Posts Tagged ‘NASA’
Vacuum Tubes – Electronics at Work: 1943 Educational Film
In the classic educational film titled “Electronics at Work,” produced by Westinghouse in 1943, viewers are introduced to the fascinating world of vacuum tubes. This film highlights the crucial role these devices played in both military and commercial sectors, including radio telecommunications, radar, and various industrial applications. The narrative suggests that vacuum tubes provided the United States with a significant advantage during World War II, particularly in enhancing communication and technology.
The Continuing Relevance of Vacuum Tubes
Despite advances in technology, vacuum tubes remain in use today for several applications, including:
– Transmitting radios
– Medical devices
– Audio amplification systems
– High-frequency applications
Understanding Vacuum Tubes
The film outlines the six basic functions of electronic tubes and illustrates how each type is employed in different industrial and military contexts.
Structure of a Vacuum Tube
A vacuum tube typically consists of two or more electrodes housed within a vacuum inside an airtight enclosure. Key features include:
– Electrode Types: Most vacuum tubes have glass envelopes, although some utilize ceramic or metal casings with insulating bases.
– Leads and Sockets: The electrodes connect to leads that pass through the envelope via an airtight seal. These leads often take the form of pins, allowing for easy replacement in a tube socket, as tubes were a common point of failure in electronic devices.
– Capacitive Design: Some tubes feature a top cap on the electrode to minimize interelectrode capacitance, enhancing high-frequency performance and maintaining safety by separating high voltages.
The Evolution of Vacuum Tubes
The earliest vacuum tubes emerged from incandescent light bulbs, which contained a heated filament sealed in an evacuated glass envelope. When heated, the filament releases electrons into the vacuum through a process known as thermionic emission.
– Electrode Functionality: A second electrode, known as the anode or plate, attracts these electrons if it holds a more positive voltage. This mechanism results in a flow of electrons from the filament (cathode) to the plate, creating an electric field due to the potential difference between them.
– Diode Function: A vacuum tube with two electrodes is termed a diode, which functions as a rectifier. Diodes allow current to flow in only one direction, converting alternating current (AC) into pulsating direct current (DC). This technology is widely used in DC power supplies and in demodulating amplitude-modulated (AM) radio signals.
Film Availability and Production Details
This film is available in the public domain under Creative Commons, and it can be accessed through the Library of Congress Prelinger Archives. The film has been edited and converted to HD quality for better viewing. Introductory and closing music is provided by Nero 10, with commercial use rights granted.
This film not only serves as an educational tool but also highlights the enduring legacy of vacuum tube technology in the realm of electronics, illustrating its significant contributions to both past and present technological advancements.
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Solar Cycle 25, and a Life-Changing Event (Part 1 of 2)
From the RAIN HamCast episode #56, 2021-XII-11 (used with permission):
When you were knee high to a grasshopper, did you undergo a game-changing experience that shaped your future career?
Here is text from the introduction:
Tomas Hood/NW7US did. Tomas has been a shortwave enthusiast since 1973. He was first licensed as a ham in 1990 at age 25.
In the mid 1990s Tomas launched the first civilian space weather propagation website, HFRadio.org, which later spawned SunSpotWatch.com. His website, NW7US has been up and running since June, 1999. Tomas has contributed to the Space Weather Propagation column in CQ magazine for over 20 years, and for The Spectrum Monitor magazine since 2014.
A product of the Pacific northwest, Tomas resides today in Fayetteville, OH. RAIN’s Hap Holly/KC9RP spoke with Tomas recently about Solar Cycle 25 and the game-changing afternoon Tomas experienced in 1973 at age 8 ( Read more about this, at his amateur radio and space weather blog: https://blog.NW7US.us/ ).
Here is the first part of the two-part interview:
Mentioned in the interview is Skylab:
From Wikipedia’s article on Skylab: Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations included an orbital workshop, a solar observatory, Earth observation, and hundreds of experiments.
Tomas was drawn into space weather as a life-long passion, by inspiration from Skylab, and from the hourly propagation bulletin from the radio station WWV.
WATCH FOR THE NEXT EPISODE, PART TWO
This video is only part one. The RAIN HamCast will conclude Hap’s conversation with Tomas in RAIN HamCast #57, scheduled for posting Christmas Day.
Hap Holly, of the infamous RAIN Report (RAIN = Radio Amateur Information Network), is now producing The RAIN HamCast. The results are both on https://therainreport.com and on the RAIN HamCast YouTube channel, https://www.youtube.com/channel/UCUbNkaUvX_lt5IiDkS9aS4g
KEEP ON HAMMING!
The RAIN Hamcast is produced and edited by Hap Holly/KC9RP; this biweekly podcast is copyright 1985-2021 RAIN, All rights reserved. RAIN programming is formatted for Amateur Radio transmission and is made available under a Creative Commons license; downloading, sharing, posting and transmission of this ham radio program via Amateur Radio in its entirety are encouraged. Your support and feedback are welcome on https://therainreport.com. Thanks for YouTube Technical Assistance from Tom Shimizu/N9JDI.
Everything Ham radio podcast Ep 93 – NASA On The Air(NOTA)
I’m sure that you have heard of NPOTA, National Parks On The Air, and SOTA, Summits On The Air, and probably even POTA, Parks On The Air, The US program for the World Wide Flora and Fauna, but have you heard of the latest event that starts on Sunday, Dec 11, 2017?
Starting at 0000 UTC time on December 11, 2017 the new year long event celebrating multiple anniversaries for the NASA program will start. It is called NOTA or NASA On The Air.
With several NASA clubs doing several special event stations of the coming year, they decided to make a year long event where you, as the end user, can contact the stations to earn points through the year. You can even gets points during other events like Winter Field Day, the ARRL Field Day and others.
Losten to my latest podcast episode where I talk with Rob Suggs about it:
Thirty Minutes of Dazzle: The Sun in UHD 4K by SDO (NASA)
Take a front-seat view of the Sun in this 30-minute ultra-high definition movie in which NASA SDO gives us a stunning look at our nearest star.
This movie provides a 30-minute window to the Sun as seen by NASA’s Solar Dynamics Observatory (SDO), which measures the irradiance of the Sun that produces the ionosphere. SDO also measures the sources of that radiation and how they evolve.
SDO’s Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 Kelvin (about 1 million degrees F.) In this wavelength it is easy to see the sun’s 25-day rotation.
The distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and the Earth orbits the sun at 67,062 miles per hour.
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. Moreover, studying our closest star is one way of learning about other stars in the galaxy. NASA’s Goddard Space Flight Center in Greenbelt, Maryland. built, operates, and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C.
Charged particles are created in our atmosphere by the intense X-rays produced by a solar flare. The solar wind, a continuous stream of plasma (charged particles), leaves the Sun and fills the solar system with charged particles and magnetic field. There are times when the Sun also releases billions of tons of plasma in what are called coronal mass ejections. When these enormous clouds of material or bright flashes of X-rays hit the Earth they change the upper atmosphere. It is changes like these that make space weather interesting.
Sit back and enjoy this half-hour 4k video of our Star! Then, share. 🙂
73 dit dit
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.
Stunning Video of the Sun Over Five Years, by SDO
Watch this video on a large screen. (It is HD). Discuss. Share.
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.
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