‰  NOW 40 WPM  ‰  TEXT IS FROM AUGUST 2012 QST  PAGE 54‰
MATCHED.  THUS THE VOLTAGE CAN EASILY BE 5 TO 10 TIMES HIGHER THAN AN
ARRESTOR WOULD EXPECT, MEANING THAT THE ARRESTORS COULD FIRE IN NORMAL
OPERATION, A SERIOUS POTENTIAL PROBLEM FOR THE TRANSMITTER.  WHILE THE HIGH
VOLTAGE WILL EXIST SOMEWHERE ON THE MISMATCHED TRANSMISSION LINE, NOT
NECESSARILY AT THE ARRESTOR, WITH THE USUAL MULTIBAND APPLICATION, THERE IS
A GOOD CHANCE THAT THE HIGH VOLTAGE WILL BE NEAR THE ARRESTOR ON AT LEAST
ONE BAND.  TO BE SAFE, CHECK WITH THE MA

PATTERN.  I HAVE A QUESTION ABOUT WORKING THE LOW EARTH ORBIT LEO FM
SATELLITES.  I USE A HANDHELD 2 METER AND 70 CM YAGI ANTENNA AND SOMETIMES
HAVE A HARD TIME MAKING IT INTO THE BIRD.  I TWIST THE ANTENNA TO MATCH THE
POLARIZATION OF THE SIGNAL ON 2 METERS.  I THEN MAINTAIN THIS CONFIGURATION
FOR THE DURATION OF THE PASS, DEVIATING SLIGHTLY TO COMPENSATE FOR THE
TUMBLING OF THE BIRD.  ON MY ANTENNA, THE 2 METER AND 70 CM YAGIS ARE OF
OPPOSITE POLARIZATIONS.  THERE IS ANOTHER ANTENNA IN WHICH THE TWO BANDS
ARE BOTH OF THE SAME POLARIZATION.  I WONDER IF THE TWO ANTENNAS ON THE
SATELLITE ARE OF THE SAME POLARIZATION, OR ARE THEY ORTHOGONAL AS WELL?  IF
THEY ARE OF THE SAME POLARIZATION, SHOULD I BE TWISTING MY ANTENNA 90 BY
HAND BETWEEN MY RECEIVING AND TRANSMITTING TIMES.  WHAT OTHER OPTIONS ARE
FEASIBLE?  I DONT HAVE EXPERIENCE WORKING THROUGH LEOS, SO ASKED QST EDITOR
STEVE FORD, WB8IMY, WHO PROVIDED THE FOLLOWING BECAUSE HAM SATELLITES ARE
USUALLY NOT STABILIZED, THEY ARE FOREVER TUMBLING AND CHANGING THEIR
ANTENNA ORIENTATIONS.  THATS WHY SOME RECOMMEND CIRCULARLY POLARIZED GROUND
STATION ANTENNAS BETTER TO HEDGE ONES BETS, SO TO SPEAK.  THERE IS AN

THE DOCTOR IS IN JOEL R. HALLAS, W1ZR, W1ZR ARRL. ORG  SIMPLE MAY BE IN THE
EYE OF THE BEHOLDER  WHAT ARE THE RELATIVE BENEFITS OF A MULTIBAND VERTICAL
ANTENNA WITH VARIOUS TUNED SECTIONS OR OTHER RESONANT ARRANGEMENTS,
COMPARED TO A SIMPLE 43 FOOT VERTICAL WITH AN ANTENNA TUNER?  THE ADVANTAGE
OF A TRAP, OR OTHER MULTIBAND VERTICAL, IS THAT THEY ARE DESIGNED TO
PROVIDE A DIRECT MATCH TO 50 COAX WITHOUT THE NEED FOR A TUNER, ALTHOUGH
PARTICULARLY ON THE LOWER FREQUENCY BANDS, THEY WILL BE UNLIKELY TO COVER
EACH COMPLETE BAND WITHOUT USE OF A TUNER.  THE 43 FOOTER, TO OPERATE ON
DIFFERENT BANDS WILL NEED A MATCHING NETWORK AT THE BASE TO OPERATE
EFFICIENTLY DEPENDING ON POWER, PERHAPS MAKING THE TOTAL COST SIMILAR.  IN
MANY CASES, IT WILL BE MORE INVOLVED THAN JUST AN AUTO TUNER, SINCE THE
TUNING RANGE OF THE TUNER MAY NOT BE WIDE ENOUGH TO COVER 160 METERS.  IN
TERMS OF RADIATING PERFORMANCE, THE MULTIBAND VERTICAL WILL HAVE A PATTERN
LOOKING ABOUT LIKE A 1/4 OR 1/2 WAVE ANTENNA DEPENDING ON DESIGN.  THE HALF
WAVE TYPES HAVE THE ADVANTAGE OF NOT REQUIRING A LARGE RADIAL FIELD OR
GROUND SYSTEM FOR EFFICIENT OPERATION.  THE 43 FOOTER WITH A GOOD GROUND
SYSTEM WILL GENERALLY PROVIDE 1 OR 2 DB HIGHER GAIN ON 160 THROUGH 20
METERS THAN THE MULTIBAND VERTICAL, WHILE THE MULTIBAND, MAY BE SLIGHTLY
BETTER ON THE HIGHER FREQUENCY BANDS, BUT WILL CERTAINLY HAVE A BETTER
‰  END OF 40 WPM TEXT  ‰  QST DE W1AW  ƒ