Podcasts about capacitance

In 1981, RCA released a new media format on the market. It was the CED -- the Capacitance Electronic Disc, and it was meant to compete with Betamax, VHS and LaserDisc. How did it do? Not so great! But I own one, so I'm doing an episode about it!See omnystudio.com/listener for privacy information.

In this episode, OMICRON voltage transformer testing experts Thomas Bischof and Felix Feustel introduce the new measurement method they developed to determine C-divider capacitance on capacitor voltage transformers (CVTs) using OMICRON's VOTANO 100 measurement system. They describe the significance of their new, patented measurement method and how it can now be automatically and reliably performed regardless of the CVT design.

Ready to level up your RF knowledge in the world of HFC plants? Our next episode is a must-watch just for you! Get pumped as our host extraordinaire, Brady Volpe, teams up with the renowned Ron Hranac for a knowledge-packed session. The presentation will cover the widespread myth of a so-called capacitance effect supposedly being The post Myth of capacitance effect appeared first on Volpe Firm.

Rob and Ryan watched and break down Season 2, Episode 15 of the Big Bang Theory: The Maternal Capacitance!**GIVE US A 5 STAR REVIEW ON APPLE PODCASTS AND BE ENTERED IN TO WIN A $100 GIFT CARD TO AMAZON! BETTER LISTEN TO THE EPISODE FOR DETAILS! https://podcasts.apple.com/us/podcast/theoretical-nonsense-the-big-bang-theory-watch-a/id162307941400:00:00 - Intro, emails, neighbor update00:11:30 - Recap begins00:16:28 - Do people hold their phone to the left ear while having analytical conversations?00:35:02 - How to greet people besides hand shaking00:45:58 - Freud's 5 Psychosexual Stages of Human Development (and why it's criticized!)00:56:44 - Those who go into the performing arts suffer from an external locust of identity? 01:13:12 -  How growing a pancreas in a gibbon is close to curing diabetes 01:29:35 - Ersatz relationships, gynophobia, and femophobia 01:38:01 - Are the Italians creating a dark matter signaal found in sodium iodide crystals?Find us everywhere at: https://linktr.ee/theoreticalnonsense~~*CLICK THE LINK TO SEE OUR IQ POINT HISTORY TOO! *~~-------------------------------------------------Welcome to Theoretical Nonsense! If you're looking for a Big Bang Theory rewatch podcast blended with How Stuff Works, this is the podcast for you!  Hang out with Rob and Ryan where they watch each episode of The Big Bang Theory and break it down scene by scene, and fact by fact, and no spoilers! Ever wonder if the random information Sheldon says is true? We do the research and find out! Is curry a natural laxative, what's the story behind going postal, are fish night lights real? Watch the show with us every other week and join in on the discussion! Email us at theoreticalnonsensepod@gmail.com and we'll read your letter to us on the show! Even if it's bad! :) If you need any artwork done for you, check out johnkimdesigns.comMusic by Alex Grohl. Find official podcast on Apple, Stitcher, and Spotify https://podcasts.apple.com/us/podcast/theoretical-nonsense-the-big-bang-theory-watch-a/id1623079414

Glen unboxes the Anang talking multi meter. And gives us a little demo of the voices. As of this podcast the $20 version is sold out but here is the link to Amazon. ANENG Pocket Multimeter Voice Broadcast Electrical Tester 4000Counts Ohm meter for AC/DC Voltage,Current,NCV,Resistance,Continuity,Capacitance,Diodes,Temperature Meansurement,Volt Meter for Automotive: Amazon.com: Tools & Home Improvement Here is a link to the $32 version. M109 Professional Smart Multimeter 4000 Counts True RMS Auto Voice Broadcast Electronic Equipment Ohm Testers Meters Tools (with Box-Red): Amazon.com: Tools & Home Improvement Don't forget to visit our YouTube channel and our website www.blindhams.com

