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Mother Nature is amazing. Vegetation will find a way to grow almost anywhere, including places at your transmitter site that can be problematic.

Fig. 1: One reason to inspect remote site equipment thoroughly.

You can bet the satellite signal from the dish in Fig. 1 gets even worse when the leaves come out. The problem gets worse the closer you get to the dish. We can see in Fig. 2 that the sections of the dish have actually been deformed by the vines.

Yet another reason why site inspections need to occur regularly.

***

We’ve gotten encouraging comments from engineers reading Frank Hertel’s and Bill Ruck’s suggestions on rodent control.

Fig. 2: A close-up shows that the vines are growing right up through the dish.

Bill pointed out that raptors provide “free” control, and offers this blog from the Cornell Lab of Ornithology to back up the claim: https://tinyurl.com/raptorfood. Here’s an excerpt (edited for style):

“Nonbreeding adults eat about a quarter-pound of food daily, or a tenth of their body mass — that’s about five small mammals. Nestlings start feeding themselves (swallowing lemmings whole) at about 16 days old. It’s estimated that a brood of two nestlings requires 26 pounds of food during the 40 days between hatching to fledging.”

[Read: It’s Time To Inspect That Air Conditioner]

Various vole and mouse species average about 1 ounce in weight (lemmings in the Arctic weigh a little more), so, if you do the math, every adult Roughie eats four to five small mammals every day (about 1,460 annually), and two nestlings consume roughly 278 rodents in only their first 40 days. Clutch size is usually three to five eggs, so the actual number of rodents consumed by nestlings is often much larger.

Red-tailed hawks are more common and are around all year long. They have about the same eating habits. Can anybody trap 1,500 mice a year using another method?

***

Among the many “take-aways” from the NAB Show each year are various useful promotional items that vendors offer attendees.

Fig. 3: Inovonics will send you a free Radio Hero Swag Bag (modeled here by Travis Tibbot of BGS). Just email sales@inovonicsbroadcast.com.

Since this year’s show was canceled, Inovonics Broadcast President and CEO Ben Barber is offering an Inovonics Radio Hero Swag Bag, pictured in Fig. 3, to broadcast engineers who request one by email to sales@inovonicsbroadcast.com. Just reference the swag bag mentioned in Workbench.

I won’t spoil the surprise, but you will find the contents useful.

***

With so many station voices operating from remote locations, Rob Atkinson, K5UJ, reports on an inexpensive equipment rack from, of all places, IKEA.

It’s called a Lack Rack. It’s a short table, the legs of which are placed at the perfect distance for mounting rack equipment. The flat table top provides a shelf top. It’s nothing fancy, but for 10 bucks, it might solve the question of how to mount several pieces of rack equipment for a temporary lash-up.

Find specifics at https://tinyurl.com/ikealackrack, and the IKEA product is here: https://tinyurl.com/ikearack.

***

James Potter owns Cutting Edge Engineering, which provides radio station technical service. James tried the free Paint.net software that we described in the March 4 issue. He writes, “Super-duper! Much more functionality than MS Paint, and — best of all — it’s free! Thanks!”

Thanks, James, for letting readers know. Dan Slentz, who told us about the free image and photo editing software for PCs, likes the innovative and intuitive user interface, which includes special effects. Glad the column could help.

***

In a previous Workbench column, I referred to transmission line “hot spots” detected by infrared camera inspection. Many of these hot spots occur at rigid line junctions, or 90-degree elbows where a bullet is overheating and ready to fail.

Fig. 4: Myat’s 3 1/8 bullet. The blue ring shown on one end of the bullet is Myat’s anti-split device.

I received a message from an engineer wanting to know more about this — specifically, what is a “bullet”?

For those who need an explanation, simply put, a bullet joins the two center conductors of transmission line together (see Fig. 4 to get a better idea). Because of its cylindrical shape, it looks like a big piece of ammunition, hence its name.

Each end of a bullet fits inside the corresponding center or “inner” piece of transmission line. Improper bullet installation, wide temperature swings or movement of the line over time can cause the bullet to weaken and not make a good tight connection. The result is heat buildup and eventual failure.

