40m best at night... but for which side of the QSO??

Discussion in 'Ham Radio Discussions' started by KK6OXP, Feb 14, 2018.

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  1. KK6OXP

    KK6OXP Ham Member QRZ Page

    I'm in California. Let's say it is 10pm, here. I'm trying to work Western Europe. It's 6-7am, there.

    To which side does the night-time 40m propagation benefit??

    Is it better to start trying to work Western Europe (for example) when it is 3-4pm PST, and ~midnight over there?


    Thanks!
    Andrew
     
  2. WZ7U

    WZ7U Subscriber QRZ Page

    Gray line, though our early morning seems more lively for that part of the world. At least into my vertical..
     
  3. W4IOA

    W4IOA Ham Member QRZ Page

    I looked in my log and it seems that a large part of my European contacts on average take place between 18-20:00 zulu when I was in Oregon.
    Of course, they're on all the time during the WW contest
     
  4. KK6OXP

    KK6OXP Ham Member QRZ Page


    Interesting. Glad I asked. I thought staying up late was best, due to the D layer disappearing by then. Meaning, during daylight hours, D layer is present, and absorbs our signals.

    However, according to W4IOA's logs, which I'm sure are plentiful, you're saying most of your EU contact was during 18-20:00 zulu... which is 12pm noon PST! That's both amazing and interesting.

    WZ7U same curiosity with your observation. I guess this D layer thing I read about in all the text studying for my ticket isn't as airtight as I thought. Working DX during reasonable hours sounds much better, anyway!
     
  5. KD9HLC

    KD9HLC Ham Member QRZ Page

  6. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    In this VOACAP prediction for LA to Central Europe (SSB, 100 Watts) 40 M is represented by the green line. Time is UTC.
    index.png
     
    KK6OXP, N2EY, AE7LP and 2 others like this.
  7. KW4GT

    KW4GT Ham Member QRZ Page

    It's interesting how the predicted propagation on 40 peaks around 0700Z and then shortly thereafter falls off to nothing.... I imagine that's when the sun is coming up in Europe.
     
  8. W1VT

    W1VT Ham Member QRZ Page

    Which peak is best often depends on your station. A big station may work best when there are a lot of Europeans to work. A smaller station may work better when there is less competition, such as the wee hours of the morning. A fabulous band opening may do you no good if for every European you may be able to work, there are a dozen stateside stations who are louder than you in the pileup.

    Zak W1VT
     
    WZ7U likes this.
  9. WF4W

    WF4W Ham Member QRZ Page

    yes, greyline makes a difference but it's not always black and white - here in GA, yesterday & day before I heard europeans on 40m at 4pm, a few hours before dusk. . . and sometimes, I hear europeans on 20m at 9om when it should be dead :)
     
  10. WU8Y

    WU8Y Ham Member QRZ Page

    Note that, according to timeanddate.com, 18:00 Z on 14 Feb is the beginning of sunset in EU, with only Portugal and Gibraltar still outside of twilight. By 20:00 Z, the twilight line has moved to west of Greenland and down the mid-Atlantic Ocean. So, while the D-layer might be strong over Oregon, it's falling apart over EU at 18:00 and is probably gone altogether by 20:00.

    Consider, also, the take-off angle component of the problem - one-hop signals from Oregon to EU are at a fairly low elevation angle...

    https://www.timeanddate.com/worldcl...8&hour=20&min=0&sec=0&n=1440&ntxt=UTC&earth=0
     
    WZ7U likes this.

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