Podcasts about 6db

「最大風速25m/秒のパワフルな風を奏でるダイソン初のハンディファン「Dyson HushJet Mini Coolファン」」　ダイソンは、同社初のポータブルハンディファン「Dyson HushJet Mini Cool ファン」を発表。2026年5月7日よりダイソン公式オンラインストアで先行販売を開始し、5月20日より家電量販店などで順次販売をスタートする。価格はオープン。最長6時間使えるバッテリーを搭載！本製品は、夏のアクティブなライフスタイルのために設計された多機能なファン。重量はわずか212gとスマートフォンほどの軽さで、最長6時間使えるバッテリーを搭載。昼夜を問わず、どんな場所でも涼しく快適に過ごすことができる。さらに、1分間に最大65,000回転するブラシレスDCモーターにより、最大風速25m/秒ものパワフルな風を実現。5段階の風量調節に加えて、さらに強力なブーストモードも搭載しており、仕事中や移動中のやさしい風から、猛暑時に頼れるパワフルな風まで、どんな環境でも最適な涼しさにカスタマイズできる。なお、製品には、ネックストラップ、充電スタンド、USB‑C充電用ケーブル、トラベルポーチが同梱。このほか、別売りアクセサリーとして、ベビーカーのハンドルなどに取り付けられるユニバーサルマウントや、バッグのストラップやジャケットにしっかりと固定できるグリップクリップなども展開する。■製品概要製品名：Dyson HushJet Mini Coolファンカラー：インク/コバルト、ストーン/ブラッシュ、カーネリアン/スカイサイズ：幅38mm×奥行き38mm×高さ180mm本体質量：212g運転時間：最長6時間（風量1の場合）バッテリー容量：5,000mAh充電時間：約3時間最大風速：25m/秒（ブーストモードの場合）風量設定：5段階の風量調節+ブーストモード運転音：最小48.6dB、最大71.4dB価格：オープン価格正式発売日：2026年5月20日関連情報https://www.dyson.co.jp/ja構成／立原尚子

Foundations of Amateur Radio The other day fellow amateur Randall VK6WR raised an interesting question. Using his HP 8920A RF Communications Test Set, which you might recall from our adventures in measuring radio harmonic power in 2023, that report is on my Github repository, but I digress, Randall wondered if the signal strength he was seeing on several radios were the same and discovered that in fact they were not. It made Randall ask who set the standard and following on from that, what does this look like in the real world? In 2014, episode 149 of the series "What use is an f-call?", I published an article titled "The simple S-unit". In it I referred to a standard for S-units defined in 1981. Unfortunately, I didn't provide any references, so, armed with more than a decade extra experience, Randall encouraged me to investigate. Twenty seconds into my search, I discovered IARU Region 1 Technical Recommendation R.1, which has four statements related to the topic at hand. Under the title "STANDARDISATION OF S-METER READINGS" it states that: 1. One S-unit corresponds to a signal level difference of 6 dB, 2. On the bands below 30 MHz a meter deviation of S-9 corresponds to an available power of -73 dBm from a continuous wave signal generator connected to the receiver input terminals, 3. On the bands above 144 MHz this available power shall be -93 dBm, 4. The metering system shall be based on quasi-peak detection with an attack time of 10 msec +/- 2 msec and a decay time constant of at least 500 msec. So. Job done, right? Yeah, nah, not so much. The web page I quoted from is linked from the Wikipedia S-meter entry and was archived in 2005 and at the time existed on a Swedish domain in the home directory of Kjell SM7GVF. The page has two additional interesting things, the words "Brighton 1981" and "Torremolinos 1990", both of which refer to IARU conferences. The reports for these meetings are online. In searching for any reference to the definition of the S-unit, the 1990 report shows that resolution "83-1" had the status of "Action completed", whatever that means. The 1981 conference document has all manner of interesting references, including "Log Forms and Summaries for International Contest Use", "Meteor Scatter qso procedure" and the definition of the standard way to determine Morse Code speeds using the word "PARIS" followed by a 7 bit word space, to name three. The one we're interested in is called "BM/134 - S-Meter Standards", appearing on page 33 and 34 of the 1981 report. It's a photocopy, so you can see the text from other pages superimposed. I'm making this observation because this is essentially a standards document, intended to be adhered to by industry and the amateur community. It gets better, or rather .. worse. The text that is referenced by Wikipedia uses numbers for the four elements, where BM/134 uses letters. The third item in BM/134 says that it applies for "bands above 30 MHz", but the document I just quoted appears to be unique in saying that it applies to "bands above 144 MHz". The fourth item, dealing with the way that the meter responds has been altered on BM/134. The text "+/- 2 ms and a decay time" are in a different font and at an angle. Worth noting that the change includes "ms" twice, rather