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From: G0MRF@aol.com
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Date: Thu, 13 Sep 2007 21:50:28 EDT
To: rsgb_lf_group@blacksheep.org
MIME-Version: 1.0
Subject: Re: LF: 500 QSB
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Hi John / LF
 
That's a very interesting comment.  Not because of the 2-3 minute  period 
that you have observed, but because you think it's unusual.
 
Having monitored my beacon for a fair time now I've noticed that after  
sunset the typical period for a cycle of QSB seems to be 3 minutes. That's at a  
range of 150km and 700km (thanks to Dave 'YXM and Hartmut)
 
I'm intrigued as to the conditions you normally experience with Finbar at  
22.00 local over a sea path. Is that consistent propagation or do you have less  
destructive QSB over a shorter or longer period?
 
I notice in this months Rad Com, which fell through the door today, That  Pat 
Hawker devotes a couple of pages to 500kHz. While suitcase transmitters  are 
thankfully absent, he does quote extensively from a recent QEX article which  
makes some interesting observations about short vertical vs loop antennas and  
how 500kHz can produce optimal ground wave in terms of S:N per Watt over 60  
to 200 miles.
 
Sadly, he also says that as yet, he hasn't heard a single UK station on  500k 
yet.
 
Still, all publicity is good publicity.
 
73
 
David

 
Hello LF Group,

Finbar and I moved our sked forward tonight to  9pm local (20:00UTC) and
noticed some rather rapid, deep fading. I'm not  sure if this was time
related due to being closer to our sunset time, or  condition related.
I'm sure the fading is generally slower and less  catastrophic in the
dips.

The QSB on Finbar's signal went from RST  579 to NIL and back over a
period of around 2-3 minutes.

Some  periods were much shorter, some longer, but in the 20 minute QSO
there must  have been 5 or 6 complete cycles. The QRN made it a bit
difficult to tell  if the signal was fading or the noise increasing  at
times!


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<DIV>
<DIV>Hi John / LF</DIV>
<DIV>&nbsp;</DIV>
<DIV>That's a very interesting comment.&nbsp; Not because of the 2-3 minute=20
period that you have observed, but because you think it's unusual.</DIV>
<DIV>&nbsp;</DIV>
<DIV>Having monitored my beacon for a fair time now I've noticed that after=20
sunset the typical period for a cycle of QSB seems to be 3 minutes. That's a=
t a=20
range of 150km and 700km (thanks to Dave 'YXM and Hartmut)</DIV>
<DIV>&nbsp;</DIV>
<DIV>I'm intrigued as to the conditions you normally experience with Finbar=20=
at=20
22.00 local over a sea path. Is that consistent propagation or do you have l=
ess=20
destructive QSB over a shorter or longer period?</DIV>
<DIV>&nbsp;</DIV>
<DIV>I notice in this months Rad Com, which fell through the door today, Tha=
t=20
Pat Hawker devotes a couple of&nbsp;pages to 500kHz. While suitcase transmit=
ters=20
are thankfully absent, he does quote extensively from a recent QEX article w=
hich=20
makes some interesting observations about short vertical vs loop antennas an=
d=20
how 500kHz can produce optimal ground wave in terms of S:N per Watt&nbsp;ove=
r 60=20
to 200 miles.</DIV>
<DIV>&nbsp;</DIV>
<DIV>Sadly, he also says that as yet, he hasn't heard a single UK station on=
=20
500k yet.</DIV>
<DIV>&nbsp;</DIV>
<DIV>Still, all publicity is good publicity.</DIV>
<DIV>&nbsp;</DIV>
<DIV>73</DIV>
<DIV>&nbsp;</DIV>
<DIV>David</DIV>
<BLOCKQUOTE style=3D"PADDING-LEFT: 0px; MARGIN-LEFT: 0px">
  <DIV><FONT style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#0=
00000=20
  size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#0=
00000=20
  size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#0=
00000=20
  size=3D2>Hello LF Group,<BR><BR>Finbar and I moved our sked forward tonigh=
t to=20
  9pm local (20:00UTC) and<BR>noticed some rather rapid, deep fading. I'm no=
t=20
  sure if this was time<BR>related due to being closer to our sunset time, o=
r=20
  condition related.<BR>I'm sure the fading is generally slower and less=20
  catastrophic in the<BR>dips.<BR><BR>The QSB on Finbar's signal went from R=
ST=20
  579 to NIL and back over a<BR>period of around 2-3 minutes.<BR><BR>Some=20
  periods were much shorter, some longer, but in the 20 minute QSO<BR>there=20=
must=20
  have been 5 or 6 complete cycles. The QRN made it a bit<BR>difficult to te=
ll=20
  if the signal was fading or the noise increasing=20
at<BR>times!<BR></DIV></FONT></BLOCKQUOTE></DIV>
<DIV></DIV>
<DIV>&nbsp;</DIV></FONT>   </BODY></HTML>

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