHT.  THE TERMINAL STRIP REPLACES THE INPUT CONNECTOR J1.  IT IS USED TO
SUPPORT C10 AND THE INPUT END OF THE COA
‰  FROM PAGE 97  ‰
Metropolitan ARC K8NOW 309 2 8 918 MI KIOLA 34 2 12 918 CO Nevada ARC N0IY

THE RF POWER TRANSISTORS COOL DURING TYPICAL USE.  WITH 5 W INPUT, THE
OUTPUT CAN BE AS HIGH AS 100 W.  THE AMPLIFIER IS NOT INTENDED FOR 100 DUTY
CYCLE OPERATION, BUT WOULD TOLERATE THE EXTRA HEAT WITH AN ADDED FAN.  RF
COMING INTO THE SUPERPACKER GOES DIRECTLY TO THE CONTROL BOARD.  THE
CONTROL BOARD HAS A VERY SENSITIVE VOX CIRCUIT.  THE VOX CIRCUIT ACTIVATES
TR SWITCHING RELAYS ON THE RELAY BOARD AT THE START OF TRANSMISSION.  YOU
CAN, HOWEVER, USE THE PUSH TO TALK PTT INPUT INSTEAD.  JUST GROUND THE PTT
INPUT TO TRANSMIT.  THE PTT LINE DRAWS ABOUT 20 MA OF CURRENT.  PTT CONTROL
OF THE AMPLIFIER SPEEDS UP TR SWITCHING AND IS IDEALLY SUITED FOR CONTEST
OPERATION.  A JUMPER JP1 ON THE CONTROL BOARD CAN BE USED WITH PTT
OPERATION TO ELIMINATE THE VOX DELAY.  IN ADDITION TO DRIVING THE VOX
CIRCUITRY, THE INPUT RF PASSES THROUGH AN ATTENUATOR FORMED BY R5 THROUGH
R7 ON THE CONTROL BOARD.  ALMOST ANY QRP RIG CAN BE CONNECTED TO THE INPUT
S LONG AS ATTENUATOR R5 TO R7 IS SET TO PROVIDE A MAXIMUM OF 2R5 W OUTPUT
FROM THE ATTENUATOR.  THE VALUES SHOWN ON THE SCHEMATIC PROVIDE 3 DB OF
ATTENUATION, WHICH IS SUITABLE FOR A 5 W TRANSCEIVER LIKE THE YAESU FT 817.
‰  FROM PAGE 97  ‰
W0CUO 164 2 11 1,122 NE Lee DeForest ARC W6OB 209 2 10 1,084 ORG Tri Co ARC
VE9EWR 154 2 14 1,082 MAR Disney Emergency ARS WD4WDW 162 2 4 1,074 NFL
Morgan Co R L School Club KC0LZD N0AYI 69 2 35 1,056 MO C 5 KI7EL 200 2 3
‰  QST DE W1AW  ƒ

BOTH THE ATTENUATOR AND VOX CIRCUITRY ARE TAKEN DIRECTLY FROM K5OORS HF
PACKER AMPLIFIER PROJECT, WHICH IS A REFINEMENT OF THE 2001 ARRL HANDBOOK
DESIGN BY WA2EBY.  SEE K5OORS WEB SITE WWW. HFPROJECTS. COM FOR DETAILS.
IN ADDITION TO THE RF INPUT CIRCUITRY, THE CONTROL BOARD HAS A POWER FUSE,
AND THE DC AMPLIFIER FOR POWER CUTBACK.  WHEN THE PIC SWR METER DETECTS A
HIGH SWR CONDITION, IT DRIVES THE BASE OF Q4 THROUGH R9.  Q3 AND Q4 FORM A
DARLINGTON PAIR AMPLIFIER FOR ACTIVATING RELAY RY2 ON THE RELAY BOARD.  RY2
ADDS R8 THROUGH R10, ANOTHER P SECTION ATTENUATOR, IN SERIES WITH THE POWER
AMPLIFIER BOARDS INPUT.  R8 THROUGH R10 INTRODUCE 10 DB OF ATTENUATION,
CORRESPONDING TO A 10 1 REDUCTION IN DRIVE POWER.  THESE RESISTOR VALUES
ARE FIXED AND DO NOT DEPEND UPON THE TRANSCEIVER BEING USED.  LOOKING AT
THE CONTROL BOARD AGAIN, WHEN Q3 ACTIVATES THE RELAY FOR POWER CUTBACK IT
ALSO LIGHTS UP THE GREEN LED CIRCUIT.  Q2 ACTS AS AN INVERTER AND LIGHTS
THE RED LED WHEN Q3 IS OFF NO POWER CUTBACK.  THE GREEN AND RED LEDS CAN BE
‰  FROM PAGE 97  ‰
1,044 WWA Amateur Radio Transmitting Society W4CN 229 2 17 1,032 KY Lemhi
ARC AD7AN 158 2 4 1,032 ID Calaveras ARS WA6YGA 186 2 6 1,008 SJV Six Meter
‰  END OF 40 WPM TEXT  ‰  QST DE W1AW  ƒ