than "msec" as the unit for milliseconds used elsewhere. Searching for a phrase within the standard, I discovered the Region 1 HF Manager Handbook v7.01, which appears to include the S-meter standard in chapter 11.1.2, but closer inspection reveals that the fourth item is missing, the one about quasi-peak detection. This is significant because the S-meter standard is based on a CW signal, not an SSB signal, which fluctuates. There's no reference as to where or when this was removed or by whom. These changes are repeated in subsequent versions of the HF Managers Handbook. There's other differences too, instead of using millivolt and microvolt as shown in the original BM/134 standard table, all units have been converted to millivolt for no discernible reason. The new table, including typo, is also copied everywhere. While we're at it, the original standard contains the letters "V", "E", "R", "O", "N" at the top. They don't show in the HF Managers Handbook either. This is curious, since last time I checked, those letters signify an organisation that at least some here will recognise, the "Vereniging voor Experimenteel Radio Onderzoek in Nederland", known to the the people who don't speak fluent Dutch, as the peak body for amateur radio in the Netherlands, VERON. Searching its website does not reveal their contribution to this standards document, which I have to say, is par for the course, much of our amateur radio history is poorly documented or archived, if at all, something which I've spent plenty of my time attempting to remedy over more than a decade, one article at a time. Moving on. The phrase I mentioned earlier bears reading out in its entirety. From BM/134: "We hope that the current recommendation will be followed by all equipment manufacturers, so that in a not too distant future one will know how to interpret the strength report of the other station." It goes on to say: "Societies should advise as much as possible their members about equipment manufacturers adhering to this recommendation and shall try to avoid publication of receiver designs which do not in principle use the recommended standards." Which brings me to you. What have you done lately about this? It's only been 45 years. Perhaps it's time to implement this? I can tell you that preliminary results show that the S1 level sensitivity associated with the radios that Randall showed me are reporting S1 when really they should be reporting about S4. You might wonder why this is the case? Calibration appears to be the underlying cause. While S9 itself is variable in accuracy, as-in some radios are more accurately close to -73 dBm, others are consistently 5 dB shy of that. When an S4 signal is reported as S1, then the 6 dB step size is not correctly implemented. Similarly, when an S9+20 is reported by a signal that's only 16 dB stronger than S9, there's more fudging going on. The differences between a signal with and without preamp are also worth noting as being inconsistent. In other words, the level and steps associated with S-meter units are all over the place, which is interesting, since the authors of the standard already alluded to this when 45 years ago they wrote: "Simple means for calibration of at least the 6dB level ratio should be published." While we're digging for causes. Why is there not a standards library associated with the IARU, where documents like BM/134 exist and with it their current level of application? Before you tell me, money, I'd point out that in 1981, IARU Region 1 had 263,945.88 dollars, or francs, guilders, pounds or glass beads in the bank, it's unclear which, since there's no units stated. At the 1990 conference IARU Region 2 had a reported net worth of $150,000 with $40,000 annual income and Region 3 reported that "its finances are also sound". How do I know? That's in those conference documents too. Curiously, the 1981 report states that "when presenting the 1981 and subsequent accounts the Treasurer would also prepare a brief report which would explain the reasons for items of such expenditure for which the purpose was not obvious." I wonder what happened to those explanations? So, what is the current status of BM/134 and what are the legal implications of me publishing it on my Github page? While we're at it. I realise that I can "fix" the Wikipedia page, but where do I point it at? I'm Onno VK6FLAB

