Posts Tagged ‘amateur radio’
Watch stunning highlights, last 5 years of the Sun
We rely on the Sun for HF radio communication propagation. For the last five years, we have an amazing front-row seat: the SDO spacecraft. Here is a video with highlights of the last five years of solar activity as seen by NASA and the SDO AIA spacecraft. This is worth seeing on a larger monitor, so try to view it full screen on something larger than your palm. The music is pretty good too. It is worth the 20-some minutes of stunning viewing. Be sure to share!
Enjoy!
Details:
This video features stunning clips of the Sun, captured by SDO from each of the five years since SDO’s deployment in 2010. In this movie, watch giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the Sun’s surface.
April 21, 2015 marks the five-year anniversary of the Solar Dynamics Observatory (SDO) First Light press conference, where NASA revealed the first images taken by the spacecraft. Since then, SDO has captured amazingly stunning super-high-definition images in multiple wavelengths, revealing new science, and captivating views.
February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory, which provides incredibly detailed images of the whole Sun 24 hours a day. February 11, 2010, was the day on which NASA launched an unprecedented solar observatory into space. The Solar Dynamics Observatory (SDO) flew up on an Atlas V rocket, carrying instruments that scientists hoped would revolutionize observations of the Sun.
Capturing an image more than once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the Sun grow and erupt. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.
The imagery in this “highlight reel” provide us with examples of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths (and therefore different temperatures, each “seen” at a particular wavelength that is invisible to the unaided eye) scientists can watch how material courses through the corona. SDO captures images of the Sun in 10 different wavelengths, each of which helps highlight a different temperature of solar material. Different temperatures can, in turn, show specific structures on the Sun such as solar flares or coronal loops, and help reveal what causes eruptions on the Sun, what heats the Sun’s atmosphere up to 1,000 times hotter than its surface, and why the Sun’s magnetic fields are constantly on the move.
Coronal loops are streams of solar material traveling up and down looping magnetic field lines). Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the Sun, achieves escape velocity and heads off into space.
This movie shows examples of x-ray flares, coronal mass ejections, prominence eruptions when masses of solar material leap off the Sun, much like CMEs. The movie also shows sunspot groups on the solar surface. One of these sunspot groups, a magnetically strong and complex region appearing in mid-January 2014, was one of the largest in nine years as well as a torrent of intense solar flares. In this case, the Sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.
Scientists study these images to better understand the complex electromagnetic system causing the constant movement on the sun, which can ultimately have an effect closer to Earth, too: Flares and another type of solar explosion called coronal mass ejections can sometimes disrupt technology in space as well as on Earth (disrupting shortwave communication, stressing power grids, and more). Additionally, studying our closest star is one way of learning about other stars in the galaxy.
Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.
Please visit my channel on YouTube, and subscribe ( https://YouTube.com/NW7US ).
— Twitter: https://Twitter.com/NW7US
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— Web: http://SunSpotWatch.com
( Data feed Twitter https://Twitter.com/hfradiospacewx )
Credits:
Music Via YouTube “Free-for-use” Creation Tools
Video clips of the Sun are from NASA’s Goddard Space Flight Center/SDO which are in the Public Domain
By the way, this is an example of what I am trying to produce on a more regular basis, once I launch the space weather YouTube channel that I have started. If you wish to help, here is the GoFundMe link: http://www.gofundme.com/sswchnl
Inverted High Frequency Loss with LMR-450G
By John ‘Miklor’ K3NXU
PERFORMANCE TESTS – LMR-450G
The recently announced LMR-450G cable has aroused much curiosity since its characteristics have not been collectively available by any one source. By multiple inquiries to several manufactures (only three at this time) and numerous lab tests, we hope to put many of the existing questions to rest.
DESCRIPTION
The physical make up of this cable varies slightly from most conventional RF cables. The center conductor is a semi-stranded copper alloy surrounded by Telfon, which will absorb and distribute cable ‘hot spots’ caused by excessive standing wave. The double silver braid and foil outer coating which provides a 98.6% shield is what the inverted high frequency loss characteristics are attributed. The loss is substantially less as the frequency increases, making this cable especially attractive for UHF, cellular, PCS and microwave applications.
