TV-DX: F2 vs. Sonnenflecken-Minimum

Startbeitrag von Mathias Volta am 30.05.2009 15:44

Der rumänische DXer Daniel (Youtube: "zvartoshu") schrieb mich gestern an und schickte mir folgende Bild-Links mit der Frage bzw. Vermutung, ob hier TV-DX aus der Region Asien speziell China via F2 vorläge:

http://i87.servimg.com/u/f87/12/17/05/46/p1070210.jpg

http://i87.servimg.com/u/f87/12/17/05/46/p1070211.jpg (=> Original-Bild vom 26.05.2009)

Daraufhin antwortete ich ihm folgendes und erläutere ihm neben den bekannten Basics zu F2 mit einigen interessanten Links meine Vermutung, daß - wenn überhaupt - hier eher Mulithop-ES vorliegen könnte (der Einfachheit halber Original-Text):

Hi Daniel,

F2 can be definitively(!!) closed out:
1.) we have absolute sun spot minimum - that close out F2 (F2 is usually possible during high sunspot maximum, which can be expected up from the year 2012.
2.) a picture, which is characteristic of F2, would be much more smeared due to running differences in atmosphere.
3.) F2 usually appears in autumn & winter on ch E2 or R1, A2, C1, etc... Highest possible MUF below 60 MHz.

Lowest chinese VHF-I channel frequency mainly used by CCTV and other stations there:
ch C1 - video: 49,75 MHz / audio: 56,25 MHz

Multihop-sporadic-e? Maybe...
But I cannot believe that because it was a quiet day today - personally haven't had sporadic-e today.
Other possibility: You did receive news from one of your ordinary TV-channels, you often get via sporadic-e: In these news they informed about China or so and used original material from CCTV. This is often the case, when information about China are shown in German news and the original material by CCTV often displays chinese letters.
Maybe you should request a professional TV-DXer in skywaves.

Usefull information:

http://www.geocities.com/TelevisionCity/Lot/2941/f2/f2.htm

http://www.lyngsat-logo.com/logo/tv/aa/armenia1.jpg

http://www.lyngsat-logo.com/tvcountry/tvcountry.html

http://en.wikipedia.org/wiki/F2_propagation

http://en.wikipedia.org/wiki/TV_DX

http://dxinfocentre.com/f2/yvva/YVVA.html

http://blogs.myspace.com/index.cfm?fuseaction=blog.view&friendId=331781989&blogId=357155900

Greetings,
Matze


Daniel kontaktierte auch einen anderen DXer, mit dem ich wiederum nicht in Kontakt stehe, leitete diesem meine PM weiter und bekam folgende interessante Antwort:

Hmmm, Mathias says an interesting and real thing until one point. We all know that F2 is ABSOLUTELY impossible in low solar flux year.
But... seems that something is absolutely strange in the solar activity in this days. I'm watching at the solar flux of 68, which is in the deep hole of minimum possible. But the bands are working very strange, specially the higher part of shortwaves. My experience since 1996 (another deep hole of solar activity)says that, in the minimum activity years, in 27MHz, any long distance propagation (outside Europe) received in east Europe, Romanian area, is transecuatorial. Mourning is only west Australia, during the day Reunion and South Africa, and in the evening only the east coast of South America, from the extrem south to, not more than, Rio de Janeiro and Sao Paulo. And very weak signals so you need beam or vertical 5/8 wave antenna and around 300-400W to work them in SSB. When propagation is better (like it was, for example, from February 1998 to something like 2004) for example the South American area availlable to work from Romania is extending to the north, the openings with French Guyana become something normal, than comes Trinidad & Tobago, than, when the sun is enough active (remember April-Mai 1998) you can catch the East Coast of States. And the signals are stronger and stronger... That's the rule in CB.
So... what is strange for me is that, few days ago, in CB we had a strong (and, believe it... STRONG) opening with Trinidad and Tobago. And this in a moment when solarcycle24.com reported no more than 72 the solar flux. What the hell is this kind of propagation, or... what's happening with the sun?

So... in this moment, I can't say that F2 is totally impossible in 50MHz. We need to stay tuned in tha HAM radio band to see what's coming there

Another strange thing for me was in 26 May 2009, in that "DX day". We all know that zvartoshu has an antenna which is working good for TV DX. And youtube is full of his movies. But... when I receive simultanously, 2 locations from Russia 1, via e-skip, with ONLY two VHF3 dipoles, something is strange. So, in that evening (I didn't want to make waves but zvartoshu knows), around... 23 local time (20 UTC)when the opening was really strong, I've got two locations (in 49.25, maybe R1 and in 59.25, which I think is R2) from the very known russian translucent "1" hanging in the upper right corner of the screen. Sometimes with clear signal and, one of those (I don't remember if R1 or R2) with russian sound smile.gif . And also in E channels some very low mixing signals (if they didn't become clear I didn't talk about them, considering extremely low level signals as not important). And all these with the "antenna" (the two VHF3 dipoles) beaming somewhere around 45-60 degrees from my position (the border between KN34AJ and KN34AK, south-west Bucharest). So... what's up with this strange propagation? I don't want to make offtopic here to say that tropo in the last 5 nights was lower than it was in the frozen nights of winter. I say now only about the strange e-skip openings.
So, there, in this moment I'm not able to say any kind of prediction about what is possible and what not. I don't exclude anything smile.gif

73's from Radu - YO3GUP


Jetzt meine Fragen an euch:
- Wäre F2 im bezüglich auf die in meiner Mail oben erwähnten und generell bekannten Basics zu F2 wirklich vollkommen ausgeschlossen, wie ich schon vermute, Radu (YO3GUP) jedoch nicht ganz, oder
- liegt doch eher Multihop-ES vor, was ich mir schon eher vorstellen kann auch im Hinblick auf die oben verlinkten Screenshots, die meiner Meinung nach auch nicht die wirklich F2-typischen Empfangscharacteristica wie durch Laufzeit-Differenzen verursachte "Geisterbilder" zeigen?
- ...oder doch vielleicht nur eine ganz gewöhnliche via ES empfangene Nachrichten-Sendung, die einen Original-Beitrag von CCTV o.ä. zeigt?
Leider kann ich auf den oben verlinken Bildern außer den vermutlich chinesischen Schriftzeichen keine Logos oder anderen Anhaltspunkte erkennen.

Antworten:

Zur Information:
MySnip.de hat keinen Einfluss auf die Inhalte der Beiträge. Bitte kontaktieren Sie den Administrator des Forums bei Problemen oder Löschforderungen über die Kontaktseite.
Falls die Kontaktaufnahme mit dem Administrator des Forums fehlschlägt, kontaktieren Sie uns bitte über die in unserem Impressum angegebenen Daten.