You're invited into a legacy family audio business that refused to accept “good enough” on feedback control and instead chased the impossible: a truly zero‑latency, AI‑driven way to push your PA louder without squeals. You follow Devin Sheets from growing up on sound gigs to roaming European stages, then back home to build De‑Feedback plugin for working musicians, a live sound feedback plugin and on‑the‑fly impulse‑response generator that listens like a seasoned engineer: separating human voice, room reverb, background noise, and feedback in real time so you can grab at least 6 dB more gain before things start to howl. Along the way you see how NAMM sparked the idea, how inverse impulse responses and probability math beat old EQ and gate tricks, and how “homebrew AI” meant sneaking into every empty church at 3 a.m. just to teach the model what real rooms actually sound like. You also learn how to think like a modern working musician: using social media to find the right AI programmers across the world, leaning on LLMs to translate, collaborate, and even rate contractor work so you can move faster without losing control. You come away knowing you can drop a dedicated De‑Feedback box or plugin into almost any rig, from churches to touring consoles to tiny clubs, take it with you even when someone else is behind the board, and quietly stack the deck in your favor. In the end, it's a roadmap for how you run your own gigs and career: stay curious, embrace new tools, protect your sound, and Always Be Performing. 00:00:00 Gig Gab 524 – Monday, March 9th, 2026 March 9th: National Meatball Day Guest co-host: Devin Sheets from Alpha Labs 00:02:12 Let's Grow this Legacy Family Business Grew up doing sound Also a musician Lived in Europe Then came back and said, “let's grow this family business!” 00:03:44 We haven't “just solved” this feedback problem Went to NAMM for the first time, and was inspired There are automated EQ-based or gate-based systems PSE plugin from Waves 5045 for feedback 00:04:57 Why isn't there a “balanced audio”-type solution for Feedback Balanced Audio fixes hums and it just works. 00:08:24 NAMM is a great inspiration…and it inspired Devin and his team to seek a feedback plugin solution People get entrenched Inverse Impulse Response methodology 00:12:35 Training the AI to listen for three things: human voice, reverb, and feedback Created a de-reverb algorithm and went beyond that A probability calculation does the math 00:16:05 Truly zero latency for the plugin Workflow latency remains 00:19:32 I don't have any coding or AI background, but I have a gut feeling AI will fix this feedback problem Others: It's harder than you think Devin: I knew that it needed to happen 00:20:58 Finding an AI programmer who was interested in doing Experimented with some programmers, failed, learned some things! 00:21:09 Social Media to the rescue! Late 2023: Devin found a group of AI programmers who would be interested Sending large amounts of money to China…it's a risk! 00:26:30 At 3am, a text message: I think I've done it. Devin immediately started testing it himself “It seemed to work.” 00:27:17 Installing De-Feedback in Churches Sponsors 00:30:57 SPONSOR: Claude.ai – Ready to tackle bigger problems? Sign up for Claude today, which includes access to Claude Cowork, too, when you visit Claude.ai/giggab 00:32:43 SPONSOR: Squarespace. Check out https://www.squarespace.com/GIGGAB to save 10% off your first purchase of a website or domain using code GIGGAB. 00:34:20 What is an impulse response? Impulse Response: An audio picture of how the room sounds Popping balloons in a room/environment and recording the sound is a common approach for creating impulse responses 00:38:33 De-Feedback is an on-the-fly IR generator …and analyzer that's trained on the human voice, room reverb, background noise…and feedback 00:41:55 Finding the right programmers was the key …in addition to actually having the idea and the bullheaded persistence to make it happen. 