Archive for the ‘Uncategorized’ Category

Global Overlay Mapper ham radio mapping suite gets major update

global-overlay-mapping

The Global Overlay Mapper has been around for some years. The previous version was built as a series of browser pages within a Windows shell, and reached the end of its life once Window introduced ‘User Account Control’, making remote updating too difficult. At the time I was away from Ireland, back-packing around the world as a pro-travel photographer (http://www.gnomeplanet.com/) for 8 years.

Now back home again, I decided to completely re-write the Global Overlay Mapper as a proper Windows program that was compatible with Win 7, 8, and 10. Its 38 maps were updated to include all the new countries, prefixes, flags, and IOTA entities. (The Global Overlay Mapper is the only ham map-suite that displays all IOTA entities.) As a proper Windows program, I could now add a variety of features that I’d been planning for some time. You can now geocode a Cabrillo or ADIF log – in other words, you can add positions to each QSO and then plot your log on a map, thanks to the nice guys at HamQTH.Com. You can plot lists of positions or Maidenhead Locators. You can see, display, and plot callbook information. You can see real-time NCDXF Beacon transmission schedules, and plot the beacons.

The Global Overlay Mapper is ideal for every ham, no matter where their special field of interest might be. The local ragchewer, the HF and VHF dxer, International or Local Contester, Field Day Team, Emergency Communications Specialist, DXCC and Award Hunter, IOTA expeditioner; all will find the Global Overlay Mapper an important tool for everyday use. The Global Overlay Mapper is now shareware – it works for 30 days, then requires registration, which costs just USD15. If you registered a previous version, you can upgrade for just USD5.

To find out more, and download your copy, please visit:

http://www.mapability.com/ei8ic/gom/intro.php

Coax losses

If you are like me, then you always want to know the loss of your coax at 6m,2m and 70cm, possibly higher I found this very useful table to compare various coax cables at different frequencies. You may have your own favorite table! If not, I hope you find this one useful.

See http://www.w4rp.com/ref/coax.html .

2m big wheel

Well, I have ordered one (yes I know I could have made one although not in my present state) so I hope this can be erected in the next few weeks, although I shall need help to do this as I am no good on ladders in my current poor state of health. It would be good if I could get a long wire erected at the same time for LF/MF use, although this could wait. At this time I am going for a single big-wheel rather than a stack.

I have decided against buying a 70cm big wheel at the same time as this would require a new length of low loss cable too. I also checked my existing low loss cable and this seems in good condition, so it will be reused. I may make my combined 2m/70cm antenna into a portable antenna when I have found out why the VSWR is poor.

See https://sites.google.com/site/g3xbmqrp3/antennas/bigwheel .

Amateur Radio Weekly – Issue 72

FreeDV QSO Party Weekend
The Amateur Radio Experimenters Group would like to invite all amateurs interested in HF digital voice communications to join us on the weekend of September 12th and 13th in a FreeDV Codec2 digital HF voice QSO Party!
AREG

Do not Digipeat via PCSAT
Although this is the correct frequency for APRS operation in IARU Region 2, it is not compatible with our Region 1 bandplan.
AMSAT UK

My Amateur Radio bucket list. What’s yours?
There is just so many possible things you can do within the hobby that it could possibly take a lifetime to achieve.
NT1K

Chinese Amateur Radio Satellites set to launch in early September
The XW-2 series satellites are equipped with substantially identical Amateur Radio payloads — a U/V mode linear transponder, a CW telemetry beacon and an AX.25 19.2k/9.6k baud GMSK telemetry downlink.
ARRL

Simplex, Duplex, Offset and Split
Simplex is a term that applies on all of the ham bands, because it is the simplest way to communicate. However, it is not the “opposite” of using a repeater.
Ham Radio School

What happened when I added a counterpoise to my HT
By adding a 1/4-wave counterpoise, you, in effect, turn the antenna into an off-center-fed, vertically polarized 1/2-wave dipole.
KC4LMD

Facebook. What is it good for?
Notable Amateur Radio Facebook Groups.
W2LJ

DX from Bald Ledge
EA5GX Sergio in Spain was calling CQ and we made a quick contact. There was some QSB, but he gave me a 579. Finally, I heard LZ1GU in Bulgaria calling CQ. Harry was strong and he gave me a 569.
amateurradio.com

In Pacific islands, radio remains the most accessible news source
Newspapers are a luxury item. On average, each newspaper in the Pacific will be read by seven people, which helps explain why the daily paper’s print run is so low.
The Saturday Paper

How to

QRV from a new apartment
This mainly amounted to mounting and tuning my 20m hamstick and running cable to the radio. This doesn’t sound like much on paper but it was a lot more engineering than that.
W0EA

Video

Ham Radio fun with tropospheric ducting propagation
This is a sample of stations I worked or heard during a nice tropospheric ducting 2 meter band opening from my location in Albert Lea, Minnesota.
RadioHamGuy

Homemade yagi antenna field test
I demonstrate some local QRM that I have been receiving there, check access to 4 distant repeaters (GB3SC, GB3JB, GB3WH and GB3VA), and have a nice QSO with Andy (G6TRW).
YouTube

Amateur radio enthusiast contacts space station
We live in a world fascinated by space, but very rarely does the ordinary man reach up into the stars for a chat.
CNN

New versions K1JT weak signal digital modes

Bob, G3WKW, has passed on this information from Joe Taylor K1JT:

“Date: Fri, 07 Aug 2015 16:28:19 -0400

Several people have asked for an update on development of the “Fast modes” in WSJT and WSJT-X.  So here’s a brief summary.