Keep in mind, there’s usually a lot of power passing through this center conductor. The whole point of periodically measuring the temperature of these junctions is to spot a potential failure before catastrophic damage occurs.

John Bisset has spent over 50 years in the broadcasting industry and is still learning. He handles western U.S. radio sales for the Telos Alliance. He holds CPBE certification with the Society of Broadcast Engineers and is a past recipient of the SBE’s Educator of the Year Award.

 

The post Mother Nature Can Both Hinder and Help Your Station appeared first on Radio World.

The House has passed the HEROES (Health and Economic Recovery Omnibus Emergency Solutions) Act, which would count individual TV and radio stations as small business in terms of forgivable loans ever if they are part of larger broadcast groups that, as a whole, would not qualify.

Broadcasters and newspapers have been pushing for that access to funds, but the victory is likely only symbolic since Republicans in the Senate have said it was DOA there, and the President has signaled he would likely veto it if the $3 trillion COVID-19 aid bill, of which the small business loans for media outlets is a tiny part, made it so his desk.

[Read: NAB Says C-Band Cost Structure Should Await Satellite Transition Details]

“NAB applauds House passage of the HEROES Act that includes expanded access to Payroll Protection Program loans for local media outlets,” said National Association of Broadcasters president Gordon Smith “As local radio and TV stations and hometown newspapers struggle with historic advertising losses, it is critically important they have access to resources to support lifesaving journalism that keep families and communities out of harm’s way.”

While the HEROES Act is unlikely to become law, separate, standalone bills that would create the expanded PPP access and that have bipartisan support, have been introduced in both the House and Senate.

 

The post NAB Applauds HEROES Act appeared first on Radio World.

You may have noticed that a lot of new audio coming from record companies and music services sounds heavily compressed, distorted or clipped. When you look at these audio files as a waveform, you can see the clipping, especially when comparing it to music from just 10 years ago, whether from the record company or a service like TM Century.

This article is about the quality of audio radio stations are receiving from music providers today.

To put this together, I spoke with numerous people in our industry, including three experts at well-known audio processing companies mentioned below, to get their take on what’s happening and how we can provide great audio to listeners.

What I found is that there is no single answer. But these experts agreed that it’s a problem and that quality is an issue.

Everyone has their own take on how to process audio that is (to put it plainly) either recorded too hot and clipped or processed out the wazoo to begin with.

Part of the problem with dealing with audio is not simply the fact that it’s frequently hot and clipped, but we are intermixing great audio with full dynamics (from older content) to our own studio material along with newer, highly processed content.

Where do you start and how do you set your processing when your source material is so inconsistent? If you process for new content, your old stuff could sound lifeless. If you process for old content, your new material may have no dynamic range (or feel processed out that wazoo).

Challenges

If we start at the beginning, we know that getting music for radio stations can be a challenge, unless you’re a major-market station with record companies still interested in getting that airplay.

Smaller stations may have to be creative in finding music including subscription services. This isn’t to say that music isn’t available all over the web, and there are some “non-paying” ways to acquire music (not recommended) from posted videos and download sites.

These are not necessarily legal ways to find music; they also may be compressed or have had multiple types of compression reducing the quality to that of a “personal MP3 player” … or even worse.

In the past, there were some great music providers that are no longer in the game (like the old TM Century), and record companies provided music with great dynamics and counted on the radio station to really do their processing on the playback end. Today, there are DJ music service and paid content download sites, but I believe most of us find these files highly processed or even clipped (see examples).

As a bit of an audiophile, I pay attention to quality. I truly want to see dynamic range and peaks that more resemble analog audio than a file with a minimal amount of dynamics and an apparent “flat lining” or clipping of the peaks.

For one thing, I always recommend staying true to “CD quality” with WAV-only files that come from CDs or uncompressed as original WAVs and never converting an MP3 to a WAV. As in life, you will not get something for nothing by turning an MP3 into a WAV. It’s still MP3-quality with just a different suffix to it.