00:44:46 Mind-melding was necessary And LLMs helped with translation! 00:48:39 Using AI to make it possible to collaborate with other humans 00:50:03 Using an LLM to rate the work of your contractors and employees 00:51:54 How do we get De-Feedback into the hands of working musicians US$499 for the De-Feedback plugin VST3 or AU plugin A higher-end Windows laptop can likely run it on its own Apple's Core Audio tech makes it difficult, but they're working on it. De-Feedback also sells a perfectly-tuned headless computer to do this Alpha Labs tried tons of interfaces that the Focusrite Scarlett keeps glitches out of the mix Waves SuperRack LiveBox 01:01:37 Where do we expand? Allen & Heath mixers? Midas/Behringer mixers? Paul Falcone, mixing Mariah Carey, wanted to use it! Robert Scovill talking Rock Hall on Gig Gab 01:05:18 Homebrew AI! Training EVERY room he could find “Can you let me into your empty church at 3am?” – To record IR to then train the data set for De-Feeback 01:07:25 Creating your own AI model 01:08:13 What's the future look like? Acquisition? Demands for security? – Planning for it all 01:09:26 You can get this and bring it with you to gigs where someone else is doing sound De-Feedback Option 1 Allen & Heath Qu-5's Feedback Eliminator De-Feedback gets at least as 6dB more gain before feedback 01:17:46 Gig Gab 524 Outtro Follow Devin Sheets And Alpha Labs Facebook and Instagram YouTube for Alpha Labs Contact Gig Gab! @GigGabPodcast on Instagram feedback@giggabpodcast.com Sign Up for the Gig Gab Mailing List The post De-Feedback Plugin for Working Musicians: More Gain, Less Feedback – Gig Gab 524 with Devin Sheets appeared first on Gig Gab.

What exactly is a decibel, and why is it measured on a logarithmic scale? In this episode of The SOUND Project, Gavin breaks down the science of sound intensity, exploring how decibels work, why our ears perceive loudness the way they do, and how this knowledge applies in both studio and live sound environments.We'll cover:-The origins of the decibel and Alexander Graham Bell's connection-Why decibels are measured logarithmically-Real-world examples of decibel levels (from quiet homes to rock concerts and jet engines)-The importance of hearing protection and how filters work-How decibel changes are perceived versus measured-How multiple sound sources combine in terms of dB levelsWhether you're a mixing engineer, a live sound tech, or just curious about how loudness works, this episode gives you a solid foundation in understanding decibels.

Whether you're just starting out or refining your setup, great audio is the foundation of a great podcast. In today's episode of Podcast Insider, we share practical tips for getting professional-sounding results—covering mic choice, positioning, background noise reduction, recording formats, and techniques to boost your on-mic confidence. Follow these steps and you'll sound clearer, warmer, and more engaging to your listeners. Today's Hosts: Mike Dell and Todd Cochrane

Send us a textWe break down essential technical concepts for low-voltage professionals, from proper termination block spacing to ladder safety protocols. • Use the four square inch rule for every four-pair circuit when planning termination block wall space• UPS batteries perform best at 77°F with life reduced by half for every 10°C above optimal temperature• Speaker coverage for speech intelligibility requires checking polar plots at 2kHz with attention to the -6dB drop point• Stranded patch cords have 25% more attenuation and require careful handling to prevent impedance swings• Work breakdown structures should include planning, kickoff, actual work, and closeout phases• Outside plant installations involve public, private, and railroad right-of-ways requiring proper permits• Ladder safety requires checking spreaders, rubber boots, weight ratings, and never using damaged equipment• Never stand on the top two rungs of a ladder or allow multiple people on standard laddersFor more detailed information on ladder safety, check out our 34-minute show covering top ladder safety tips and common mistakes to avoid.Support the showKnowledge is power! Make sure to stop by the webpage to buy me a cup of coffee or support the show at https://linktr.ee/letstalkcabling . Also if you would like to be a guest on the show or have a topic for discussion send me an email at chuck@letstalkcabling.com Chuck Bowser RCDD TECH#CBRCDD #RCDD