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.12.09.519806v1?rss=1 Authors: Severin, D., Shirley, S., Kirkwood, A., Golowasch, J. Abstract: Capacitance is a property of biological membranes determined by the properties of the lipid portion of the membrane, as well as morphological features of a cell. In neurons, membrane capacitance is a determining factor of synaptic integration, action potential propagation speed and firing frequency. Besides slow changes associated with increased morphological complexity during postnatal maturation, neuron membrane capacity is largely considered a stable, non-regulated constant magnitude. Here we report that in pyramidal cells of mouse primary visual cortex the membrane capacitance changes nearly two-fold between the start and the end of a daily light cycle. The changes are large, nearly two-fold in magnitude in pyramidal cells, but do not affect cortical parvalbumin-expressing inhibitory interneurons. We discuss possible functional and practical implications as well as potential mechanisms. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Pick 'n Place machine in operation (0:05) Kapton tape inspection markers on the Pick 'n Place monitor (1:00) Problem with a reel of USB-C connectors (1:03) Capacitance conversion cheat sheet on the PnP (1:05) Set of QT Py ESP32 PCBs (1:07) https://www.adafruit.com/product/5325 https://www.adafruit.com/product/5395 https://www.adafruit.com/product/5426 Bluefruit LE Friends and Sniffers getting soldered up and qa'd (1:09) https://www.adafruit.com/product/2269 https://www.adafruit.com/product/2267 Adding more facade to the Disney building (1:52) #adafruit #manufacturing #advancedmanufacturing ----------------------------------------- Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/ -----------------------------------------

This week John and India talk festivals, bear deterrents, awesome camping destinations, and more!

Bryan describes the tricky concept of power factor and why we should care about it. He also compares power factor to a beer mug to make the topic easier to understand. Power is often represented on a sine wave, which is a curvy line that marks the state of electrical energy at different points on a circle. Power gets stronger and weaker, and it goes above and below the neutral line depending on the excess or deficit of electrons. Unity power factor refers to a power factor of 1, indicating that voltage and amperage are perfectly balanced; there is no lag. However, an inductance (a form of resistance) opposes the current and causes an imbalance between current and voltage. Power loss or quality refers to the difference between the input and output power that results.  Apparent power refers to volt-amps, which we'd traditionally consider to be the wattage; however, in an inductive load, the true or real power (wattage) accounts for that power loss and comes from volts x amps x power factor. We can imagine power factor as a mug of beer: apparent power (VA) is the entire mug, the foam is reactive power (wasted), and the beer itself is real power. The power company only charges for the real power, not the reactive power. However, a power factor closer to unity can help prevent motor windings or wires from overheating. To get closer to unity power factor, we need to make sure we have a run capacitor of the correct size. You can measure power factor with a power quality meter. Bryan also covers: Voltage and current Root mean square Inductive reactance Capacitance and how capacitors work Transformer VA ratings   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

On this episode of the Retroist Podcast, I discuss the often overlooked disc video format, Capacitance Electronic Disc or CED. This technology is dying quickly, I hope people can learn a little about it and appreciate it before it is gone completely.

Neck. Shot. Lime.Our episode discussion includes hand shaking habits, diving into multiple parent-child relationships and their issues, the LIME KISS, Bob vs. Wyatt, and more!Download hereRunning time: 1:06:03, 44.9 MB