LOSS PER 100′
30 MHz 2.4 db
50 MHz 2.1 db
150 MHz 1.6 db
450 MHz 1.1 db
800 MHz .51 db
1200 MHz .37 db
1950 MHz .31 db
The cable’s most unique property is attributed to the outer jacket material Neo-glow, an RF sensitive composite plastic which will visibly indicate RF ‘hot spots’ in the cable. Adjusting the cable length to the antenna system for the ‘perfect’ impedance match is crucial at high frequency, thus the importance of a low SWR for peak performance.
PROPER INSTALLATION
The low level emission of light from LMR-450G cable can be enhanced by wearing lightly tinted sunglasses with UV protection, which enhances the light radiation from the cable. Select an approximate length of cable needed for the installation which must be multiples of a 1/4 wavelength for the desired frequency. The exact length can be determined by using the formula 467 / Freq (MHz) plus approximately 18 inches.
The initial tests should be run with a 50 ohm dummy load at one end of the cable. With a minimum of 7 watts from the transmitter, you will see a faint glow from the cable indicating the ‘hot spots’ to be eliminated. These are the points along the cable where the RF is at its maximum. It is at these points where the RF connectors should be mounted. Trimming the excess cable may be required at both ends of the cable to produce the most effective match. Use caution not to trim too much cable as the loss characteristics improve with longer cable lengths.
SUMMARY
This could be the beginning of the long awaited high frequency “SUPER” cables. Only available in limited quantities at this time; contact your local cable supplier for more details.
Inverted High Frequency Loss with LMR-450G
By John ‘Miklor’ K3NXU
PERFORMANCE TESTS – LMR-450G
The recently announced LMR-450G cable has aroused much curiosity since its characteristics have not been collectively available by any one source. By multiple inquiries to several manufactures (only three at this time) and numerous lab tests, we hope to put many of the existing questions to rest.
DESCRIPTION
The physical make up of this cable varies slightly from most conventional RF cables. The center conductor is a semi-stranded copper alloy surrounded by Telfon, which will absorb and distribute cable ‘hot spots’ caused by excessive standing wave. The double silver braid and foil outer coating which provides a 98.6% shield is what the inverted high frequency loss characteristics are attributed. The loss is substantially less as the frequency increases, making this cable especially attractive for UHF, cellular, PCS and microwave applications.
LOSS PER 100′
30 MHz 2.4 db
50 MHz 2.1 db
150 MHz 1.6 db
450 MHz 1.1 db
800 MHz .51 db
1200 MHz .37 db
1950 MHz .31 db
The cable’s most unique property is attributed to the outer jacket material Neo-glow, an RF sensitive composite plastic which will visibly indicate RF ‘hot spots’ in the cable. Adjusting the cable length to the antenna system for the ‘perfect’ impedance match is crucial at high frequency, thus the importance of a low SWR for peak performance.
PROPER INSTALLATION
The low level emission of light from LMR-450G cable can be enhanced by wearing lightly tinted sunglasses with UV protection, which enhances the light radiation from the cable. Select an approximate length of cable needed for the installation which must be multiples of a 1/4 wavelength for the desired frequency. The exact length can be determined by using the formula 467 / Freq (MHz) plus approximately 18 inches.
The initial tests should be run with a 50 ohm dummy load at one end of the cable. With a minimum of 7 watts from the transmitter, you will see a faint glow from the cable indicating the ‘hot spots’ to be eliminated. These are the points along the cable where the RF is at its maximum. It is at these points where the RF connectors should be mounted. Trimming the excess cable may be required at both ends of the cable to produce the most effective match. Use caution not to trim too much cable as the loss characteristics improve with longer cable lengths.
SUMMARY
This could be the beginning of the long awaited high frequency “SUPER” cables. Only available in limited quantities at this time; contact your local cable supplier for more details.
‘USA 1776’ DMR Talk Group
One of the nice things of D-Star and DMR is the ability to talk all over the world without the need of an HF rig and a bunch of big antennas. While this largely reduces a radio to a simple Internet-driven communication tool – just like Skype or other VoIP apps – it’s definitely nice to use.