On episode 292 of the BSP, I discuss adblockers and how they impact creators, the Lewitt LCT1040, youtube shorts content, the struggle of choosing microphones to review, pan law compensation and why obs clips at -6dB, The Towering Inferno and the new 25th Anniversary Arrow Video release of Mallrats by Kevin Smith.   Subscribe to the full audio podcast at http://www.bandrewsays.com   Gear Used This Episode (Affiliate Links): Lewitt LCT1040: na. Yellowtek M!ka: https://www.yellowtec.com/mika.html Universal Audio x8: https://imp.i114863.net/zMg2r Sennheiser HD650: https://geni.us/sennhd650   As an affiliate I earn from qualifying purchases.    Ask Questions: https://www.askbandrew.com Merch; https://teespring.com/stores/podcastage-store Discord: http://www.podcastage.com/discord   00:00 - Intro 01:15 - AdBlockers Impact on Creator Income 03:15 - Lewitt LCT1040 08:40 - WYHTS: Using Lav Mics with XLR 10:10 - WYHTS: Suggestions for Mic Shorts Content 11:53 - WYHTS: Your sE Dynacaster is Broken? 13:45 - WYHTS: Review the Revelator iO24!!!! REEE! 16:00 - Ask Bandrew 16:45 - Email 1 17:45 - Have You Tested the Microtech Gefell M930 20:30 - Voice Submission 2 21:40 - Does OBS Still Clip at -6dB Mono? Pan Law Compensation Demonstration 25:30 - Analog Limtiers? 27:40 - Feedback on Vocal Processing 29:00 - Email 3 29:50 - Broadcast Dynamic Mic Recommendation 32:45 - Voice Submission 4 34:30 - Removing RF Interference? 39:30 - Movie(s) of the Week 44:50 - Outro

On episode 215 of the BSP I briefly discuss the new Twitch Safety Advisory Council, and the Logic Pro 10.5 update. I then answer a lot of questions covering why OBS audio is clipping at -6dB, What Microphones I use, SKYPE Audio & OBS, the State of Freedom of Speech, and a whole lot more.   Subscribe to the full audio podcast at http://www.bandrewsays.com   Gear Used This Episode (Affiliate Links): Manley Reference Cardioid: https://imp.i114863.net/GWaN9 Hakan P110 Pop Filter: https://imp.i114863.net/Za2Ag Universal Audio x8: https://imp.i114863.net/zMg2r OC White ProBoom Ultima https://www.ocwhite.com/broadcast-arms/proboom-ultima/proboom-ultima-lp-mic-booms.html Sony MDR7506: https://geni.us/7506   Twitter: @bandrewsays Ask Questions: https://www.askbandrew.com Merch; https://teespring.com/stores/podcastage-store Discord: http://www.podcastage.com/discord   00:00 - Intro  00:55 - Twitch Forms Safety Advisory Council Twitch Announcement: https://blog.twitch.tv/en/2020/05/14/introducing-the-twitch-safety-advisory-council/ 03:11 - Logic Pro 10.5 Update Logic Pro Announcement: https://www.apple.com/newsroom/2020/05/apple-unveils-biggest-update-to-logic-since-the-launch-of-logic-pro-x/ 04:54 - Manley Reference Cardioid 07:20 - WYHTS: What Are the Property of Podcast Stickers? 09:23 - WYHTS: Should I Leave SKYPE Audio at 100%? 11:50 - WYHTS: Isn’t a Podcast Using Microphones You Review Relevant to Your Main Channel? 15:50 - WYHTS: Should I Use Your OBS Settings With the GOXLR?  17:00 - WYHTS: Why is OBS Clipping at -6dB!? 22:19 - Ask Bandrew 22:55 - Voice Submission 1 24:20 - Additional Thoughts on Rode M2 28:46 - Voice Submission 2 28:52 - What Microphones Do I Use? 31:14 - Voice Submission 3 32:31 - Thoughts on the State of Freedom Of Speech 38:15 - Announcements Fethead Placement: https://podcastage.com/rev/fetheadmicint Fethead Noise Improvement: https://podcastage.com/rev/micactivatornoise Https://www.bandrewscott.com http://livestreamforthecure.com/ 39:36 - Outro

Aaron shows you how to convert a mono audio file to stereo in FCPX. With a simple mono-to-stereo conversion, there is a -6dB loss that happens. Aaron shows you the trick of how to change the settings so you can overcome the -6dB drop from the conversion. The post How to convert mono to stereo audio without the -6dB loss in FPCX appeared first on AARON LINSDAU Adversity Expert.