Foundations of Amateur Radio After discussing the notion that it's not really possible to determine how your gear is performing without measuring, several people commented that in the good old days an amateur was expected to have sufficient equipment to test performance of their gear. I flippantly pointed out that once upon a time, computers ran on punch cards too. That's not to dismiss the notion of testing, but rather that times have changed. Testing equipment that was suitable in the 1980's is still available around the place, but expect to pay for it. Some of it is still relevant, some less so. Even if you do acquire suitable equipment, how do you know if what you're measuring is real? How do you know if the frequency counter that you have is accurate, how do you know if 1 Volt is 1 Volt, or 1 second is 1 second? As I've said before, measurement is the act of comparing two things. If you think that's ludicrous, consider the rulers and tape measures in your home. They all indicate the same measurement, right? Just for a laugh, pull out all the ones you can find and see what you discover. If you've not done this, you're in for a surprise. I don't want to dissuade you from getting testing equipment, far from it, but don't expect to fork out to get the equipment and call the job done. The point being that spending lots of money on gear isn't the end of the story, it's just the beginning and in my opinion it's not the place you should start. Based on community responses, ninety recommendations in all, so hardly scientific or representative, but still a good feel for the space we're playing in, the single most important piece of equipment you should get after sorting out your radio, antenna, coax, power supply, computer, software and other fun things we fill our shacks with is the Digital Multi Meter. You can spend anywhere from $10 to $500 on one, but it should be high on your list. As with the rulers, your results will vary, so be mindful of that when you go shopping. While the SWR meter and the Watt or Power meter appear regularly, they're not the next highest ranked testing gear. Mind you, most current radios have those built-in to some extent, so perhaps the numbers are somewhat distorted here. The next essential piece of equipment is some form of monitoring. Either active, passive, programmable, automated, manual, what ever. Hardware like the NanoVNA, the TinySA, even using a Software Defined Radio feature high on the list. Most of these devices either generate a signal to test against, or they rely on your radio to do the heavy lifting, depending entirely on what you're testing. An antenna analyser is among these kinds of tools. As an aside, the dummy load, either a high power one, or a more modest one, come recommended by many different people. Together with this list of monitoring equipment comes associated accessories, adaptors, patch leads, attenuators and filters. After that comes equipment such as variable power supplies, Watt meters, grid dip meters, oscilloscopes and frequency counters. I will observe that from the responses I received there was a distinct flavour to the recommendations. On the one hand there was the combination of recommending something like a station monitor, or a signal generator, an oscilloscope and a frequency counter, including things like a Bird 43 RF Watt meter. On the other hand were recommendations for spectrum analysers, NanoVNAs, SDRs and the like. It's not quite across the analogue to digital divide, but it's close. Note at this point that I'm a software guy in the process of restoring an analogue HP 606A Signal Generator from the early 1960's, so I'm not pointing the finger anywhere. There were other tools recommended too, an LCR meter, a tool that allows you to measure Inductance, Capacitance and Resistance, something you can buy in kit form if you want to get started, or similarly, can be purchased for varying amounts of money online. Speaking of money, varying amounts that is, the service monitor was on the wish list for several people. Prices between that of a new radio or a new car with varying amounts of warranty. I will make mention of a bi-directional coupler which was marked as essential by one amateur. It's a tool that allows you to sample a signal in the forward and the reflected path which comes in handy when you're trying to test and build equipment. As mentioned before, your transceiver has some of this equipment built in, or can be set-up to do some of this, so there's no need to go out and spend thousands of dollars to set-up your testing bench on day one, but the day after, I'd add it to my birthday list. No doubt that there's many and varied opinion on this. What is your essential testing equipment? I'm Onno VK6FLAB

Capacitance at Adafruit: https://www.adafruit.com/?q=capacitor&sort=BestMatch Electrolytic vs Ceramic #capacitors – why choose one over the other? #adafruit #collinslabnotes Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/ -----------------------------------------

Find capacitance at Adafruit: https://www.adafruit.com/?q=capacitor&sort=BestMatch Beyond voltage & resistance, many multimeters can handle basic capacitance as well. #adafruit #collinslabnotes Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/ -----------------------------------------

Research on psychic abilities and phenomena has been conducted for hundreds of years. Since at least the 1970s, the US has invested in ESP investigations. These perceptions are part of the human experience and can be enhanced artificially through drugs and machines or naturally through meditation and human connection. We often overlook our ability to interfere with electronics or even turn off street lamps in certain emotional states that are often associated with poltergeist activity. The body is electric and electricity can both heal and harm. It is responsible for many of these psychic abilities and phenomena and though it remains largely unseen, it is used to power our world often with detrimental effect on our health. Support this podcast

Research on psychic abilities and phenomena has been conducted for hundreds of years. Since at least the 1970s, the US has invested in ESP investigations. These perceptions are part of the human experience and can be enhanced artificially through drugs and machines or naturally through meditation and human connection. We often overlook our ability to interfere with electronics or even turn off street lamps in certain emotional states that are often associated with poltergeist activity. The body is electric and electricity can both heal and harm. It is responsible for many of these psychic abilities and phenomena and though it remains largely unseen, it is used to power our world often with detrimental effect on our health.