In radio, we process (some more than others) for a multitude of reasons. First, since radio is often listened to while driving we want to overcome the background sounds or “road noise” by bringing up quiet passages without completely destroying the song’s dynamics. We also want our music to have “more punch” than other stations or other sources available to the listener.

Basically, many of us want bigger, brighter, louder and more punch. Considering FM’s own high-frequency limitation of 15 kHz, we have a slight disadvantage to the quality of a stream, but the advantage of something a little more “pure” or “real” in the fact that it’s not being “squashed” for streaming (plus the lesser chance of any “digital weirdness”).

We really could go back and forth on advantages (radio goes anywhere) and disadvantages (e.g., multipath) of radio, but paying attention to the quality of our files is a great starting point. It’s simply because we can never get any better than the quality of the original file.

Comparisons

Recently I’ve begun comparing audio files from TM Century’s old Gold Disc files versus a current music service. I’m shocked at what I found.

Let’s compare a few WAVs to show what I’m talking about. To do this, I’ve used Adobe’s Audition to open both files. No changes were made to any setting, and the screenshot is taken from unaltered editing images. All of these files are native WAV files, no conversion, no normalizing, nothing changed for what you’ll see.

First, a new song by Weezer called “Can’t Knock the Hustle,” followed by U2 and “Where the Streets Have No Name.” See Fig. 1.

 

Fig. 1: Weezer “Can’t Knock the Hustle” vs. U2 “Where the Streets Have No Name.”

You can see the difference, but what are we seeing? There appears to be so much processing on Weezer that there is very little left of the dynamics of the music. In other words, everything is loud! And what happens when we process it? The smallest amount of dynamics that were left are completely eliminated.

What does this translate to? Most program directors and consultants would likely say it will be loud on the radio but it will possibly be distorted or clipped, and that feeding this to a listener will likely result in “listener fatigue.” Simply put, our ears need those dynamics because they aid in providing an ear break.

More Songs

This is Panic at the Disco and Def Leppard (a generally “loud” group). Again, a very noticeable difference in processing and dynamics. See Fig. 2.

 

Fig. 2: Panic at the Disco “High Hopes” vs. Def Leppard “Pour Some Sugar On Me.”

Switching gears, another newer song (from 2016) was DNCE’s “Cake By the Ocean” and The Romantics’ “Talking in Your Sleep.” Again, heavily processed but with a little more dynamics versus what appears to me a more heavily processed older song. See Fig. 3.

 

Fig. 3: DNCE “Cake By the Ocean” vs. The Romantics “Talking in Your Sleep.”

What is our takeaway from all this? Though this is just three examples, I’m finding new music generally follows these two examples. What I’m seeing is very little in terms of dynamics, some aggressive processing (which includes clipping) and a much different sound.

I spoke with a producer at the company that distributed the first two newer examples and specifically asked if they are doing processing; his response was that they are doing nothing to the audio files and these are coming from the music companies this way.

This leaves us in a bit of a quandary. For a new music-based station (playing lots of current pieces but with older material as well), we might find that to “keep the playing field level,” we may need to preprocess the old song files prior to air (something I generally never do other than trim the front and back when needed), increase our mic processing and reduce our own overall main processing.

This also should make us aware of the potential impact on our listeners and their own “ear fatigue” with the content we air. If we are seeing shorter listening time and playing newer music, we might ask if the younger audience has a shorter attention span, or if we’re simply killing their ears with overprocessed material.

I spoke with three well-known radio audio processing gurus — Bob Orban of Orban Audio, Frank Foti of Omnia/Telos and Jeff Keith at Wheatstone. I heard a consistent theme: Audio is coming in much louder than it ever did. Ironically, this negatively affects the louder portions of the audio. The dynamic range is eliminated.

An additional lesson is that it’s a good idea to bring the overall audio levels of the new content down (the amount varies according to who you ask).

That is something we all know they would do, and that we can appreciate. I’d certainly like to tell you which one is right and which solution is best, but that would be like me telling you which color is best. A lot of this is subjective, and much of it can also be proven by test gear. But the results of the test gear also can be open to interpretation. So when it comes to the available products by our audio processing companies (any of them), a lot will be left up to the individual and also how that processor sounds in their own air chain.