A voltage-controlled filter (VCF) is an electronic filter whose operating characteristics (primarily cutoff frequency) can be set by an input control voltage.[1] #Voltagecontrolledfilter are widely used in analogue music #synthesizers. Depiction of cutoff frequency of a low-pass filter, showing Butterworth response A music synthesizer VCF allows its cutoff frequency, and sometimes its Q factor (resonance at the cutoff frequency), to be continuously varied. The filter outputs often include a lowpass response, and sometimes highpass, bandpass or notch responses. Some musical VCFs offer a variable slope which determines the rate of attenuation outside the bandpass, often at 6dB/octave, 12dB/octave, 18dB/octave or 24dB/octave (one-, two-, three- and four-pole filters, respectively). In modular analog synthesizers, VCFs receive signal input from signal sources, including oscillators and noise, or the output of other processors. By varying the cutoff frequency, the filter passes or attenuates partials of the input signal. In some popular electronic music styles, "#filter sweeps" have become a common effect. These sweeps are created by varying the cutoff frequency of the VCF (sometimes very slowly). Controlling the cutoff by means of a transient voltage control, such as an envelope generator, especially with relatively fast attack settings, may simulate the attack transients of natural or acoustic instruments. Historically, musical VCFs have included variable feedback which creates a response peak (Q) at the cutoff frequency. This peak can be quite prominent, and when the filter's frequency is swept by a control, partials present in the input signal resonate. Some filters are designed to provide enough feedback to go into self-oscillation, and it can serve as a sine-wave source. ARP Instruments made a multifunction voltage-controlled filter module capable of stable operation at a Q over 100[2]; it could be shock-excited to ring like a vibraphone bar. Q was voltage-controllable, in part by a panel-mounted control. Its internal circuit was a classic analog computer state variable "loop", which provided outputs in quadrature. A VCF is an example of an active non-linear filter. The characteristic musical sound of a particular VCF depends on both its linear (small-signal) frequency response and its non-linear response to larger amplitude inputs. --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app --- Send in a voice message: https://anchor.fm/vegansteven/message

The Royal Opera House orchestra was rehearsing Die Walküre. For more than three hours violist Chris Goldscheider sat in front of twenty brass players belting out Wagner at 90dB. His hearing was permanently damaged. The Opera House argued that artistic standards took precedence over the risk of acoustic shock, but the courts thought otherwise and awarded Goldscheider substantial damages. A musician’s job is to create sound. Rock musicians ramp up the amplifiers and often lose their hearing temporarily after a particularly loud concert. Many don’t acknowledge the warning. Over time, even violinists can lose 6dB of hearing in their left ear. Many publicans and restaurateurs foster sound. They rip out partitions, strip out soft furnishings and turn up the music. Chatter turns to shouting and then to screaming, and by the time the sound level is 90dB – that’s the same as a pneumatic drill – they have created the vibe they think their clientele enjoy. At least that’s what many of them told Action on Hearing Loss. I wonder. You can’t pour your heart out, or even chat to your mates, against a wall of sound. When a bartender brings a legal case for acoustic damage, publicans may think again. "Noise affects patient care. If staff are distracted or unable to clearly hear information or instructions, lives are at risk." Silence is elusive. Over four days, walking along the Thames path from its source to Oxford, we were out of the sound of traffic for just half an hour. Military jets scream over the remote Highlands and police helicopters clatter over secluded corners of Regents Park. Libraries now entertain kids singing nursery rhymes, art galleries display video installations, and the espresso machine thumps and grinds in cafes where people go to read and work. Who cares Hospital calm? Gone are the days! Machines, phones, bleeps, call bells (left unanswered because they’re short-staffed), crashing trolleys, long visiting hours with noisy families . . . the noise level in ITU can be over 