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Great Bulletin thanks
Bob AD5VJ
> -----Original Message-----
> From: propagation-bounces@contesting.com
> [mailto:propagation-bounces@contesting.com] On Behalf Of
> Thomas Giella KN4LF
> Sent: Saturday, February 16, 2008 9:27 AM
> To: a COL Propagation; a Propagation Forecast; a DXLD eGroup
> Subject: [Propagation] Poor 160 Propagation at Solar Minimum
>
> This e-mail posting is from the Radio Propagation Reflector
> that you're currently subscribed to. Refer to the end of
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>
> Borrowed from Glenn Hauser's DX LISTENING DIGEST 8-020,
> February 15, 2008.
>
> PROPAGATION
> +++++++++++
>
> 160 METER MYTHS
>
> Ed Swynar, VE3CUI, of Newcastle, Ontario, took issue with a
> statement in last week's bulletin about the absence of
> sunspots being great for 160 meters. "Such mythology could
> not be further from the truth this year. The band has been
> most unremarkable this season, to say the least, and it
> continues to languish away in the doldrums. I thought that
> perhaps it was something at fault at my end: however, many
> subscribers to W4ZV's Topband Reflector seem to be of the
> same opinion." Readers have sent similar reports about both
> 160 and 75 meters over the past year. It seems that low
> geomagnetic and sunspot activity should be good for the lower
> frequencies, but perhaps it is not always the case.
>
>
> On my website KN4LF 160 Meter Radio Propagation Theory Notes:
> http://www.kn4lf.com/kn4lf8.htm under:
>
> 5.) Coronal Hole-
>
> .....Coronal Holes occur most often on the downside of a
> solar cycle and their absence at the bottom of a solar cycle
> and at the beginning of the next, allow for the best medium
> frequency radio propagation conditions. Many think it's the
> lower solar flux values seen at the bottom of a solar cycle
> that accounts for improved propagation conditions but it's
> actually pretty much a lack of Coronal Holes and geomagnetic
> storming. (See definition #11.
> Geomagnetic/Ionospheric Storm).....
>
> 3.) Equatorial Ring Current-
> .....A phenomena that acts as a repository for precipitated
> electrons in the vicinity of the magnetic equator. The
> electrons travel by spiraling around north south magnetic
> field lines at a frequency called the 'gyro frequency.
> The end result is lower latitude propagation path medium
> frequency transmitted RF signal blockage and absorption via
> the D layer. Absorption is similar to higher latitude Aurora
> Oval absorption and is inter-related with same.....
>
> 2.) Aurora Oval Blockage, Absorption And Refraction-
>
> .....The aurora ovals "generally" have a negative impact on
> medium frequency propagation. If the path over which you are
> communicating lies along or inside one of the Aurora Ovals,
> you will experience degraded propagation in one of several
> forms; strong signal absorption, brief periods of strong
> signal enhancement, which is mainly caused by tilts in the
> ionosphere that allow signals to become focused at your
> location or very erratic signal behavior in the form of
> strong and rapid fading, etc., caused by a variety of effects
> such as multi-pathing, anomalous and rapid variations in
> absorption, non-great-circle propagation, horizontal or side
> refraction and/or scatter (skewing) due to changes in
> electron density and polarization changes. (See definition
> #7. Propagation Path Skewing).....
>
>
> The bottom line is that propagation conditions will vastly
> improve on the MF AM broadcast band, 160 and 120 meters on
> the upside of solar cycle 24 in
> 2009 and 2010.
>
>
> 73,
> Thomas F. Giella, KN4LF
> Lakeland, FL, USA
> kn4lf@arrl.net
>
> KN4LF Daily Solar Space Weather & Geomagnetic Data Archive:
> http://www.kn4lf.com/kn4lf5.htm
> KN4LF Daily LF/MF/HF/6M Frequency Radiowave Propagation
> Forecast & Archive
> Site: http://www.kn4lf.com/kn4lf6.htm
> KN4LF 160 Meter Radio Propagation Theory Notes:
> http://www.kn4lf.com/kn4lf8.htm
> LF/MF/HF/VHF Frequency Radiowave Propagation Email Reflector:
> http://montreal.kotalampi.com/mailman/listinfo/kn4lf
>
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