There are a few problems surrounding DMR, one of which is the lack of more than two time slots. For example, if hams are using the Dutch Hytera network and occupying talk group 204 on slot 1, World Wide (which uses the same time slot) will be unavailable. Because 204-1 is a busy place, world wide QSOs are often impossible. It’s one of the reasons I thought of dumping DMR all together — I can talk to the same Dutch guys on analog while enjoying a much better quality audio.
There are reasons to keep DMR too. DMR is maturing; there are more than enough possibilities to put less pressure on the nation-wide network by going local. Now if only hams would do that…. but most don’t. Another reason to keep DMR for now is the gateway we recently added, which connects D-Star to our DMR network.
Not available on the Motorola network, sorry — some people responsible for that network appear to be so scared of such innovations that they will ban a repeater from the network if such a gateway is detected.
Talk group ‘USA 1776’ could add to the appeal of DMR. It’s unclear on which network this talk group will reside, but my best guess is that it will be the Motorola network. MITCON writes:
The “USA 1776″ (English preferred) Talk Group will be distributed worldwide to DMR networks upon request. The spirit of “1776” is to continue the Amateur Radio tradition of international friendship and to push the boundaries of technology in the new frontier of digital communications.
USA 1776 is intended to be a flexible, politically neutral, unrestricted Talk Group that can be used as Push-To-Talk (PTT) or Full-Time (FT) to meet the operating requirements of a DMR Network. DMR subscribers are welcome to use 1776 as a universal meeting place to “Rag Chew” or as a jumping off point and QSY to an alternative Talk Group if desired. To add USA 1776 to your DMR Network please contact us to schedule a time for configuration & testing.
‘USA 1776′ DMR Talk Group
One of the nice things of D-Star and DMR is the ability to talk all over the world without the need of an HF rig and a bunch of big antennas. While this largely reduces a radio to a simple Internet-driven communication tool – just like Skype or other VoIP apps – it’s definitely nice to use.
There are a few problems surrounding DMR, one of which is the lack of more than two time slots. For example, if hams are using the Dutch Hytera network and occupying talk group 204 on slot 1, World Wide (which uses the same time slot) will be unavailable. Because 204-1 is a busy place, world wide QSOs are often impossible. It’s one of the reasons I thought of dumping DMR all together — I can talk to the same Dutch guys on analog while enjoying a much better quality audio.
There are reasons to keep DMR too. DMR is maturing; there are more than enough possibilities to put less pressure on the nation-wide network by going local. Now if only hams would do that…. but most don’t. Another reason to keep DMR for now is the gateway we recently added, which connects D-Star to our DMR network.
Not available on the Motorola network, sorry — some people responsible for that network appear to be so scared of such innovations that they will ban a repeater from the network if such a gateway is detected.
Talk group ‘USA 1776′ could add to the appeal of DMR. It’s unclear on which network this talk group will reside, but my best guess is that it will be the Motorola network. MITCON writes:
The “USA 1776″ (English preferred) Talk Group will be distributed worldwide to DMR networks upon request. The spirit of “1776” is to continue the Amateur Radio tradition of international friendship and to push the boundaries of technology in the new frontier of digital communications.
USA 1776 is intended to be a flexible, politically neutral, unrestricted Talk Group that can be used as Push-To-Talk (PTT) or Full-Time (FT) to meet the operating requirements of a DMR Network. DMR subscribers are welcome to use 1776 as a universal meeting place to “Rag Chew” or as a jumping off point and QSY to an alternative Talk Group if desired. To add USA 1776 to your DMR Network please contact us to schedule a time for configuration & testing.
Review Pofung (Baofeng) GT-1
I didn’t pay much attention to the GT-1 because I assumed it was just old wine in a new bottle. Time to rectify this, due to popular demand.
We all know the Baofeng BF-666S / BF-777S / BF-888S radios: 16 UHF channels, no display, low power output, a receiver which can be overloaded by snapping your fingers, but they are dirt cheap. The GT-1, co-developed by SainSonic, promises to improve on this concept by adding FM radio, a higher capacity battery and higher power output.
