Foundations of Amateur Radio In the analogue world you throw up an antenna, turn on your radio, tune to a station and sound comes out. Aside from propagation restrictions, you don't particularly care when you do this. In contrast, if you fire up a WSPR or Weak Signal Propagation Reporter, each transmission lasts 110.6 seconds, every 120 seconds, starting on the even minute. An FT8 signal takes 12.6 seconds within a 15 second window. In other words, to use WSPR or FT8 you need to both transmit and receive at the right time for this to work. You don't need to go to modern modes to get the idea that time matters. Listening to any CW signal will give you an idea that time and timing is important. To give you a sense of what I mean, if you turn on your radio in the middle of a dah, in the middle of a letter, you're likely to hear the wrong symbol, perhaps decoding the partial dah as a dit and missing the first part, hearing a partial letter Q, dah dah dit dah as a dit dit dah, the letter U, and that is completely ignoring inter letter and inter word spacing. The point being that time matters for radio signals. So, if we're going to build a system that can handle radio signals inside a computer, we'll need to deal with time. Decoding is one thing, but what if you want to compare two radio signals from two different antennas? You can build a direction finding tool consisting of multiple antennas that can determine the direction of a signal by calculating the difference in time between when a signal arrived at one antenna and when it arrived at another. Of course, the distance between each antenna matters, so we'd need to deal with time in such a way that we can actually measure this. RF travels about 30 centimetres in a nanosecond. If that's not enough, what happens if you're digitising an analogue signal and sending it across the network to be processed? Not only do you need to track if information arrived at its destination or was lost in transit, if you're combining multiple signals, you'll also need to know when the information was captured. Which brings us to something entirely different and perhaps surprising. If I say "now", that moment is not the same for everybody on the planet. You might be listening to this on the train to work, your local repeater, on YouTube, or reading it on social media or in your email. Even me writing the word and reading it out loud are two different times. In other words, agreeing on time is not obvious. We could all look at the clock and share the information, but is that accurate enough? Do we tell each other how many seconds past midnight UTC, or do we need to know half or tenths of seconds? To use WSPR and FT8 it's generally enough to use the NTP or Network Time Protocol. It can be as accurate as 1 millisecond, but is that enough? To give you a sense of how precise we might need to be, a HF signal takes about 66 milliseconds to travel halfway around the globe. A mobile phone tower signal travels 6 kilometres in about 0.02 milliseconds, so NTP isn't really precise enough for what we might need. If you've played with a GPS, you might know that you can use it to determine when "now" is. It's theoretically capable of a 14 nanosecond accuracy, but by the time you actually use it, it's more like 100 nanoseconds. There's a million nanoseconds in a millisecond and a billion nanoseconds in a second. If you were to store nanoseconds as a 64-bit unsigned number, you could count between now and just over 584 years from now. Something else to consider. If you had two analogue to digital converters and you wanted to synchronise them, 1 nanosecond would allow you to get two 1 GHz signals to start at the same time, providing that you knew what time it was to that level of accuracy. If you're keen, look up maser. Before you point out that this means we'd be limited to anything below the 23cm band at 1.2 GHz, I'd like to mention that this is about representing all of it, 0 Hz to 1 GHz as one chunk of spectrum at the same time. In reality, you're much more likely to only want part of that, not to mention that we'd need to transport and process all that data as well. Which brings us to bandwidth considerations, but that's a conversation for another time. Credit to Nick VA3NNW, Kent AC1HJ, Dave VK6KV and Randall VK6WR for their thoughts and explanations. Any mistakes are all mine, feel free to point them out. I'm Onno VK6FLAB

The Moon has always sparked human curiosity. It governs the tides and biological rhythms. It’s inspired myths and stories. It’s inspired us to reach out and explore it. And it's certainly inspired CrowdScience listeners, who have sent us a host of questions about it. And in a special lunar-themed episode we’ve brought together a panel of astronomers and planetary scientists to help answer them. What would life be like if there was no Moon? Would there even be life? Or what if we had two moons? Are the Moon and Earth equally battered by meteors? What would happen if an asteroid collided with the Moon? And could the Moon ever escape Earth’s gravity? Anand Jagatia is joined by Prof Sara Russell, Head of the Planetary Materials Group at the Natural History Museum in London; Prof Neil Comins from the University of Maine, author of the book What if the Moon didn’t Exist?; and Prof Katarina Miljkovic from Curtin University in Perth, Australia. Presenter: Anand Jagatia Producer: Jeremy Grange Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Andrew Garratt(Photo: Landscape with the rising of the full moon during the golden hour Credit: Jose A. Bernat Bacete via Getty Images)

From going months without sleep, to keeping their offspring safe in their stomachs, and even selfless mama’s sacrificing themselves to feed greedy offspring, here are some of the best animal parents on the planet.Advertising Inquiries: https://redcircle.com/brandsPrivacy & Opt-Out: https://redcircle.com/privacy

HBO, VHS tapes, and unfinished business - and Oliver!If you're seeing this, please leave us a review!