Exploring

Consider exploring your audio files and weighing your processing vs. the content and the variation between the audio files. Be sure that all audio files you air are consistent in level. This, at least, is an excellent starting point. Depending on whom you ask, –2 dB down or even more may be the point where you want all your audio files to reside. Ultimately, the determination of whether you preprocess audio files prior to your on-air (or streaming) audio processor is a call you will need to make.

Fig. 4: The DeClipper control panel shows 1% tolerance.

By using audio editing software, it’s possible to dig into the waves to really see what’s happening. Using Adobe Audition, I first look at the properties of the file and scan it under “Diagnostics.” There are presets under “DeClipper,” but I found one that allows for some peak restoration. I start with reducing the file by –2 dB prior to running the Diagnostic DeClipper. After it indicates errors (newer audio files can have hundreds, while material like that from the old TMC Gold Discs usually have none), I run Repair.

At that point, I go with a percentage and “normalize” the audio to –1 dB down. This reduces everything equally so only the peaks hit –1 dB. By doing this, I know my processor (both on-air and streaming) will be seeing consistent levels. See Fig. 4.

Fig. 5: The Weeknd’s “Blinding Lights” as originally delivered, note lack of peaks leading to poor dynamic range.

A file may start out looking like this example. The following is a song “as delivered” by the music provider. You can see how extreme the level is. The song is “Blinding Lights” by The Weeknd. See Fig. 5.

Fig. 6: The Weeknd’s “Blinding Lights” reduced by –2 dB, note open headroom and available bottom.

The same song reduced by –2 dB (Fig. 6).

Fig. 7: Lower left pane shows errors detected in The Weeknd’s “Blinding Lights.”

Then the song is analyzed to find what Audition recognizes as clipped areas. Audition noted 333 errors (Fig. 7).

Fig. 8: The DeClipper add adds back in some of clipped peaks.

And finally, a –1 dB reduction overall and “the fix” is applied. This is how the resulting file looks  (Fig. 8).

It’s better than what it was, and audibly has a cleaner, “less crunched” feel to it.

Unfortunately, these highly processed audio files (intended for broadcast) seem to be the norm. This forces us to really consider all of our audio content and how to process it. It also requires us to think about our own recordings including commercial and PSA production audio files.

How does recently produced material stack up compared to old music audio files? What about in comparison to currently produced music? How we preprocess the audio we pass off to our audio processors needs to have consistency.

The manufacturers of our processing gear recognize what we are dealing with and they’re using their own magic to help us maintain great audio for our listeners as well. Just keep in mind that they all have slightly to greatly different ways of doing this, so your ears (and those of possibly the music director, program director, operations manager, general manager, et al) may want to weigh in on this.

And don’t forget that webstream audio will very likely differ from the air audio, so be aware that all your audio should be considered when it comes to processing and preprocessing.

Dan Slentz has been chief engineer at radio stations from Athens to Zanesville (Ohio), and Dallas to Denver. He is also an Air Force vet who worked with  Armed Forces Radio & TV from 1986–90 in Spain.

 

The post A Quality Audio Crisis in the Music Industry appeared first on Radio World.

IBC has announced the cancellation of this year’s edition due to the COVID-19 health crisis.

In a statement, IBC CEO Michael Crimp said that in the context of the pandemic “as governments announce the route forward, it has become clear that a return to (a new) normal is unlikely to be achieved by September,” he declared.

“Right now, despite the best work of the IBC team and our Dutch colleagues, there are still many unknowns. Therefore, we cannot guarantee we will be able to deliver a safe and valuable event to the quality expected of IBC.”

Crimp revealed plans to launch virtual IBC week. He added that the organization would continue to engage with the industry through its digital platform IBC365.

IBC2020 was scheduled to take place Sept. 11–14 at the RAI convention center in Amsterdam. Companies including Panasonic, Ross Video and Stirlitz Media had already announced that they wouldn’t be exhibiting at this year’s show.

The post Organizers Cancel IBC2020 appeared first on Radio World.

