‰  NOW 13 WPM  ‰ TEXT IS FROM MARCH 2009 QST  PAGES 42 AND 79  ‰

LOWER DISTORTION IN CHANNEL, SO THEY SOUND VERY GOOD, BUT FILTER RIGS HAVE
FEWER OFF CHANNEL SPURIOUS OUTPUTS.  CHECKING IT TWICE THE PROCEDURE I USE
FOR A QUICK CHECK OF AMPLIFIER PERFORMANCE BEFORE PUTTING A SIGNAL ON THE
AIR IS VERY DIFFERENT FROM THE MEASUREMENTS AND EXPERIMENTS I USE TO DESIGN
AN AMPLIFIER.  WITH THESE AMPLIFIERS, I CONNECT A DUMMY LOAD AND WATTMETER
TO THE OUTPUT OF THE LOW PASS FILTER, AND DRIVE THE AMPLIFIER CHAIN TO
SATURATION WITH A CW SIGNAL.  I OBSERVE THE CURRENT DRAIN AT THIS SATURATED
ƒ  QST DE W1AW  ‰
OUTPUT LEVEL, AND THEN SET THE RESTING BIAS TO ABOUT ONE TENTH THAT LEVEL.
THESE 5 W AMPLIFIERS IDLE AT AROUND 100 MA, SO THAT IS 1R8 W FOR THE 7 MHZ
AMPLIFIER AND 2R7 W FOR THE 6 METER VERSION.  THEN I SPEAK INTO THE
MICROPHONE AND OBSERVE THAT THE OUTPUT PEAKS ARE ABOUT 3 DB BELOW THE
‰  FROM PAGE 79  ‰
81,134 VE7SZ 736,101 RX1CQ 214, 800 KH7B 1,671,502 NT4XT 22,797 K0RH 388,
803 OM7DX 201,630 4L0A 1,577, 532 N0LY 22,144 W2RDS 286,625 RW3AI 192,736
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