Loading ...
Sorry, an error occurred while loading the content.

Re: [dxatlas] Newbie questions (tons of them)

Expand Messages
  • digitaleli
    Man you are so helpful! Thanks soooo much for the quick reply and answers to my questions! Not only are you a GREAT programmer, but your very quick to answer
    Message 1 of 2 , Apr 28, 2004
    • 0 Attachment
      Man you are so helpful! Thanks soooo much for the quick reply and
      answers to my questions! Not only are you a GREAT programmer, but
      your very quick to answer any posts or patch any issues. I am glad I
      purchased DX Atlas and am eagerly looking forward to any other
      software you will release. Cheers!

      73,
      KC0RDG

      --- In dxatlas_group@yahoogroups.com, "Alex, VE3NEA" <alshovk@d...>
      wrote:
      > Hello,
      >
      >
      > > 1) What do the light and dark areas mean on the map? Does dark
      mean
      > > that that area on the map is a dead zone? Or does it mean
      ionization
      > > is highest there and thus the best chance of contacting a station?
      >
      > If you are talking about the HamCap SNR map, then brighter areas
      correspond
      > to higher SNR.
      >
      >
      >
      > > 2) What does SNR mean? What is SNR? Why do I need to know this?
      > > How does it affect QSO's?
      >
      > SNR is Signal-to-Noise Ratio.
      >
      > Three factors affect the availability of the path: 1) MUF. If the
      MUF is
      > below the operating frequency, the path is closed, no matter how
      much power
      > you put in the antenna; 2) path losses. Signal absorption along the
      path can
      > result in a closed path even if the MUF is high enough; 3) noise
      level. Even
      > if the MUF is right and the signal is strong, the path still may be
      closed
      > if the noise in the recipient's area is stronger than your strong
      signal.
      > You can estimate these 3 parameters separately to see if the path
      is open or
      > not, but it is more convenient to just check the predicted SNR, as
      this
      > parameter takes into account all three factors. If the SNR is 3 dB
      or
      > higher, your chances are good.
      >
      >
      >
      > > 3) When I move my cursor around the map in DXAtlas, I see the MUF
      > > change in HamCAP. Is that the MUF for me trying to reach that
      > > location (the location where my cursor is)? Or would I put the
      > > cursor over my QTH and go off what it is telling me the MUF is?
      >
      > The MUF and other parameters displayed on the status bar in HamCap
      are for
      > the path that starts at your home QTH and ends at the point under
      the
      > cursor.
      >
      >
      >
      > > 4) The MUF is the maximum (ie. highest) frequency that, based on
      the
      > > SSN, etc, is best to reach the station?
      >
      > Usually the best frequency is about 80% below MUF, but there are
      exceptions.
      > See my answer to question 2.
      >
      >
      >
      > > 5) The critical frequency is the highest frequency you can use
      before
      > > the radio waves start going through the ionosphere?
      >
      > Yes
      >
      >
      >
      > > 6) How do critical frequency and MUF differ then?
      >
      > Critical frequency is just the MUF of a vertical path.
      >
      >
      >
      >
      > > 7) From what I understand, you would find a place you would like
      to
      > > work, then find out the MUF and stay below that and the Crit Freq?
      >
      > No. You would select the frequency with highest SNR.
      >
      >
      >
      > > 8) When I have the 3 apps open at once, there is a little yellow
      sun-
      > > like icon down on the bottom of DXAtlas that displays a number
      like
      > > 8:33-21:15. What does this mean?
      >
      > This is the sunrise and sunset time for the point under the mouse
      cursor.
      >
      >
      >
      > 73 Alex VE3NEA
    Your message has been successfully submitted and would be delivered to recipients shortly.