The author is membership program director of the National Federation of Community Broadcasters. NFCB commentaries are featured regularly at www.radioworld.com.

A social media giant’s decision about its workplace prompts questions of culture. It also has resonance with dialogs at community radio and college radio stations at this moment.

The Northern California-based Twitter announced that it would permit employees to work from home forever. It is one of the most stunning reactions among corporations, many of which have had to make major adjustments in the aftermath of the coronavirus outbreak. Many companies are choosing to have staggered returns or other models to protect employees. Twitter’s decision is a rarity, though it remains to be seen what “forever” really means.

Across the nation, community radio stations are having similar deliberations: when will a station return to normal operations, and what will normal be?

[Read: Community Broadcaster: Underwriting’s Murder Hornet]

As I wrote about in a previous column, there are a range of considerations for stations. They include understanding volunteers’ relationships with vulnerable communities and their own risk for illness; determining protocols for access to the public and in-studio guests; what live performances in a station look like during a pandemic; and how to keep a studio clean and safe. And, to be sure, plenty of organizations had to scramble mightily to come up with the means to continue to deliver programming and serve their audiences.

At several stations, there is intense internal pressure to have live DJs back in the studio immediately. At others, the approach is still very measured. Wherever your station falls in this spectrum, a step back to look at why we’re here — community service — is crucial.

Now that so many stations are slowly finding their programming groove, and the ability of volunteers and staff to deliver radio-quality content from home for pennies is easier than ever, maybe it is time to ask if this new normal is potentially beneficial to community radio stations and to volunteers.

There are, of course, tremendous benefits to having many people interacting in one place. Learning has long been proven to be much more impactful when it is done with others. Exchanges of ideas take place. And, for many volunteers, community radio is exemplified by live programming.

However, what Twitter and others have acknowledged is also true. You can be very effective and deliver excellent content outside of the building. So long as the quality and the effort are there, it can be a nice perk for volunteers to produce remotely. For staff members, especially those whose work may not require constant presence on the premises, remote work has its plusses too.

Staffing questions after an economic calamity abound for many community radio stations. Large public media organizations are looking to reduce pay and change up the workplace, as projected economic declines loom. Community media organizations seldom have the same financial reserves as the larger stations, and one might expect such reductions may happen among community radio stations, while possibly keeping work-from-home days to save staff commute time and giving them extra hours to spend with family.

No one wants to lose staff or the culture a station holds dear. There are no good guys or bad guys when everyone is concerned about stations’ future. Nevertheless, it is incumbent on every station to think about how they serve the listener most effectively. If the way things have always been done serves best, great. If this period has opened up new questions, now is the time to consider them as well.

 

The post Community Broadcaster: Remote Forever appeared first on Radio World.

Later this year we celebrate the 100th anniversary of radio broadcasting as we know it, which came into being with the transmission of U.S. presidential election returns in the fall of 1920 by station KDKA.

There are a number of documented attempts at broadcasting to the general public prior to this date; none of these other pioneering operations really caught on and captivated much attention, save for the amateur radio audience, which likely viewed them as just an experimental curiosity having some entertainment value.

Obviously, the KDKA project didn’t just happen. Its progenitor Frank Conrad didn’t stop by the stockroom of his employer Westinghouse Electric and requisition a pile of parts that, on a whim, he turned into a radiotelephone transmitter.

[Read: When Brute Force Transmitters Ruled the Air]

A lot more had to happen prior, and that is what this article is all about. It will also serve as a reference to articles you’ve been reading by John Schneider that are part of this “Radio at 100” series and are focusing on specific topics in more depth.

Roots of Radio

Most historians credit Guglielmo Giovanni Maria Marconi — inspired by reading about Heinrich Hertz and his work in demonstrating the existence of electromagnetic radiation — with having “invented” radio around 1895.

Truth be known, young Signor Marconi, barely 21, didn’t really invent anything new. He combined the inventions of several others (spark coil, detector, batteries, etc.) to create a wireless signaling system.