Plug in at your leisure and get productive, listening to our Podcasts! Also check Season 1&2 of Biology Chapters, If you like the work we do, Do Share and Support us. Happy Listening! --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app

NEC Journeyman Electrical Questions and Answers with Code References NEC - National Electrical Code is super boring. The Electrical Journeyman test is hard. Practice tests are everywhere but a Q&A style reading of questions that will be on the test is hard to find. I created this to hopefully help one person to pass their journeyman test and get their card, Nothing like this available, listen while you work, shower, drive, hike, work out. Learning without all the fluff and sales pitch garbage that so many others put out. Enjoy this content. All content brought to you by Nathan Hawkins free of charge. Pass the journeyman Electrical Test first try National Electrical Code 2020

Relay: https://amzn.to/2LX002bRelay Shield: https://amzn.to/2TCq4E5Solid State Relay: https://amzn.to/2LWRdNVMosfet: https://amzn.to/2A4fhM7Proto Pasta Capacitance Filament: https://amzn.to/2ZyLwxyAdafruit Capacitance Board: https://amzn.to/2ZBUIBa

Tim teaches Jaron about Capacitance Electronic Discs (CEDs). This was RCA's attempt at putting videos on vinyl discs, before releasing the VHS. Jaron points out how often Tim says "anyways", and we start bleeping Tim's normal words to sound like he's cussing. PATREON: http://patreon.com/jaronmyers FACEBOOK: http://facebook.com/tillnpodcast TWITTER: http://twitter.com/tillnpodcast INSTAGRAM: http://instagram.com/tillnpodcast ————————————————————————————————————————————————————— Subscribe to the show on Apple Podcasts http://bit.ly/tillnpodcastapp Listen on Spotify http://bit.ly/tillnonspotify ————————————————————————————————————————————————————— Questions or comments about an episode? podcast@jaronmyers.com 816-533-4883 ————————————————————————————————————————————————————— Follow Jaron Website: http://jaronmyers.com Instagram: http://instagram.com/jaronmyers Facebook: http://facebook.com/jaronmyerscomedy Twitter: https://twitter.com/jaronmyers YouTube: https://youtube.com/jaronmyers ————————————————————————————————————————————————————— Follow Tim Instagram: http://instagram.com/timstagram182 Twitter: https://twitter.com/timstone182 ————————————————————————————————————————————————————— Producer Alex Garnett https://www.alexgarnettaudio.com/ —————————————————————————————————————————————————————

Originally was gonna be longer, but I decided, "Eh, fine as is." 2020 Creative Commons CC Attribution Noncommercial No Derivative Works (BY-NC-ND)

