View Full Version : Strange conditions today

14-07-2005, 10:32

over here, 7 MHz has gone completely silent at around 10:20 UTC, 6 and 9 MHz are also affected, 12 and 15 MHz signals are extremely weak.
Looks pretty much like an ionospheric (Mögel-Dellinger) disturbance.

What a good opportunity to check for local interference sources as they will be the only signals one can still receive. ;-)


14-07-2005, 13:54
Hi Roland and all,

the same happened here.
My DRT1 was running unattended this morning on DW 3995kHz.
From the log you can see that something happened around 05:30 UTC.

14-07-2005, 14:55
Hi Roland and all,
today was the third day in a row that this happened, but the other days it did not last for such a long period of time.
73, Simone

14-07-2005, 19:21
Hi all,

Same here in Hilversum. Looks we had some strong solar flares today which caused a lot of D-layer attenuation up to almost 17 MHz.

Indeed only local interference could be heard here. At the same time very good propagation on 50 MHz.

I got a telephone call from one of our listeners in France during my lunchbreak today if we could solve the technical problem :-)

btw: www.ips.gov.au is an interesting site to monitor such events in real time

Jan Peter

14-07-2005, 19:45
Originally posted by JanPeterW
btw: www.ips.gov.au is an interesting site to monitor such events in real time

Thanks for the link. But it is not so easy to find and interpret the appropriate information on this page, once the event is over.
I have found the following under X-Ray Flares, where the start of the event coincides well with my own observations:
Approximate Flare Start : 14-07-2005 1018 UT
Approximate Flare Maximum: 14-07-2005 1054 UT at Flux X 1.3
Approximate Flare End : 14-07-2005 1312 UT
LOCATION OF HF FADEOUT: Sthn Africa/South Africa (RSA)/Central Africa/North Africa/Europe/Western Russia/South Atlantic/Middle East/


07-07-2006, 05:59

I think the strange conditions yesterday were caused by a heavy M2.5 magnitude Solar Flare (gev_20060706_0813) which kept going for the the rest of the day yesterday.

If you use Firefox as your Web browser there is a practical plug-in which shows the "radio weather" in a small window at the lower right when browsing the www. Firefox can be found here: http://www.mozilla.com/firefox/releases/
and the Plug-in here: https://addons.mozilla.org/firefox/1253/

For those interested, some interesting web addresses are:
SolarSoft latest events: http://www.lmsal.com/solarsoft/latest_events/
3 Days GOES Space Weather: http://www.sec.noaa.gov/today.html
Spaceweather: http://spaceweather3.com/

Ionograms are quite interesting and give you an idea of what's going on.
Germany: http://www.iap-kborn.de/radar/Radars/Ionosonde/iono_plots.php
Belgium: http://digisonde.oma.be/cgi-bin/latest.exe?
Spain: http://dgs.obsebre.es/latestFrames.htm

Aurora activity: http://www.spaceweather.noaa.gov/pmap/pmapN.html


05-12-2006, 11:40
An X9 flare from the sunspot 929 knocked out reception completely for a while on all bands from 6 MHz and up from around 1035 - 1045 UTC. Just in case you wonder what caused the dropouts.

Or, maybe it was sunspot 930?

15-12-2006, 10:48
This morning was a perfect time to study DRM under severe Aurora conditions. Not much at all to hear this morning from 5 thru 12 MHz. The sun spot 930 is still alive and kicking! Now, if this is happening during the sunspot minimum, you might wonder what it would be like 4-5 years from now... :eek:

Smart move by DW to lower the bitrate during the transmission.

Below is a table with my observations tuning the Short Wave band at 0745 UTC: