The Society of Amateur Radio Astronomers (SARA) is an international non-profit organization. The society provides a collaborative environment for radio astronomers at all levels. The members have developed radio telescopes and have detected galactic hydrogen, masers, pulsars and even fast radio bursts. The society holds two online meetings a month. One discusses everything technical about building and maintaining radio telescopes. The second shows practical observations and techniques to observe with various radio telescopes. The society holds two world-wide conferences per year where members brief the latest in radio astronomy design and builds. The society, also publishes the journal Radio Astronomy, with an issue every 2 months. If you are interested in radio astronomy visit the SARA website at radio-astronomy.org
Beautiful presentation, thank you so much for sharing. I am 44 year old husband and father of 2 small children, currently working as a software engineer, but am a trained aeronautical engineer with 4 years of work experience in the aircraft maintenance industry. I have been a licensed ham since 2013. and am very intellectually curiuos and interested in all kinds of technical stuff. The thing you mentioned about not having enough Time is very true unfortunately. Some of these pursuits and hobbies require a lot energy and attention, something i currently cannot afford, so i have to sit on the sidelines and wait for the kids to grow up. My current hobby is deep sky and landscape astrophotography, and i have some decent results, but i would label them as more "incidental" rather than deliberate, however, i am still enjoying it very much, despite the sleep deprivation and all the consequent issues 😅 I am a member od SARA as well, and have been lurking in the group for a while now, there are great many resources available with the membership and i enjoy reading all the discussions very much. I don't have anything to contribute so i stay silent, hopefully when time allows, i will be more active and maybe take on a project, like the Radio JOVE or something along those lines. Thank you again for a great presentation, i enjoyed it very much! 73 de 9A5ELO 👋🇭🇷
Hey!! Thank you very much for this post!! Would you be able to share the basic settings used on SDR# that weren't shown in the video? I really appreciate the IF Average settings rundown and tutorial - I am not sure what is best for the SDR# settings such as Demodulation mode / Gain / Filter (I would assume that raw is the appropriate demodulation, of course, but please if you have any advice on the SDR# settings I would be extremely grateful!)
At 40:42 someone on the Zoom call, turns on their screen-sharing and logs on as GBO Guest Probably there at the Green Bank Conference site. Maybe getting ready for the next talk. You know who you are!
Jerry, I suggest you consider building one of the Faraday Fabric lined Photo Umbrella Antennas. Their performance is excellent and are easy to fabricate Regards, Alex ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ymclkNnCeCc.html
great presentation I've been wanting to learn more about radio astronomy and excited to see there's a group of folks out there wanting to learn and share
I'm also a radio amateur but with no experience of radio astronomy. Done some Exoplanet data processing but just using MicroObservatory data. Just stumbled across your excellent presentation but any hints on where to do some beginners reading on the subject ?
Interesting. I have been intending to spend time involved in radio astronomy which is essentially what's being demostrated here & hope to with my RS 918 this spring. I am curious regarding your loop receiving antenna and if you could give me a little abstract of what its configuration is including transformer at the feed point I'd appreciate that. Thanks, Kc2wvb
Faraday Fabric : I have used Rejopfad Faraday Fabric Nickel Copper Faraday Cloth Kit, 44 x 39Inch Conductive Material + Faraday Tape(65FT x 0.5Inch) ( Amazon ) Alex
@@PahooKatawah idk what they are claiming to measure. Most sci projects are dark psyops anyways. Nobody who is not inside knows what is going on. For you to 7nderstand. I am moderately enough electrosensitive. Each time they say it a sunburst, it happens to be TSÖRN experiment or hahhaha-RP experiment. Tsörn is especially brutal.. Decifer names your self. The need for me to hide the names should tell you smth.
But better guestion, how much of the "sapce weather" is actually man made. A lot, is my guess. A lot. All I see is excuses so that they/them/reps can keep zapping us with F|AART antennas
Hai amateurs. Any known home made shield for humans? Currently constant C class solar x-flare. Tin house? :) Nasty stuff to be extremely sensitive. Others are too, the are just not aware. And they are not buying it. So trick i used, i say i'm psychic and i know when they felt bad. :D "omg, yes" "evil souls... I see dark energy... Here is space weather map. You are so gullable."
Hi Don, in doing a bit of research, there IS an advantage to Circular over Square Comparison between a rectangular patch antenna and a circu- lar patch antenna using the simulation results obtained from CST Microwave studio has been carried out. Both the antenna configurations show quite good results on perspectives of re- turn loss, VSWR, gain and radiation efficiency, for Bluetooth band applications. However, from the perspective of return loss and gain the rectangular patch configuration shows better performance, while the circular patch configuration shows better results on bandwidth, radiation pattern,Lower Side Lobe levels. ( example of 2.45GHz Antennas ) Parameter Rectangular Circular Return Loss 28.28 dB 22.03 dB Bandwidth 24 MHz 27 MHz Directivity 7.267 dBi 7.027 dBi HPBW 72.2 deg 77.7 deg Side Lobe -10.5 dB -19.6 dB Gain 7.119 dB 6.968 dB Radiation Efficiency 97% 98% Total Efficiency 96% 97% www.ijser.org/researchpaper/A-Comparative-Study-of-Rectangular-and-Circular-Microstrip-Fed-Patch.pdf
Thanks, Alex, that was useful. The differences seem small compared to the cost of manufacturing for those who are budget conscious. I'm considering designs for 21cm hydrogen emissions, so bandwidth is not terribly important to me. The design I have been considering is a turnstile antenna as the driven element with director and reflectors being 'X' shaped and aligned with the crossed dipoles of the turnstile. I'm still figuring out how to use 4NEC2 to model it, so I don't have any predictions yet. Ultimately, I want to construct an array of 4 of these.