Look & feel
When it comes to looks, the GT-1 looks a bit more modern than its predecessors. The radio is slightly taller and less deep. All in all the GT-1 looks and feels nice. The basic concept didn’t change: 16 programmable UHF channels between 400 MHz and 470 MHz, scramble (voice inversion), a on/off/volume pot, a 16-step rotary encoder and a flashlight. Apart from emitting a steady beam of light the flashlight now offers an ‘SOS- mode: three short, three long and three short pulses.
You can order the radio with side keys in different colors: yellow, orange or green. The (of reasonable quality) manual comes in three languages: English, French and German. Nice touch.
Battery
According to the specs printed on the battery the nominal voltage is 7.4 Volts @ 1800 mAh, the same capacity as the UV-5R battery. Such a capacity would be in line with the higher power output promised on the radio label: a solid 5 Watts instead of ‘less or equal to 5 Watts’ printed on a BF-888S (which proved to be 2 Watts only).
The first hint of something being terribly wrong was the weight of the battery. It felt so light that I was afraid that it might end up at the other end of the living room if I had a nasty cough. Time to to take a closer look at things. Let’s take a look at the weight first as more cells always translates into a heavier battery. The amount of plastic used plays a role too, of course. So while this is not a 100% reliable method, it does give you an indication.
Battery weight comparison
Pofung GT-1: 47 grams
Baofeng BF-666S: 54 grams
Baofeng UV-5R: 80 grams
Anytone NSTIG-8R: 96 grams
As you can see the weight of the GT-1 and BF-666S batteries are close. The UV-5R and NSTIG-8R batteries are too, both proven to be 7.4 Volts @ 1800 mAh. The GT-1 battery seems just too light to be in the same 7.4 Volts / 1800 mAh league.
I took my multimeter and checked the GT-1 battery. Not to my surprise it only measured 4.0 Volts (freshly charged), so the nominal voltage is 3.7 Volts only, just like the BF-666S battery. The capacity will likely be the same too, somewhere between 1000 mAh and 1500 mAh.
Transmitter
After finding out that the battery might even be inferior to the one supplied with its predecessor I didn’t expect the GT-1 to be able to reach 5 Watts output at all. That proved to be correct. Two samples measured the same: between 1.5 – 2 Watts, depending on the frequency.
TX Audio
A bit brighter and slightly louder than my BF series, which is a plus.
Phase noise and harmonics
Less phase noise than the BF series. There are some unusual peaks visible, but nothing scary.
Receiver
At -126 dBm the GT-1 is sensitive enough, but that won’t help you much. It doesn’t take much of an out-of-band signal to make the radio as deaf as a post. Even the local repeater can’t be received in my city center; only if I’m about 3 kilometers away from the center the receiver comes to life.
FM Radio
By holding the upper side key while switching on the radio, the GT-1 will switch to FM radio, something the BF series don’t offer. There doesn’t appear to to be a way to tune to a preferred station though; it randomly tunes into stations it finds. This makes the feature of limited use.
RX Audio
A bit raw, just like with the BF series, but more tinny. Audio distorts quickly if you crank up the volume.
Software
The GT-1 can be programmed with the same software developed for the BF series. CHIRP works too, but lacks a few options such as switching on scramble. Changing power output from ‘High’ to ‘Low’ in the software still doesn’t work; the radio just ignores that setting.
The verdict
After being confronted with all the lies surrounding the Pofung GT-1 there’s no way I can justify a diplomatic way of saying things. The GT-1 is just old wine in a new bottle, the battery voltage / capacity is one big lie and so is the promised power output.
The receiver is still disappointing unless you live in the proverbial ‘middle of nowhere’. To make matters worse the GT-1 is more expensive than a Baofeng BF-666S / BF-777S / BF-888S.
In short: don’t buy one unless you’re a notorious masochist. Go for a UV-5R instead or, if you like/need this particular concept, buy the superior Anytone ANILE-8R.
Review Pofung (Baofeng) GT-1
I didn’t pay much attention to the GT-1 because I assumed it was just old wine in a new bottle. Time to rectify this, due to popular demand.
We all know the Baofeng BF-666S / BF-777S / BF-888S radios: 16 UHF channels, no display, low power output, a receiver which can be overloaded by snapping your fingers, but they are dirt cheap. The GT-1, co-developed by SainSonic, promises to improve on this concept by adding FM radio, a higher capacity battery and higher power output.