First, a review of some relevant terms and motivations.  It’s convenient to think of the various WSJT protocols (“modes”) in two groups:

*Slow modes* — JT4, JT9, JT65, and WSPR.  These modes are designed for communication with extremely weak signals — often too weak to be heard. Target propagation modes include EME and long-distance troposcatter on HF-and-up bands, and QRP Dxing on the LF, MF, and HF  bands.  Relevant signal amplitudes are approximately constant over a minute and more, aside from so-called “libration fading” for EME. Transmit/receive sequences are 1 minute for JT4, JT9, and JT65, and 2 minutes for WSPR.

*Fast modes* — JTMS, FSK441, ISCAT, and JT6M — and now also *FSK315* (implemented in WSJT) and *JT9E* through *JT9H* (implemented in WSJT-X. These modes are made for communication with rapidly varying signals:for example, meteor scatter, ionospheric scatter, airplane scatter, and scatter off the International Space Station.  The decoders are designed take advantage of short enhancements of signal strength.  T/R sequences are 30 seconds (or sometimes even shorter).

Bill, ND0B, has implemented a trial version of FSK315 in WSJT.  Think of this mode as FSK441 slowed down to 315 baud; the bandwidth is therefore narrow enough to make the mode legal in the “CW and data” portion of the 10 meter band.  Bill and a few others have been experimenting with FSK315 and also ISCAT-A on 10 meters, under dead-band conditions, using meteors and ionospheric scatter propagation.

I have implemented experimental submodes of the JT9 protocol in the program branch WSJT-X v1.6.1.  As with JT4 and JT65, letters following the “JT9” designator indicate increased spacings between the FSK tones. Traditional JT9 (now also called JT9A) has tone spacing 1.736 Hz, so the signals used at HF and below have total bandwidth 9*1.736 = 15.6 Hz.  The widest of the new submodes, JT9H, has tone spacing 200 Hz and therefore bandwidth 9*200 = 1800 Hz.

When used with the standard 1-minute periods, the wide JT9 submodes should be useful for the same purposes as the wide JT4 submodes: microwave EME, for example, where libration fading can cause Doppler spreading of 100 Hz or more.  Used in this way, all JT9 submodes are “slow” modes; they use 1-minute T/R periods and keying rate 1.736 baud, and they send the full 85-symbol message protocol in 85/1.736 = 48.96s.

Optionally, the wide JT9 submodes can now also use “fast” keying rates equal to their tone spacing.  “Fast JT9H”, for example, uses keying rate 200 baud, so the full message protocol is transmitted in 85/200 = 0.425s.  The message is sent repeatedly for the full Tx period, in the same way as done for the other fast modes.

The fast JT9 submodes should be very effective for meteors and ionoscatter propagation, especially on the 6 meter band.  Sensitivity should be similar to ISCAT, or perhaps slightly better.  Because JT9 includes strong forward error correction, decoding results are like those for all the slow modes: you should see messages exactly as they were transmitted, or nothing at all.

Tests of the fast JT9 submodes are currently under way, with excellent results.

   — 73, Joe, K1JT”

So just how sporadic is sporadic E (Es)?

Time and again I have been struck by just how unsporadic Es is. OK, good days are random but there seems to be a pattern that more northerly and Scandinavian stations on 10m and 6m are better later in the day and later in the season. I actually wonder if these more northerly reports really are Es at all. There is every chance I am totally wrong, but I have noticed this over several summers and I question that Es is truly “sporadic”. I’d be interested to hear the views of others on this.

One thing is certain: we still have a great deal to learn about E-layer DX propagation. Es is certainly a fact on many summertime EU QSOs on the higher HF bands and 6m, but I am sure the multi-hop explanation for some very long distance QSOs is not right.

Our Amazing Sun and HF Radio Signal Propagation

Space Weather. The Sun-Earth Connection. Ionospheric radio propagation. Solar storms. Coronal Mass Ejections (CMEs). Solar flares and radio blackouts. All of these topics are interrelated for the amateur radio operator, especially when the activity involves the shortwave, or high-frequency, radiowave spectrum.

Learning about space weather and radio signal propagation via the ionosphere aids you in gaining a competitive edge in radio DX contests. Want to forecast the radio propagation for the next weekend so you know whether or not you should attend to the Honey-do list, or declare a radio day?