This is the audio from our video here: https://youtu.be/pmUq8uK_AL8 Nerd warning! This show is probably not for first-time viewers, nor anyone looking for quick and simple answers. This stuff is deep, fundamental… and yet all grounded (pun entirely intended) in basic electronics! We are delighted to once again welcome Simon Jarrett to the studio. Simon is the man behind Kingsley Amplifiers (and pedals), based in Maple Ridge, Canada. Dan and I have been consistently blown away with Kingsley’s range of pedals and preamps, partly because of their meticulous design and build quality and partly because they are imbued with Simon’s own personal musical connection with tremendous guitar tone. We attempt to unravel some of that in this show, talking about guitar electronics basics such as input impedance, capacitance in guitar controls (low pass filter) and amp/pedal input stages (coupling capacitor/high pass filter), gain stage biasing and all those interrelated factors that have a fundamental effect on your guitar sound… long before you get into to worrying about which of the 487 Tube Screamer clones to buy. It will be well over the heads of anyone looking for quick fixes or simple answers and advice… but absolutely fascinating for anyone who has been playing and tweaking for years and not quite connecting the dots of what’s actually happening (like me, Mick here). Massive thanks to Simon and his wife Christine for taking time out of their vacation to spend time nerding at That Pedal Show. Enjoy the episode. If you dare! Pedals & stuff in this episode… • TheGigRig Three2Onehttps://www.thegigrig.com/three2one • TC Electronic PolyTune 2 MiniUK & Europe: http://bit.ly/2jKaukTUSA: http://bit.ly/2k2Gu4BAustralia: http://bit.ly/2vn6b6N • Kingsley Surf PrototypeNot out (yet?) • Ibanez TS808 Tube Screamer Keeley ModNo longer made • Kingsley Architecht PrototypeNot out (yet?) • Kingsley Squire EF86http://kingsleyamplifiers.com/products/pedals/17/ • Kingsley Constable V2http://kingsleyamplifiers.com/products/pedals/58/ • Electro-Harmonix Memory Man Deluxe 1100-TTUK & Europe: http://bit.ly/2WbQLhG • Catalinbread Topanga ReverbUK & Europe: http://bit.ly/2mj3leKAustralia: http://bit.ly/2qVOTyJ • TheGigRig G2https://www.thegigrig.com/g2 * Why do we have preferred retailer links? Find out here: http://www.thatpedalshow.com/partners Interesting bits and go-to sections…- Intro playing: 0:00- Simon lives in Canada and makes amps and pedals: 2:45- What are we doing today? 6:50- Resonant peak? 8:20- Fundamentals, harmonics and their relationship with guitar tone: 9:45- …and clipping: 12:48- Capacitance, inductance, resistance in pickups, reactance and pots: 14:30- Capacitors on tone pots in guitars: 17:50- Back to resonant peak: 19:00- Rolling down a 0.022uF cap in a Stratocaster: 20:50 (23:15)- 0.0022uF and 0.022uF caps compared: 24:30- Input impedance and why it matters: 29:10- Guitar pickups are high impedance devices: 30:30- Les Paul/Constable/input impedance: 34:43 (35:53)- Coupling caps & bottom end: 37:14 (38:30)- …and input impedance: 39:05- A treble booster is attenuated bottom and top: 39:40- Oh WOW, so THAT’S what a treble booster does. Sort of: 41:20- The effect of the volume control and treble bleeds: 44:40 (48:20)- Mick’s massive generalisation: 55:27- Considerations for the first gain stage of the amp: 57:05- Bias in preamp valves: 58:50 (1:03:30)- Simon plays us out (1:11:37) Guitars in this episode:• Fender American Vintage ’62 Stratocaster – Mick’s video at http://bit.ly/2cQv3yT• Gibson Custom 1958 Les Paul Standard – watch Dan’s video at http://bit.ly/2dbwbvS• Gibson Memphis 1958 ES-335 - no video yet Amps in this episode• Two Rock Classic Reverb Signature with 212 cabinet / TR65B speakers• Fryette Power Station with Two Rock 112 cabinet / WGS12L speaker We hope you enjoy this episode. Please subscribe to our channel. You can buy TPS merch to support our efforts https://www.thatpedalshowstore.com We are on Patreon – crowdfunding for creativeshttps://www.patreon.com/ThatPedalShow Please visit our preferred retailers!UK & Europe: Andertons Music http://bit.ly/2cRvIvtUSA: Riff City Guitar & Music Company http://bit.ly/2cyOYjDAustralia: Pedal Empire http://bit.ly/2mWmJQf