With ample renewable resources, several African markets are tipped as key suppliers of green hydrogen for European industry. In this episode of Energy Evolution, hydrogen analyst Oghosa Erhahon and clean energy investor Kevin Anderson lay out which regions have the biggest potential, which constraints need to be tackled and how to ensure investments benefit local stakeholders. Beyond the export potential, markets in Africa may also develop significant local off-take for green hydrogen and its derivatives, the experts tell correspondent Camilla Naschert.  Subscribe to Energy Evolution to stay current on the energy transition and its implications.

In my family, we always choose a Christmas tree with a top branch that’s long enough to support the cardboard angel our daughter made twenty years ago.

Celeste Bello, MD, Moffitt Cancer Center, Tampa, FL Recorded on November 21, 2024 Celeste Bello, MD Senior Member, Department of Malignant Hematology Moffitt Cancer Center Tampa, FL Join us as we dive into bispecific antibodies with Dr. Celeste Bello from Moffitt Cancer Center, exploring their mechanisms of action, current indications in lymphoma, and strategies for patient selection and administration. Dr. Bello also discusses side effects, management strategies, and emerging trends in bispecific therapies. Tune in today to learn more!

This week, Wes and Shawn begin their look back at the 10 biggest space news stories of 2024Become a supporter of this podcast: https://www.spreaker.com/podcast/made-of-stars--4746260/support.

In this exciting episode of Save it for the Blind, hosts Jeff Smith and Carson Odegard dive into the heart of the waterfowl season with a mid-season recap that's sure to resonate with hunters and enthusiasts alike. They are joined by two legendary guides, Casey Stafford of CICC Outdoor Adventures and Jason Adversalo of Fowl Pursuer Outdoor Adventures, to unpack the season's highs, lows, and everything in between.The conversation explores how recent storms have shaped migration patterns, the challenges and rewards of guiding during a dynamic season, and must-know tips for hitting draw deadlines. With insider knowledge, personal anecdotes, and actionable advice, this episode offers a rare glimpse into the minds of two of the most respected names in the field. Whether you're in the marsh or gearing up for your next hunt, this episode is packed with valuable insights and stories you won't want to miss.Tune in, take notes, and get inspired for the rest of the season!

There's a quote attributed to Albert Einstein, "sit with a pretty girl for an hour and it feels like a minute; sit on a hot stove for a minute and it feels like many hours. That's relativity." There's no evidence he actually said this, but that didn't stop Julian from turning up the heat on his question. Meanwhile, Trace took the DNA from all his cells and strung it together end-to-end. How long do you think that strand would be? What if we took all the DNA from ALL the LIFE on EARTH?! There's a lot of life here!QUESTIONSJulian: "What part of the human body is the most heat tolerant" from AnonymousTrace: "If you stitched together all the DNA on Earth… how long would it be?” from MikeDo you have an absurd question? Maybe it's silly idea you had, a shower thought about the nature of reality, or a ridiculous musing about your favorite food? If you want an answer, no matter the question, tell us!HOW TO ASK A QUESTION🖥️ Submit on our website: thatsabsurdshow.com/ask☎️ Leave a voicemail: (302) TAPE-SHO [+1-302-827-3746‬]📬 E-mail questions to hello at thatsabsurdshow.comIf we use your question we’ll give you a shout out in the episode.WANT MORE US? SUPPORT THE SHOW!Want to support us and other indie creators? Join Nebula go.nebula.tv/thatsabsurdshowWant to help decide which questions we answer? Join our patreon patreon.com/thatsabsurdshowSOCIALS[[ FOLLOW OUR SHOW ]]Instagram: @ThatsAbsurdShowThreads: @ThatsAbsurdShow[[ JULIAN ]]Instagram: @HuggetoutThreads: @HuggetoutX (formerly, Twitter): @Huggetout[[ TRACE ]]Instagram: @tracedominguezYouTube: @tracedominguezThreads: @tracedominguezBlueSky: @tracedominguezX (formerly, Twitter): @tracedominguezAnd don’t sleep on ThatsAbsurdShow.com. There you can browse images and videos we find during our research and listen to every episode of the show.CREDITSThis episode of That's Absurd Please Elaborate was written by Trace Dominguez and Julian Huguet, edited by Kyle Sisk, and produced by all three of us.Theme Music by Epidemic Sound; learn more here: http://nebula.tv/epidemicThanks for listening to That's Absurd Please Elaborate. We appreciate you!See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.