100dB. Noise affects patients. A Swedish study found that loud environments triggered more re-admissions. More hypnotics are prescribed. Patients self-discharge to get a good night’s sleep. Noise affects patient care. If staff are distracted or unable to clearly hear information or instructions, lives are at risk. Noise affects us all. Raised blood pressure, increased risk of cardiovascular problems, poor sleep and its attendant consequences, low birth-weight, obesity, diabetes and cognitive impairment . . . these are some of the consequences. My worst experience of noise was in Santiago de Cuba. The ancient, grinding engines of trucks and buses which had long lost their exhaust silencers woke us at dawn and deafened us until nightfall. We found relief at a cliff-top café. There was a pervasive smell of drains but, like most people, we could put up with pollution better than noise. Nearly 2000 years ago Juvenal listed noise as one of the seven plagues of Rome (along with high rents and fashionistas). Victorians were assailed by the hawkers’ cries, wooden clogs on the cobbles, clattering carts – rubber tyres were a late 19th century innovation. Now, noise has been weaponised. In Guantanamo it’s been used as an instrument of torture. Holed up in the Vatican nunciature, Panamanian leader General Noriega didn’t surrender until the CIA blared rock music into the building. (You can hear it on YouTube). In contrast, shopping malls broadcast Beethoven to see off hooligan loiterers. Our valuation of noise is very subjective and poorly related to the damage it does, which is determined by its acoustic intensity and how long we are exposed to it. The decibel scale is logarithmic, so a 70dB sound is ten times more intense than 60dB. The safe exposure time for a 90dB lawnmower is two hours; for 1...

What use is an F-call? Recently I spoke about digital voice communications. I made mention of the CODEC2 project being developed by Dave Rowe, VK5DGR. I also made reference of the kinds of things that digital voice improves, battery life, channel separation and bandwidth. One of the things I didn't mention, mainly because I still had to learn what it meant, is that CODEC2 has an estimated 13dB gain over Analogue FM. To explain what that actually means, you might recall that an S-point is 6dB, that means that if you use CODEC2, you gain more than two S-points, that's a little like turning up the transmitter power from 10 Watts to 200 Watts. If you look at it another way, if you have a Yagi and you install the same Yagi next to it, and connect it up properly, you've doubled the power and gained 3dB. If you do that again, you have 4 antennas and 6dB, if you do it again, you have 8 antennas and 9dB, again, 16 antennas or 12dB gain. So, the performance that we're talking about is something that you can either visualise as turning up the power from 10 Watts to 200 Watts, or using an antenna array with 16 antennas. So what is this magic thing called CODEC2? Well, as I said previously, a CODEC is a piece of software that encodes and decodes stuff. An example that you might be more familiar with is an MP3 file. You open your sound file, and save it as an MP3. The new file is much smaller but it retains most of the fidelity of the original when you play it back. The same is true for other things in use. Your mobile phone uses a GSM CODEC to make your voice travel across the airwaves as bits, rather than raw audio, like the old analogue phones we used to have. The aim of all of this is to reduce data use, to increase availability of channels and to deal with error correction. CODEC2 does all that, for us, here, in Amateur Radio Land, and of course, it can also be used in the rest of the world, for example for mobile phone communications, making it possible to use less power to transmit the same signal and thus use less battery, making your phone last longer. I'm looking forward to a CODEC2 mode on my radio to go with the AM, FM and SSB modes already there. I'm Onno VK6FLAB