In the last ten years, amazing technological advances have been made in heliophysics research and solar observation. These advances have catapulted the amateur radio hobbyist into a new era in which computer power and easy access to huge amounts of data assist in learning about, observing, and forecasting space weather and to gain an understanding of how space weather impacts shortwave radio propagation, aurora propagation, and so on.

I hope to start “blogging” here about space weather and the propagation of radio waves, as time allows. I hope this finds a place in your journey of exploring the Sun-Earth connection and the science of radio communication.

With that in mind, I’d like to share some pretty cool science. Even though the video material in this article are from 2010, they provide a view of our Sun with the stunning solar tsunami event:

On August 1, 2010, the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple plasma-filled filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more!

At approximately 0855 UTC on August 1, 2010, a C3.2 magnitude soft X-ray flare erupted from NOAA Active Sunspot Region 11092 (we typically shorten this by dropping the first digit: NOAA AR 1092).

At nearly the same time, a massive filament eruption occurred. Prior to the filament’s eruption, NASA’s Solar Dynamics Observatory (SDO) AIA instruments revealed an enormous plasma filament stretching across the sun’s northern hemisphere. When the solar shock wave triggered by the C3.2-class X-ray explosion plowed through this filament, it caused the filament to erupt, sending out a huge plasma cloud.

In this movie, taken by SDO AIA at several different Extreme Ultra Violet (EUV) wavelengths such as the 304- and 171-Angstrom wavelengths, a cooler shock wave can be seen emerging from the origin of the X-ray flare and sweeping across the Sun’s northern hemisphere into the filament field. The impact of this shock wave may propelled the filament into space.

This movie seems to support this analysis: Despite the approximately 400,000 kilometer distance between the flare and the filament eruption, they appear to erupt together. How can this be? Most likely they’re connected by long-range magnetic fields (remember: we cannot see these magnetic field lines unless there is plasma riding these fields).

In the following video clip, taken by SDO AIA at the 304-Angstrom wavelength, a cooler shock wave can be seen emerging from the origin of the X-ray flare and sweeping across the sun’s northern hemisphere into the filament field. The impact of this shock wave propelled the filament into space. This is in black and white because we’re capturing the EUV at the 304-Angstrom wavelength, which we cannot see. SDO does add artificial color to these images, but the raw footage is in this non-colorized view.

The followling video shows this event in the 171-Angstrom wavelength, and highlights more of the flare event:

The following related video shows the “resulting” shock wave several days later. Note that this did NOT result in anything more than a bit of aurora seen by folks living in high-latitude areas (like Norway, for instance).

This fourth video sequence (of the five in the first video shown in this article) shows a simulation model of real-time passage of the solar wind. In this segment, the plasma cloud that was ejected from this solar tsunami event is seen in the data and simulation, passing by Earth and impacting the magnetosphere. This results in the disturbance of the geomagnetic field, triggering aurora and ionospheric depressions that degrade shortwave radio wave propagation.

At about 2/3rd of the way through, UTC time stamp 1651 UTC, the shock wave hits the magnetosphere.

This is a simulation derived from satellite data of the interaction between the solar wind, the earth’s magnetosphere, and earth’s ionosphere. This triggered aurora on August 4, 2010, as the geomagnetic field became stormy (Kp was at or above 5).

While this is an amazing event, a complex series of eruptions involving most of the visible surface of the sun occurred, ejecting plasma toward the Earth, the energy that was transferred by the plasma mass that was ejected by the two eruptions (first, the slower-moving coronal mass ejection originating in the C-class X-ray flare at sunspot region 1092, and, second, the faster-moving plasma ejection originating in the filament eruption) was “moderate.” This event, especially in relationship with the Earth through the Sun-Earth connection, was rather low in energy. It did not result in any news-worthy events on Earth–no laptops were fried, no power grids failed, and the geomagnetic activity level was only moderate, with limited degradation observed on the shortwave radio spectrum.

This “Solar Tsunami” is actually categorized as a “Moreton wave”, the chromospheric signature of a large-scale solar coronal shock wave. As can be seen in this video, they are generated by solar flares. They are named for American astronomer, Gail Moreton, an observer at the Lockheed Solar Observatory in Burbank who spotted them in 1959. He discovered them in time-lapse photography of the chromosphere in the light of the Balmer alpha transition.

Moreton waves propagate at a speed of 250 to 1500 km/s (kilometers per second). A solar scientist, Yutaka Uchida, has interpreted Moreton waves as MHD fast-mode shock waves propagating in the corona. He links them to type II radio bursts, which are radio-wave discharges created when coronal mass ejections accelerate shocks.

I will be posting more of these kinds of posts, some of them explaining the interaction between space weather and the propagation of radio signals.

For live space weather and radio propagation, visit http://SunSpotWatch.com/. Be sure to subscribe to my YouTube channel: https://YouTube.com/NW7US.

The fourth video segment is used by written permission, granted to NW7US by NICT. The movie is copyright@NICT, Japan. The rest of the video is courtesy of SDO/AIA and NASA. Music is courtesy of YouTube, from their free-to-use music library. Video copyright, 2015, by Tomas Hood / NW7US. All rights reserved.


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