Archive for the ‘hamfeed’ Category

A Solar flare, A CME, A Proton Storm: Magnitude M2.5 X-ray Flare

Watch this amazing explosion on the Sun. From sunspot complex 1226-1227 comes an X-ray Flare peaking at a magnitude of M2.5 at 0640 UTC on 7 June, 2011.

Source: https://www.youtube.com/watch?v=KQMrRu8BWDo

This X-ray flare hurled a massive coronal mass ejection (CME) toward the Earth. This not-squarely Earth-directed CME is moving at 1400 km/s according to NASA models. The CME did not deliver even a noticeable glancing blow to Earth’s magnetic field late June 8th or June 9th.

What can be seen clearly in this movie is one of the most spectacular prominence eruptions ever observed. In fact, one could call it a “prominence explosion”. The prominence material expanded to a volume some 75 times as big across as the earth!

This X-ray flare also triggered an S1-level solar radiation storm, causing a long-lasting polar cap absorption (PCA) event. A polar cap absorption (PCA) event affects the propagation of a shortwave radio signal as it makes its way over the polar regions. In short, radio communications on lower shortwave radio frequencies become more difficult, as those radio signals are absorbed by the ionosphere (in the D-region) over the polar regions.

What does this mean in real-world communications? Trans-polar airline pilots may find it more difficult to communicate with regional air traffic control, shortwave radio listeners who want to hear a broadcast from a country by receiving a transmission from a country by way of a transmission beamed over the pole (like, from Europe into the USA via the North Pole), or other such communications, will find those signals all but gone. The stronger the PCA event, the higher the frequencies absorbed over the polar regions, with the greatest absorption occurring at the lower frequencies.

This movie spans the period of time from 0300 UTC through 1556 UTC, and is composed of the 171-Angstrom, 304-Angstrom, and 335-Angstrom wavelength views as captured by the filters of the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA). In this movie, the AIA instruments capture the Sun’s extreme ultraviolet light and reveal a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material–at temperatures less than 80,000 K.

The following is a linked video that is part of this event: http://www.youtube.com/watch?v=L4CsjcUGoaw

Watch as we zoom out to see a total view of the June 7, 2011 moderately-powerful X-ray Flare and Prominence Eruption. This movie will give you a full perspective of the immense size of this prominence eruption as it spews out away from the Sun.

The X-ray Flare peaked at a moderate magnitude of M2.5 at 0640 UTC, but unleashed a huge prominence eruption. The massive cloud of plasma was ejected out into interplanetary space, but missed the Earth. This movie stars with a “close-up” view by the Solar Dynamics Observatory at a combined wavelength view at 94 and 304 Angstroms. Then, the movie views the event further back through the eyes of the COR1 spacecraft (with the SDO AIA 304 image superimposed in the middle). Next, we zoom out to the COR2 spacecraft and superimpose the COR1 and SDO views. Then, we zoom further back to the H1 view… and finally look again at the event close-up.

More info: http://sunspotwatch.com/

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Source: SDO AIA NASA SOHO

Unboxing the Icom IC-F4161DT NXDN Radio

Unboxing the Icom IC-F4161DT

As my wife would say, I am at it again with radios. I just picked up the Icom IC-F4161DT NXDN Radio. If you do not know much about NXDN I would recommend that you check out these few pages:

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

http://www.nxdn-forum.com/

The reason I jumped aboard is that my club NI4CE has taking the leap with our 10 country coverage of repeaters we have started the process of updated them to NXDN. http://www.ni4ce.org/nxdn/

Here is a blurb, but you could read more at their site: Earlier this year, the West Central Florida Group, Inc. made a strategic decision to replace the D-Star digital repeater at Riverview with an industry standard NXDN repeater from ICOM. In addition, the new ICOM FR6000 UHF repeaters now in service at Verna (442.950 MHz) and Holiday (443.450 MHz) also support MIXED mode 25 KHz analog voice and 6.25 KHz NXDN digital communications on demand.

I decided that it was time for me to think about this challenge since I always like to be on the latest technologies and also I love radios ☺ I think we all know that by now if you have read my articles about Ham Radio.

Full post: http://nicktoday.com/unboxing-icom-ic-f4161dt-nxdn-radio/

 


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  • Matt W1MST, Managing Editor




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