Listen in to Judy Warner and guest John Andresakis from DowDupont and learn about embedded resistance materials. There are several benefits that make this a beneficial technology. Did you know that you can take up to 90% of your decoupling caps off the surface of the board, while improving reliability and reducing inductance? Learn about several design considerations for using embedded capacitors and build on the knowledge of experts like Rick Hartley and Eric Bogatin who both addressed inductance in their AltiumLive San Diego keynotes. Watch the video, click HERE. Show Highlights: Senior Technical Marketing Leader - Interconnect Solutions at DowDupont; 30 years experience mostly on the materials side and now at DowDupont, soon to be the new Dupont. Embedded capacitance -cross connections with: Rick Hartley's keynote at Altiumlive (inductance) and Eric Bogatin's keynote as well This reduces inductance Film based materials now allow embedded capacitor layers to be 1 mil or below with excellent yields People were practicing some form of this 30+ years ago, but according to patents 25 years or so. There used to be material concerns, but with the advanced materials i.e. improvements in technology more is possible. What manufacturers are providing this service? Most of them! It's like a version of a rigid flex, without the flex part sticking out. This isn’t a very hard thing to implement, it wouldn’t be difficult for the manufacturer to get up to speed on this. The things involved are not difficult to learn. Learn more at IPC APEX - stop by DowDuPont and Insulectro - booth 624   Links and Resources: IPC Standard: 2316 Design Guide for Embedded Passive Device Printed Boards DuPont Interra HK04J Planar Capacitor Laminate IPC Standard: 4821 for embedded passive devices Rick Hartley on the Importance of PC Board Stack-up at AltiumLive Eric Bogatin on The Value of the White Space at AltiumLive

This episode focuses on Electromagnetism and the dynamo effect. It also covers Capacitance and Capacitors, and Inductance and inductors. These principles are the basis of many electrical devices and filters used in clinical practice. If you have any questions, comments or requests, please contact me at questions@planaprimary.co.uk You can find all our episodes online at planaprimary.co.uk

Episode 22 of our podcast Hard Questions with Duncan Mckay and Bronson Cornilles. Join us for some podcasting and comedy. If you have questions or comments write to us at hardquestionpodcast@gmail.com or at instagram @hqthepodcast.

This conversation reflects a discussion at the Perioperative Quality Inititative (POQI). It originally ran under the title, "Intervascular volume and fluid responsiveness" but, as this conversation explains, it was renamed "Fluid Responsiveness and venous capacitance". With a genuinely multidisciplinary approach on display here this piece gives you a glimpse at the inner workings of the POQI process. How does macro circulation interlock with micro circulation and cellular function? How do people on the ground measure stroke volumes? What do you do when passive leg raising is not appropriate? How do we address hypovolemia? How do you define fluid responsiveness at the bedside? Presented by Desiree Chappell and Mike Grocott with their guests David Kaufman Associate Professor, Director, Medical Intensive Care Unit at NYU School of Medicine, NYU-Langone Medical Center and Dr Greg Martin Director, Research Network, GaCTSA; Director, Predictive Health Institute; Research Director, Emory Critical Care Center.

This conversation reflects a discussion had at the Perioperative Quality Inititative (POQI). It originally ran under the title, "Intervascular volume and fluid responsiveness" but, as this conversation explains, it was renamed "Fluid Responsiveness and venous capacitance". With a genuinely multidisciplinary approach on display here this piece gives you a glimpse at the inner workings of the POQI process. How does macro circulation interlock with micro circulation and cellular function? How do people on the ground measure stroke volumes? What do you do when passive leg raising is not appropriate? How do we address hypovolemia? How do you define fluid responsiveness at the bedside? Presented by Desiree Chappell and Mike Grocott with their guests David Kaufman Associate Professor, Director, Medical Intensive Care Unit at NYU School of Medicine, NYU-Langone Medical Center and Dr Greg Martin Director, Research Network, GaCTSA; Director, Predictive Health Institute; Research Director, Emory Critical Care Center.

Capacitance is defined in the context of an arrangement of parallel plates. The electric field energy per unit volume is also derived.

What are microprocessors and how have they changed?

Have you ever wondered why batteries sometimes need to be inserted in alternating directions?

Do you know how your touch screen works?

