Tag Archives: Propagation

USAF wants to release ionized gas in the upper atmosphere to improve HF

New Scientist magazine reports the US Air Force is working on plans to improve HF radio propagation by releasing ionised gas in the upper atmosphere using a fleet of micro satellites

As well as increasing the range of radio signals, the USAF says it wants to smooth out the effects of solar winds, which can knock out GPS, and also investigate the possibility of blocking communication from enemy satellites.

The story says there are at least two major challenges. One is building a plasma generator small enough to fit on a CubeSat – roughly 10 centimetres cubed. Then there’s the problem of controlling exactly how the plasma will disperse once it is released.

Read the story at
https://www.newscientist.com/article/2100382-us-air-force-wants-to-plasma-bomb-the-sky-using-tiny-satellites/

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Some scientists believe sun may be crossing into “magnetic middle age”

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(SILSO data/image, Royal Observatory of Belgium, Brussels)

I just received the following link to a Forbes article from my buddy Charlie (W4MEC).

If this research turns out to be correct–and time will only tell–it could mean very low solar activity from here on out (let’s hope not!):

(Source: Forbes Magazine via Charlie W4MEC)

The Sun has likely already entered into a new unpredicted long-term phase of its evolution as a hydrogen-burning main sequence star — one characterized by magnetic sputtering indicative of a more quiescent middle-age. Or so say the authors of a new paper submitted to The Astrophysical Journal Letters.

Using observations of other sunlike stars made by NASA ’s Kepler Space Telescope, the team found that the Sun is currently in a special phase of its magnetic evolution.

At time of posting (June 28, 2016) the Sun has no Sun spots at all, which means very low solar activity. Credit: SDO/HMI (Click to enlarge)

Heretofore, the Sun was thought to have been just a more slowly rotating version of a normal yellow dwarf (G-spectral type) star. These results offer the first real confirmation that the Sun is in the process of crossing into its magnetic middle age, where its 11-year Sunspot cycles are likely to slowly disappear entirely. That is, from here on out, the Sun is likely to have fewer sunspots than during the first half of its estimated 10 billion year life as a hydrogen-burning star.

“The Sun’s 11-year sunspot cycle is likely to disappear entirely, not just get less pronounced; [since] other stars with similar rotation rates show no sunspot cycles,” Travis Metcalfe, the paper’s lead author and an astronomer at the Space Science Institute in Boulder, Colo., told me.[…]

Continue reading the full article at Forbes online.

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Excellent current conditions, evidenced by today’s 31 meter logs

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This morning, before heading out the door, I tuned around the 31 meter broadcast band. I’ve actually been recording 640 kHz of the 31 meter band for almost 24 hours, trying to capitalize on the fact that propagation conditions have been the best I’ve seen in several months. At some point in the future, I’ll load this recording, tune through it and remind myself what’s possible when propagation is favorable! Check out the waterfall screenshot above.

Asian stations had a strong showing on the band in eastern North America this morning.

Here are the stations I logged starting around 12:30 UTC today:

