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3353Re: Sked and rx frequency - help and clarification

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  • Enrico - IZ0GYP
    Nov 18, 2006
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      Paul,

      once again my apologies to you and all the other friends that replied
      to my question.
      I have received and read your mails both on WSJT and direct to my
      private mail.
      Let me just inform you that i had sent my reply and thanks to all of
      you already on November 14th but i did probably an uncorrect
      operation while sending the answer back on the WSJT area.

      Therefore herebelow is the text that i wrote few days ago thanking
      all of you for the kind, prompt and precise support.

      - - - - - - - - - -

      Ok OM,

      thank you very much all of you for the appreciated suggestions.
      Due to the replies and to the emails received on my mail account i
      have understood very well principles, tecniques and i realized that
      my FT-736R would probably require a freq calibration.

      So thanks Jim (AF6O), Lee (AA1YN), John (W5UWB), Paul (G4DCV) and Don
      (KE7NR) for the valid support and CU all via the moon.

      Ciao

      Enrico - IZ0GYP


      - - - - - - - -

      So, once again, thanks and sorry if my post did not came through.

      I will be trying to call starting from tomorrow morning.

      Ciao e grazie

      Enrico



      --- In wsjtgroup@yahoogroups.com, Paul Whatton <paul@...> wrote:
      >
      > Hi Enrico
      >
      > Congratulations on your QRP EME. I'm also using a small station
      which is
      > very similar to yours, a FT736R, 400 watts and a single 9 element
      F9FT.
      > The FT736R is very stable and works really well on WSJT. The FT-
      736R is
      > much stabler than my second rig, an Icom 746.
      >
      > It sounds from what you sayt that your 736 calibration is 700Hz
      out.
      > Mine is about 200Hz out, so I know when my display reads say,
      144.130.2
      > I am actually on 144.130. So just take your 700Hz error into
      account. Or
      > even better if you have the workshop facilities you could re-
      calibrate
      > your display.
      >
      > Having done that you know what frequency you are tuned to, but what
      > about the doppler? On 2m it is only a maximum value of about 300Hz
      and
      > most of the time much less than that if like me you use elevation.
      But
      > it is nice to be close to the correct frequency and the doppler can
      be
      > tricky to get your head around. Having said that, if there is a
      pileup,
      > it's often better to call a bit off frequency!
      >
      > I don't pretend to be an expert and maybe someone will correct me
      if I'm
      > wrong here. But this is what I figured out.
      >
      > If you have a sked then yes you are right, transmit on what you
      know to
      > be the correct frequency and stay there. Then look for your sked
      partner
      > to be shifted by his doppler. You won't need the RIT, his traces
      will
      > just be offset away from the centre frequency in WSJT by the amount
      of
      > his doppler plus/minus any error in his transmit frequency. That's
      fine.
      >
      > BTW. I've noticed that even some big guns are not always exactly on
      the
      > frequency they say they will be :-) If (when) you find your sked
      partner
      > is a long, long way off frequency then you have a dilemma. Should
      you
      > stay where you are or should you move?
      >
      > But how about when you want to answer a CQ?
      >
      > Even with just a single 9 element the majority of QSOs I make are
      by
      > calling someone. Either by tail ending or by answering their CQ
      call.
      > Most are random, I usually don't tell them in N0UK or ON4KST that
      I'm
      > going to call.
      >
      > Here's what I do. Let's say I hear a station calling CQ and when
      WSJT
      > decodes him it indicates I am receiving him with a DF of +300Hz.
      But
      > entering his locator tells me his doppler is actually say, -120Hz.
      So I
      > retune the receiver to a frequency 420Hz higher. I should now get a
      DF
      > of -120HZ on his decoded signal, the same figure as his predicted
      > doppler shift. I then call him on that frequency. If I have it
      figured
      > out correctly this will make my transmit frequency the same as his,
      and
      > my received signal will be close to where he hears his own echos
      (all
      > the stations I work will be able to hear their own echos).
      >
      > As an alternative, if you really want to use the RIT you can dial
      in the
      > amount of the doppler and then aim to receive the other station
      with a
      > DF of 0.
      >
      > I didn't have much time in the EME contest yesterday before I had
      to go
      > out. But I called CQ and two stations called me who were both
      > "off-channel" by about 100Hz more than I would have expected from
      their
      > doppler. So don't worry about it too much, even the big EMEers are
      not
      > always spot on frequency.
      >
      > 73 Paul G4DCV
      >
      > Enrico - IZ0GYP wrote:
      > >
      > > Hi all,
      > >
      > > I'm a novice for EME (QRP with 9 element and 200W) and i'm still
      > > studying the JT65B to be more familiar with the communication
      > > procedures, trying to avoid mistakes and loose of time to the
      stations
      > > that would reply to my skeds.
      > > Up to now i succesfully completed 3 QSOs.
      > >
      > > Anyhow my problem is the following.
      > >
      > > If someone, on the EME chat, state a CQ call on 137 (144.137) this
      > > means that both the calling station and the station that would
      like to
      > > reply to his call shall have the VFO on 137,0 during TX.
      > >
      > > Now, i'm using a FT-736R and i'm almost sure about correctness of
      the
      > > freq calibration.
      > >
      > > Usually a receive CQ station EME calls at SpecJT center when my
      VFO is
      > > approx. 0,7 KHz higher (144.137,7).
      > > Otherwise, leaving the VFO at 137,0 , i will see caller EME
      signals at
      > > the far right side of the SpecJT screen (or even outside).
      > > That's of course due to the Doppler effect but my concern is if
      0,7
      > > KHz is a standard frequency doppler shift on VHF or is a little
      bit
      > > too big?
      > > Due to my QRP conditions i can't receive my own echoes and the
      other
      > > stations will see only light signals on their PCs.
      > > I would like also to be sure at least that i'm not spending time
      > > calling on a wrong frequency where the CQ caller station would
      never
      > > receive me.
      > >
      > > Shall i therefore use the second FT-736 VFO on 0,7 KHz higher
      during
      > > rx (FT-736R does not have independent RIT function)?
      > >
      > > Is my understanding correct that if i will be transmitting on the
      sked
      > > frequency also my EME signals will be "falling" in the center
      part of
      > > SpecJT screen of the other station (i guess that he will be also
      > > listening 0,7 KHz higher)?
      > >
      > > Sorry if the questions may be appear probably confused (or even
      > > terrible) to you but your help will be very appreciated on my
      side.
      > >
      > > Thanks for your kind reply and understandings
      > >
      > > Best 73's de Enrico - IZ0GYP
      > >
      > >
      > > ------------------------------------------------------------------
      ------
      > >
      > > No virus found in this incoming message.
      > > Checked by AVG Free Edition.
      > > Version: 7.5.430 / Virus Database: 268.14.3/531 - Release Date:
      12/11/2006 19:34
      > >
      >
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