Look & feel
When it comes to looks, the GT-1 looks a bit more modern than its predecessors. The radio is slightly taller and less deep. All in all the GT-1 looks and feels nice. The basic concept didn’t change: 16 programmable UHF channels between 400 MHz and 470 MHz, scramble (voice inversion), a on/off/volume pot, a 16-step rotary encoder and a flashlight. Apart from emitting a steady beam of light the flashlight now offers an ‘SOS- mode: three short, three long and three short pulses.
You can order the radio with side keys in different colors: yellow, orange or green. The (of reasonable quality) manual comes in three languages: English, French and German. Nice touch.
Battery
According to the specs printed on the battery the nominal voltage is 7.4 Volts @ 1800 mAh, the same capacity as the UV-5R battery. Such a capacity would be in line with the higher power output promised on the radio label: a solid 5 Watts instead of ‘less or equal to 5 Watts’ printed on a BF-888S (which proved to be 2 Watts only).
The first hint of something being terribly wrong was the weight of the battery. It felt so light that I was afraid that it might end up at the other end of the living room if I had a nasty cough. Time to to take a closer look at things. Let’s take a look at the weight first as more cells always translates into a heavier battery. The amount of plastic used plays a role too, of course. So while this is not a 100% reliable method, it does give you an indication.
Battery weight comparison
Pofung GT-1: 47 grams
Baofeng BF-666S: 54 grams
Baofeng UV-5R: 80 grams
Anytone NSTIG-8R: 96 grams
As you can see the weight of the GT-1 and BF-666S batteries are close. The UV-5R and NSTIG-8R batteries are too, both proven to be 7.4 Volts @ 1800 mAh. The GT-1 battery seems just too light to be in the same 7.4 Volts / 1800 mAh league.
I took my multimeter and checked the GT-1 battery. Not to my surprise it only measured 4.0 Volts (freshly charged), so the nominal voltage is 3.7 Volts only, just like the BF-666S battery. The capacity will likely be the same too, somewhere between 1000 mAh and 1500 mAh.
Transmitter
After finding out that the battery might even be inferior to the one supplied with its predecessor I didn’t expect the GT-1 to be able to reach 5 Watts output at all. That proved to be correct. Two samples measured the same: between 1.5 – 2 Watts, depending on the frequency.
TX Audio
A bit brighter and slightly louder than my BF series, which is a plus.
Phase noise and harmonics
Less phase noise than the BF series. There are some unusual peaks visible, but nothing scary.
Receiver
At -126 dBm the GT-1 is sensitive enough, but that won’t help you much. It doesn’t take much of an out-of-band signal to make the radio as deaf as a post. Even the local repeater can’t be received in my city center; only if I’m about 3 kilometers away from the center the receiver comes to life.
FM Radio
By holding the upper side key while switching on the radio, the GT-1 will switch to FM radio, something the BF series don’t offer. There doesn’t appear to be a way to tune to a preferred station though; it randomly tunes into stations it finds. This makes the feature of limited use.
Edit: pressing the upper side key shortly will make the radio switch from station to station. Some in-house interference made the system fail when I tested it. The interference caused the scan to stop when encountering these false positives.
RX Audio
A bit raw, just like with the BF series, but more tinny. Audio distorts quickly if you crank up the volume.
Software
The GT-1 can be programmed with the same software developed for the BF series. CHIRP works too, but lacks a few options such as switching on scramble. Changing power output from ‘High’ to ‘Low’ in the software still doesn’t work; the radio just ignores that setting.
The verdict
After being confronted with all the lies surrounding the Pofung GT-1 there’s no way I can justify a diplomatic way of saying things. The GT-1 is just old wine in a new bottle, the battery voltage / capacity is one big lie and so is the promised power output.
The receiver is still disappointing unless you live in the proverbial ‘middle of nowhere’. To make matters worse the GT-1 is more expensive than a Baofeng BF-666S / BF-777S / BF-888S.
In short: don’t buy one unless you’re a notorious masochist. Go for a UV-5R instead or, if you like/need this particular concept, buy the superior Anytone ANILE-8R.