Don, its not band-width but Side Lobe Suppression that is the significant difference. What is the goal of having 4 antennas ? How do you wire an array ? Each should have a closely coupled LNA.
H_Line reception is not like satellite signals: With a point source, the smaller the beam width, the greater the signal, but the same will reduce H1 signals. For hydrogen line data, a narrowing beam must be accompanied by a larger antenna capture area ( big dish ) .
Thanks for the effort. In the equations at 41:40, did we assume that the mass inside radius R is increasing linearly until R0? More mass density near the center makes sense but i couldnt see any reason for linearity at first glance.
Yagi Antenna Theory " Words of the Week " Slow Wave Structures Artificial Dielectrics lea.hamradio.si/~s53mv/cigar/sws.html Cigar Antenna History lea.hamradio.si/~s53mv/cigar/cigar.html Cigar Antenna Design lea.hamradio.si/~s53mv/cigar/design.html Cheers, Alex
Very interesting for me being an RF engineer. BTW, I had some investigations on a loop antenna with a small bandwidth, which could possibly further improve selectivity and interference resilience.
An excellent lecture on amateur astronomy. I found that my second viewing to be much more valuable than the first, as the new concepts (and math) started sinking in. As an amateur radio operator and former broadcast radio and TV engineer, allow me to expand on the motivations of many amateur astronomers. I started out as a young child as a nighttime MW-SW listener. After a while one tends to seek out more and more distant stations, referred to as "DX." In the process, antennas are experimented with, as well as receivers. Attention is paid to the ionosphere, solar activity, and RF interference. Many people experiment with QRP, or low power transmitters. There are many low power beacons out there from VLF, HF, VHF and satellites that have calibrated powers and distances. The real DX is in outer space. It is also a step up in technology and degree of challenge. Listening to a source millions of light years away is a bit more of an accomplishment than listening to one a few thousand miles away. On the subject of meteors, I believe that the radio observations are used as an indicator for optical observations. In my experience, meteor storm prediction is very similar to weather predictions. Not exactly perfect. However, using radio to detect meteor storms is real time with high precision, makes the effort to go outside on a cold night much more productive. Great lecture! Looking forward to seeing more in the future.
This is an excellent video presentation about Radio Astronomy. It is, as Jack Webb used to say "Just the Facts." It should be the template for further video presentations, as we are in a universe of information noise, and this is all information signal. Well done Sirs.
Regarding, Nathan's extended WiFi dish, drift through the Long dimension for min beam width. Antenna Beam Width measurement Run a drift scan through the Sun, record the max ampl every 10 mins or so, for +- 1.5 hours and plot Tme vs Power ( or dB ) in Excel .. The - 3dB ( half power ) points = the Beam_Width 1 hour = 15 degrees
Thank you for bringing this on youtube. One explanation for the question posed @28:34 could be that the 60-80 degree on the Galactic plane, corresponds to the hydrogen clouds in the Cygnus constellation. This region is rich in hydrogen clouds especially around Cygnus-X region. The region around star Sadr up to Deneb is also rich in HII. Of course this is different from the neutral Hydrogen used for the 21 cm measurement. Gal degrees around 140 corresponds to the constellation of Perseus and could be from the Perseus arm of the MW.
Hydrogen line observations: From frugal to advanced Part 4: Observation Results with Different Antennas Wolfgang Herrmann and the Astropeiler "Hydrogen Team astropeiler.de/wp-content/uploads/2020/01/Hydrogen_4.pdf
To measure the one way speed of light depends on how accurately time can be measured. Setup two stations with synchronized atomic clocks sending pulses of light to each other at known times. Both stations should see the same speed of light within the accuracy of the atomic clocks.
I am thinking that on the large space that encompasses the whole compound that there may some issues with the ground. The soil resistivity wont be the same across such a large area. Under all the terminals I have been a part of, there is a robust ground grid under the dish. I am a power guy though that just plays a satcomer on TV 😅.
It may well be that we need to put a ground grid under each antenna. Not only does the soil vary from place to place across the compound, but the resistivity varies depending on environmental factors such as how recently it rained. Further, this system is intended to be used in a variety of locations including across the entire US. So, the more the system can be made the same, the more easily it can be incorporated into a Very Long Baseline Interferometry system.
Have you tried replacing the RF switch with a directional coupler? You can get a better than 0.2dB insertion loss. Also, it's hard to measure low NF with this method. The uncertainty in your measurement could be more than your measurement itself.