9395 WRMI English
9410 China National Radio 5 Chinese
9420 China National Radio 13 Uyghur
9430 FEBC Radio Chinese
9440 China Radio International Cambodian
9460 China Radio International English
9470 UNID (weak)
9490 Voice of America Korean
9500 China National Radio 1 Chinese
9515 China National Radio 2 Chinese
9540 China Radio International Chinese
9550 Radio Havana Cuba Spanish
9570 China Radio International Cantonese
9575 All India Radio Tibetan
9580 Radio Australia English
9600 China Radio International English
9620 All India Radio Sindhi
9635 Voice of Vietnam 1 Vietnamese
9640 Radio Havana Cuba Spanish
9645 China Radio International English
9650 Radio Sonder Grense Afrikaans (with QRM)
9660 Radio Taiwan International Chinese
9665 KCBS Pyongyang Korean (weak)
9680 Radio Taiwan International Chinese
9700 Radio New Zealand International English
9710 China National Radio 1 Chinese
9720 Reach Beyond Australia (HCJB) Indonesian
9730 China Radio International English
9735 Radio Taiwan International Indonesian
9740 BBC English
9750 NHK World Radio Japan (?) Japanese
9760 China Radio International English
9785 China Radio International Laotian (?)
9805 Radio Marti Spanish (w/accompanying Cuban jammer)
9820 Radio Habana Cuba Spanish
9830 China National Radio 1 Chinese (with RTTY QRM)
9835 RTM Sarawak FM Malaysian (very weak)
9840 Voice of Vietnam English
9845 China National Radio 1 Chinese (weak)
9855 China Radio International Chinese
9870 AIR New Delhi Hindi
9880 KSDA-AWR Guam Korean
9920 FEBC Radio Hre
9955 WRMI English
9980 WWCR English
10000 WWV Ft. Collins

That’s 46 signals in a space of 640 kHz–not bad!

I dare say: these excellent band conditions will not last forever.

Make time to play radio today!

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The bands are open! Make time to listen.

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Though I’ve spent the entire day sawing and splitting firewood, I’ve been actively recording spectrum on the 31, 25, 19 and 16 meter bands with the WinRadio Excalibur, Elad FDM-S2 and the SDRplay RSP. Why? Propagation–especially on the higher bands–has been the best it’s been in several weeks.

As I discovered at the recent SWLing Post DXpedition, my shack PC can handle making multiple spectrum recordings simultaneously as long as I limit each recording to the width of a broadcast band. (I’ve never tried pushing the limit very hard.) Someday in the future–perhaps when we’re having terrible propagation–I’ll play those spectrum recordings back and tune through them as if they were live.

Radio time travel at its best.

Sony-ICF-SW100-Outside-2

When I decided to throw in the towel with all of the firewood processing, I fired up the Sony ICF-SW100 (above) and tuned in a game on 17,855 kHz: Radio Exterior de España.

The REE signal was simply booming into eastern North America!

Hard to break away from the radio on days like this.

My advice? Take advantage of these conditions and make time to listen!

For me, SWLing a great excuse to relax and let me back heal after a long day of splitting wood. For some, perhaps it’s a good excuse to take the radio outdoors and away from urban interference. Whatever the excuse, don’t hesitate to fire up your radio!

There are some interesting stations on the bands this evening. Feel free to comment with some you’ve logged.

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Met Office guide to space weather forecasts

Bill solves the CRI echo mystery

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A few days ago, I posted an article about Bill Meara (producer of the SolderSmoke Podcast) who was hearing audio echoes on his home brew regenerative receiver.

Bill has now solved this mystery (hint: it’s all about the receiver):
http://soldersmoke.blogspot.com/2014/09/radio-china-international-echo-mystery.html

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Hearing echoes on China Radio International

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Bill Meara, producer of the popular SolderSmoke Podcast, recently recorded audio echoes on a couple of his home brew regenerative receivers. Bill posted the following video, of his regen receiver tuned to China Radio International:

After Bill measured the echo delay at .133 seconds, he believes one possibility is that they originate from a propagation opening much like Lyle recorded on a 10 meter band opening last year (click here to listen to the audio and read the post).

A few days later, Bill recorded a similar echo effect while tuned to Brother Stair (Overcomer Ministries) on a different regenerative receiver. Click here to read the post and view the video.

The fact that Bill measured a .133 second delay (the amount of time it would take for a signal to circle the globe), makes me believe he’s hearing an echo similar to Lyle. But I must admit, I’m a bit amazed that a faint AM echo could penetrate blowtorch signals like CRI and Brother Stair’s relay generate State side.

Readers: What’s going on here? Is Bill catching rare propagation openings–or perhaps ducting in the Earth’s magnetosphere and ionosphere–or is there another explanation?

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