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How I improved 2m reception and achieved some success on EME

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  • billdz.geo
    Thanks much to everyone who responded (publicly and privately) to my post last month about how to improve 2 meter reception for meteors and EME. People were
    Message 1 of 2 , Jan 6, 2008
      Thanks much to everyone who responded (publicly and privately) to my
      post last month about how to improve 2 meter reception for meteors and
      EME. People were hearing me but I could not hear them. Several
      people wrote and said, "I have the same problem, please let me know if
      you solve it."

      Thanks to several suggestions from this group, my reception has
      substantially improved, and in 2 weeks I have managed 14 contacts on
      EME with a single 2M9SSB antenna and 500w.

      Opinions on a mast-mount preamp were split. Several said it would be
      a big help, others said that I didn't need it, since my coax run is
      just 50' of LMR-400. I bought an SSB SP-2000 and put it on the mast
      and it seems to have helped quite a lot. John W5UWB noted that, even
      with a short coax run, the signal gets attenuated in the power
      amplifier relay contacts.

      Several folks noted that local noise could be the problem, and Paul
      G4DCV had the great suggestion of making a cheap manual elevation
      rotator with a pair of angle brackets. Cost about $10. Several
      people had said that my best chance to work EME would be at moonrise
      and moonset with no antenna elevation, because of the "extra 6 db
      ground gain" during these times. However, I've had much better
      success with the moon high off the ground, 60 degrees or higher with
      the moon on the rise. It seems the lack of ground gain at elevation
      is more than offset by the lower noise. The receiver is just a lot
      quieter when the antenna is pointed in the air rather than along the
      ground.

      Another important factor is antenna polarity. Some said polarity was
      irrelevant for EME due to Faraday. However, my limited experience
      indicates this is incorrect. There appears to be a benefit to having
      your signal arrive at the same spatial polarity as the other station's
      antenna. Spatial polarity is shown on W5UN's Skymoon and other
      software. Most of the time, there is close to a 90 degree spatial
      polarity difference between the USA and Europe (the location of most
      of the bigger stations my single yagi can hear). As most EMEers are
      horizontally polarized, this means that a USA station is better off
      going vertical to work the Europeans. This may become less of an
      issue as the XP switchable polarity antennas become more popular.

      In terms of operating practice, not sure everyone would agree with
      this, but I do not call CQ or make schedules on the reflector. This
      is because I don't want to waste people's time, and I still can't hear
      most stations. A station with 4 stack of antennas and a kilowatt
      seems to be about the smallest I can work (fortunately, this is a
      quite popular combination). So I watch the chris.org reflector and
      see where the bigger stations are calling CQ, and if I hear someone
      I'll just answer the CQ or perhaps say on the reflector something
      like, "W1XXX, I'm calling you." Most folks on the reflector
      thoughtfully give their antenna and power after the call (e.g.,
      "W1XXX/2x12/800"), and I wish everyone would do so, because it lets
      you know if you have any hope of working him.

      The bigger stations have worked almost everyone available and often
      CQ for a long time without any answer. You can use them sort of as a
      beacon to tune your system and to see how often the antenna needs to
      be moved. Some say an adjustment once an hour is sufficient, but it's
      no bother to move mine manually and I think it helps to re-spot the
      antenna on the moon every 15 minutes or so. One evening K9MRI was
      coming in strong and clear, so I moved the antenna to the spot where
      it would be on the moon in an hour. I left the radio on Joe's
      frequency and just waited and watched as CQ K9MRI appeared, got louder
      and louder, and then slowly weakened and diappeared about 30 minutes
      after it had peaked.

      I had thought that with my set-up I would only be able to work W5UN
      and a couple of other super-stations, and it's been a pleasant
      surprise to be able to work more. EME is really fun, wish I had room
      for a bigger antenna system. Not sure if what worked for me will work
      for you, but it's worth a try. Again, thanks to all who helped me get
      started.

      73, Bill NZ5N
    • Les Listwa
      As a relative new comer to EME, I would like to second Bill s wish that everyone on the reflector would follow the format of providing their antenna and
      Message 2 of 2 , Jan 7, 2008
        As a relative new comer to EME, I would like to second Bill's wish that
        everyone on the reflector would follow the format of providing their
        antenna and power after the call (e.g., "W1XXX/2x12/800") as it give us a
        better idea of what we are dealing with; be it QRP or a big gun or something
        in between.
        73s Les - WB2SZR & Daniel- W2DBL
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