Foundations of Amateur Radio When you use your trusty multi-meter to measure resistance across a 50 Ohm resistor, it shows 50 Ohm, but when you use it across a piece of 50 Ohm coax, you see either infinity, or 0. Similarly, when you measure across a folded-dipole, you see 0, not 300 Ohm. Does this mean that a 50 Ohm resistor is somehow different than a 50 Ohm piece of coax and why is the feed-point impedance of a folded dipole 300 Ohm, when your multi-meter clearly says it's 0? Does this mean that there are two types of Ohm? Today I'm going to explain why this is and what's going on. Yesterday I started reading up on the subject and every single explanation I came across went into deep ju-ju with scary maths, using complex and imaginary numbers. I did a bit of that in my dark past, but none of that is needed to understand what's happening. As you know, there is such a thing as Direct Current or DC - we use it with batteries and little power supplies, in simple circuits and all manner of day-to-day activities. There is another world that we as amateurs use, the world of Alternating Current or AC. In house-hold wiring we use 50 or 60 Hertz and different voltages depending on where on the globe we are. In radio terms we use it for our transmissions, on HF at several Mega Hertz and beyond. These two different worlds, the DC and AC world don't appear to have anything in common. Here's the kicker though, they are the same thing. Yup. DC and AC are the same thing. What? Yup. I'm not making this up. As you might recall, if you look at an AC voltage, it goes from plus to minus and back again. A 50 Hertz alternating current does this swap 50 times per second. When you're rag-chewing on 40m, or 7 MHz, it happens 7 million times a second. From plus to minus and back, 7 million times. Clearly there has to be some impact on this massive level of activity. Think of direct current as an alternating current with a frequency of 0 Hertz, that is, over time, DC doesn't change. So, DC is a short cut for saying AC at 0 Hertz. If you understand that explanation, then some really cool stuff starts to happen. Before I get to the cool stuff, you might recall Ohm's Law, commonly expressed as: "Given a current and a resistance, we can determine a voltage". Said in another way, the resistance of a circuit is related to the voltage and the current in the circuit. Now, in this simple form of Ohm's Law, the voltage doesn't change from plus to minus and back again. That is, over time, there is no change. Now if you start doing funky stuff with your voltage, like change it from plus to minus and back again, an additional type of resistance comes into play, called reactance. This reactance is the part that is affected by voltage change over time. So if you swap the voltage from plus to minus and back again a million times a second, the reactance has a big part to play. In short, there are two types of resistance, one that is independent of time, called resistance, and one that's dependent on time, called reactance. Both of these, resistance and reactance, happen within a circuit. If the voltage doesn't change over time, then the reactance part is zero and similarly there are circumstances where you can have a resistance of zero but have a reactance that's not - one example is a folded dipole. Now, if you combine the resistance and reactance, you get something called impedance. Now you have all the bits. Resistance is expressed in Ohm, Impedance is expressed in Ohm, and thus Reactance is also expressed in Ohm. If we look at our folded dipole with a feed-point impedance of 300 Ohm, you now know that this 300 Ohm comes from a resistance of 0 Ohm and a reactance of 300 Ohm at the resonant frequency, which is why your trusty multi-meter shows it as 0, since the voltage it uses to measure is alternating at 0 Hertz, which is not the resonant frequency of this antenna. Before I go, the rabbit hole goes deeper. Reactance itself is made up of Capacitance and Inductance, which each deal with the reactance in a capacitor and an inductor, but I'll leave that for another day. So, next time someone tells you that the feed-point impedance of your folded dipole is 300 Ohm, you'll now understand why your multi-meter says it's 0. I'm Onno VK6FLAB.

