=  NOW 30 WPM  =  TEXT IS FROM MAY 2024 QST  PAGE 36 =

STATIONS, HIGHER TOAS ARE MORE USEFUL. WHEN USING A STACKED ARRAY, YOU CAN
MAINTAIN COMMUNICATION OVER THE DESIRED PATH BECAUSE YOU CAN INSTANTANEOUSLY
CHANGE THE TOA.  YOU CAN SELECT COMBINATIONS OF STACKED ANTENNAS, OR A
SINGLE ANTENNA, TO PUT THE DX STATION IN THE MAIN LOBE OF THE ANTENNA
INSTEAD OF A DEEP NULL. ALTERNATIVELY, YOU CAN DROP A STRONG, INTERFERING
STATION INTO THE NULL OF THE ANTENNA PATTERN SO THAT YOU CAN COPY THE
DESIRED SIGNAL.  YOU CAN ALSO MOVE THE MAIN LOBE AND NULLS BY FEEDING SOME
OF THE ANTENNAS OUT OF PHASE. WITH ITS DIFFERENT TOAS, A STACKED ARRAY IS
HELPFUL FOR MAINTAINING CONTACT DURING CHANGING AND MARGINAL BAND
CONDITIONS.  DURING A DX BAND OPENING, THE INITIAL SIGNALS USUALLY APPEAR AT
LOW ELEVATION ANGLES.  AS THE BAND STRENGTHENS AND SPREADS, SIGNALS AT
HIGHER ELEVATION ANGLES ARE THE STRONGEST.  AS THE BAND CLOSES, SIGNALS AT
LOW ANGLES WILL AGAIN BE THE STRONGEST.  BECAUSE A STACKED ARRAY ALLOWS FOR
DIFFERENT TOAS AND ADDITIONAL GAIN, IT STRETCHES THE BAND OPENING.  YOU CAN
SOMETIMES CONTACT DX STATIONS BEFORE OTHER LOCAL STATIONS CAN HEAR THEM, IN
ADDITION TO WORKING THEM LONG AFTER OTHER LOCAL STATIONS LOSE PROPAGATION.
=  END OF 30 WPM TEXT  =  QST DE W1AW  <