‰  NOW 25 WPM  ‰  TEXT IS FROM SEPTEMBER 2018  QST  PAGE 53 ‰

LINE.  IF THE SWR IS GREATER THAN 1 1, THE VOLTAGE AND CURRENT WILL VARY
ALONG THE LINE WITH THE HIGH CURRENT POINTS ALSO BEING THE LOW VOLTAGE
POINTS, AND VICE VERSA.  IN SOLID STATE AMPLIFIERS, THE OUTPUT IS GENERALLY
DIRECTLY CONNECTED TO THE ACTIVE DEVICE THROUGH A FILTER WITH THE RESULT
THAT A LOW IMPEDANCE OR HIGH CURRENT LOAD WILL DRAW A HIGHER THAN RATED
CURRENT THROUGH THE OUTPUT TRANSISTORS.  SIMILARLY, IF THE VOLTAGE IS HIGH
AT THE OUTPUT CIRCUIT, COMPONENTS MAY BREAK DOWN AS A RESULT OF THE HIGHER
THAN RATED VOLTAGE.  VACUUM TUBE AMPLIFIERS GENERALLY HAVE A COUPLING
CIRCUIT AT THE OUTPUT, BETWEEN THE TUBES AND THE ANTENNA.  IN RECENT MODELS
C. LATE 1950S AND LATER, IT IS OFTEN AN ADJUSTABLE PI NETWORK, WHICH CAN
MATCH A RANGE OF IMPEDANCES, BUT IS USUALLY CENTERED AROUND 50.  IF THE SWR
IS HIGH, THE IMPEDANCE WONT BE NEAR ENOUGH TO 50 TO BE MATCHED.  IF IT IS
BEYOND THE MATCHING RANGE OF THE PI NETWORK, THE PLATE CURRENT WILL EITHER
‰  END OF 25 WPM TEXT  ‰  QST DE W1AW  ƒ