What use is an F-call? When you get an amateur radio license, you learn that different license classes have different power limits. The basic power limit in Australia, the foundation license, or f-call, has 10 Watts as the limit. The standard license has 100 Watts and the advanced license has a maximum legal limit of 400 Watts. It's natural to think that more power gives you more reach, but realistically, what does that look like, what is the difference between 10 Watts and 100 Watts? Can you really notice a difference? From my own experiments, I can confirm that it's possible to talk to the opposite side of the earth with 5 Watts, but was that a fluke, or is there more to it? What is the difference? All things being equal, that is, the same radio, the same conditions, the same antenna, the same location, etc. - the difference between 10 Watts and 100 Watts is a 10-fold increase, or, if you have 400 Watts at your finger-tips, that's 40 times more - right? Not quite. If you recall, a dBm is a decibel-milliwatt, or said differently, 0dBm is the equivalent of 1 milliwatt. If you double the power, 3dBm, you're looking at roughly 2 milliwatt. 10 Watts is the same as 40dBm. 100 Watts is the same as 50dBm. That means that between 10 Watts and 100 Watts, there is 10dB difference, that is, there is a 10dB gain if you go from 10 Watts to 100 Watts. On a HF radio, on your S-meter, an S-point is defined as 6dB. That means that the difference between a 10 Watt contact and a 100 Watt contact is less than 2 S-points. The difference between 100 Watts and 400 Watts is even smaller. 400 Watts is 56dBm. As I said, an S-point is 6dB, so, the difference between a contact made using 100 Watts and one made with 400 Watts is one S-point. An F-call using 10 Watts, is 3 S-points worse off than an Advanced call using 400 Watts, all else being equal. Of course, depending on the conditions and the deafness of the operator on the other end, that might well be the difference between making the contact or not. If you start at S-9 with 400 Watts and there's 30dB path loss because of band conditions, you end up at S-4, but if you start with 10 Watts at S-6, you end up at S-1. The path loss has a bigger impact on your readability than the amount of power you're putting out. The main take-home is that an F-call can make contacts with their 10 Watts and they're only 3 S-points behind the big guns with their fancy Advanced license. Before you start mouthing off about the 1500 Watts allowed in the United States, that's just under 62 dBm, so just one more S-point. That's not to say that there is no benefit in upgrading your license; access to bands and modes, home built transceivers and other perks, but power shouldn't be why you upgrade. One final observation. I've noticed that if you're confident on-air, other stations hear you better. That might mean that the 400 Watts that you have as an advanced licensee might make you more confident, thus making more contacts. Be brave, be confident, make your contacts with as little power as you can. I'm Onno VK6FLAB

What use is an F-call? You've come across the term dB, or Decibel. Likely you've heard of dBi as well. These terms are all related to Decibels, but mean completely different things. A decibel, named after Alexander Graham Bell, is a RELATIVE measure of two different power levels, that is, one power level compared to another power level. 3dB is about twice as much power, 6db is about four times as much, and 10dB is exactly 10 times as much power. This means that you can say that a feedline has 6dB loss, that is, you need to put 20 Watt in at one end to get 5 Watt out at the other. In short, a dB is a ratio between two levels of power, in the feedline case, the power in vs. the power out the other end. In antenna land, you'll have heard dBi as the measure of the amazingness of an antenna. A dBi is a measure of gain of an antenna when compared to an ISOTROPIC source. This is a theoretical reference, that cannot actually exist in nature, but at least it's always the same, which allows you to compare two antennas to each other when their gain is both expressed in dBi. You might also come across a dBd, or antenna gain when compared with a dipole. A dipole in itself can be compared to an Isotrope. Its gain is 2.41 dBi or 0dBd. Which incidentally goes to why many antenna manufactureres play silly games with dBi and dBd. An antenna described as 24 dB should send you back to the manufacturer to ask them, 24 compared to what? If it's 24 dBi, it's compared to an isotrope, if it's 24 dBd, it's compared to a dipole. This means that there could be a 4.81 dB difference between two incorrectly named "24 dB" antennas. There's more than this, think about dBW, dBV, dBu, dBmV, dBA, dBZ and many, many more. The thing to take away is that a dB is a relative term. One compared to another. If only one's specified, you don't nessicarily know compared to what? dBi references it to an Isotrope and dBd references it to a dipole. I'm Onno VK6FLAB