On this month's Vintage Rebellion Podcast it's UK meets US as Chivecast host Stephen Danley joins the Rebellion to talk Focus Collecting, Chivecast and his Collection of Capacitance amongst many other things, whilst Grant welcomes Cathy Kendrick to the show on this months oddballs to discuss Star Wars Trading Cards. On this months Newest Acquisitions Jez discusses item's purchased by the community over the last month including ESB 18 back Meccano Boba Fett, ATL Interceptor and an exciting discovery surrounding a 15" Darth Vader.  As well as many other items, Marco Jay joins the NA to chat about his Lily Ledy Boxed Snow Speeder that he's recently acquired. As well as all this Pete picks through the highlights of the recent Vectis Auction and Rich chats Mailer Mysteries, 12 inches and Fett rockets in Rebel Briefings. All this plus much more on the Vintage Rebellion, enjoy the show!!!

Steve and Skye spring back into form in this month's podcast featuring the Rebel Commando. We talk about the archive updates, share some info about new foci and invterview James Gallo about the mystery and history of Kleb Zellock. Plus, we teach you how to "Steve."

We find out why touch sensitive switches are sensitive to skin, soap and potato but not everything else? Plus we ask how do drinks & exercise affect the taste of your chewing gum? Like this podcast? Please help us by supporting the Naked Scientists

What use is an F-call? You gotta love this hobby. A fellow amateur mentioned the notion of a Magnetic Loop antenna and now, several enjoyable hours later, I've been hunting and reading, learning and imagining what you might do with one of these contraptions. If you're unfamiliar with the concept, imagine an antenna that is small, efficient, simple to make and easy to lug around. Something that is especially interesting to me, since I'm getting a little worn out with putting up my 12m squid-pole for short outings. It's fine for a setup that's going to be there for a day, but I'm beginning to wonder if I couldn't improve on the antenna solution I've used to date. The build concept is pretty simple, a 1/10th wave-length circle with a smaller inner circle loop. Physically, there's lots of funky stuff happening, Magnetism, Capacitance and Resistance, all combining to make an amazing antenna - the full explanation is beyond a quick discussion, but excellent information is available. If you spend 20 minutes online with your favourite search engine, you'll come across many and varied versions of this and each design shows a little about the builder, from 40m to 10m, even 2m and 70cm versions of this exist and are simple to make. I can imagine putting one of these in my boot, or sticking it in the roof of my house, or putting it on a simple tri-pod during a field day outing, everything you'd like in an antenna. What makes me excited about all this is that the skill level involved in making a magnetic loop antenna is not beyond my two left hands - although I'll admit that I still have to actually build one, it's something that any amateur can construct, whether you're new at this, or not. Magnetic Loops, look into it. I'm Onno VK6FLAB

Lecture begins with a discussion of electric potential distribution in conductors. Image charges are introduced and exploited. Capacitance is explained in greater detail and illustrated using the parallel plate capacitor. The energy stored in the electric field is derived. The forces acting on an electric current flowing through a conducting wire are examined. The RC circuits and its energetics are discussed. The EMF due to a battery is explained.

1. Tony Lionni - Out of Sight 2. Sean McCabe & Stephanie Cooke - Just A Little Bit 3. Demarkus Lewis - Do You Really Know 4. Castillo & Face fea. Jennifer Perryman - Love's Wine 5. Stranger Danger - Chuggy Lovebottoms 6. Angel-A - Yellow Lounge 7. Marie Joly - Loving U 8. Lem Springsteen - New Beginning 9. Rasmus Faber feat. Dyanna Fearon - Yes 10. King Britt Presents Scuba Feat - Our Time 11. N'dinga Gaba feat. Scotty P. - Queen 12. Fred Everything feat. Wayne Tennant - Mercyless 13. D-Reflection feat. Christa - Wave Of Love 14. Dennis Ferrer - The Red Room 15. Yazoo - Situation 16. Pete Dafeet - In Flux

This course explores electromagnetic phenomena in modern applications, including wireless and optical communications, circuits, computer interconnects and peripherals, microwave communications and radar, antennas, sensors, micro-electromechanical systems, and power generation and transmission. Fundamentals include quasistatic and dynamic solutions to Maxwell's equations; waves, radiation, and diffraction; coupling to media and structures; guided waves; resonance; acoustic analogs; and forces, power, and energy.