As he was the first to do this and promote his accomplishment (through his English mother’s connections), he got credit — and a share in the 1909 Nobel prize in physics — for putting together this rudimentary communications system. Later, claims to priority were made by or on behalf of others including Tesla, Popov, Lodge and Bose. But they were less well-connected and without the support and machinations of a doting mother.

None of these individuals invented broadcasting. Their concerns centered around investigations of electromagnetic radiation, detecting lightning discharges, remotely igniting gunpowder, wireless transmission of electrical power, or in the case of Marconi creating a means of wireless signaling and communication.

Broadcasting of speech and music to the masses wirelessly would be the provenance of others and would have to wait a decade or so.

False Starts

Most notable of these was Reginald Aubrey Fessenden who, early in the 20th century, was driven by an obsession of sorts to move radio away from the endless streams of “dits and dahs” being spewed out by gigantic high-voltage spark coils — really artificial lightning machines — and used more or less exclusively for communication between ships and corresponding land-based stations. (By that time, there was also a sizable community of amateurs of all ages who were interested in provoking the “luminiferous Ether” through which these “Hertzian waves” were thought to travel.)

Fessenden was the first to realize the requirement for a smoothly changing (sinusoidal) carrier wave upon which to impress speech and music, and also the potential for wirelessly transmitting such intelligence to the masses untrained in the art of copying Morse Code.

He succeeded well enough in his efforts in late 1906 to demonstrate “radiotelephony” to a handful of witnesses, including a couple of Associated Press reporters, late in the afternoon of Friday, Dec. 21, that year. (Fessenden would much later in his life claim to have put together a real “broadcast” a couple of days later to entertain shipboard and land station wireless operators, but this wonderful Christmas Eve event has never been substantiated.)

While Fessenden certainly had the dream — even providing a typed “handout” about the potential to transmit news and entertainment to large numbers of “listeners-in” to attendees at his Dec. 21 demonstration — he lacked the drive to follow through on this initiative, leaving it to others.

One of these, Lee de Forest — who invented the first really useful electronic amplifying device and would later assume the title of “father of radio” —  did follow through a few days after Fessenden’s demo by putting speech and music on the air in and around New York City in late December 1906, and carrying this work on into 1907 and beyond. De Forest even broadcast music created by a primitive keyboard synthesizer, the Telharmonium, and live performances from the stage of the New York Metropolitan Opera House.

In San Jose, Calif., and a bit later out of the gate, Charles “Doc” Herrold was smitten by the concept of providing entertainment wirelessly to the masses, first experimenting around 1909 with a system of wireless telephony similar to that used by de Forest and starting up a regular broadcasting initiative in 1912.

However, in both cases (and on both coasts), outside of the amateur radio community and a few members of the professional ship-to-shore users of radio, there wasn’t really much of a listening audience, and apparently neither de Forest nor Herrold was sufficiently interested in promoting their broadcasting efforts to achieve “buy-in” from the general public.

They preferred instead to focus on the creation of radio-related inventions and patents and, in the case of Herrold, operating a school to train prospective “radiomen” in the fundamentals of the art.

Truth be told, due to the rather poor audio fidelity that was achievable via the transmission and modulation technology used by de Forest and Herrold — they both employed transmitters driven by a hissing electric arc —  it is doubtful that even with a lot of money spent on promotion, the masses would have been attracted much beyond the initial novelty of the thing.

Inventing the Technology

So, assuming that Westinghouse’s Dr. Frank Conrad did possess the requisite technical savvy and imagination to envision and bring into being radio broadcasting, it’s obvious that several things had to happen to move from the high-frequency alternator of Fessenden and the “arcphone” technology employed by de Forest and Herrold.

The Marconi U.S. 1904 patent describing the use of tuned or resonant circuits in transmitter and receiver circuitry. It followed the issuance of the famous “four sevens” U.K. patent in England in 1901; however, this was challenged by former Marconi employee Oliver Lodge, and the U.S. patent was later ruled invalid, with the court citing the prior art of Nikola Tesla.

There was no quantum leap here. A number of principles had to be established, discoveries made and inventions perfected before a satisfactory means for transmitting speech and music burst upon the global scene in the early 1920s.

Foremost was the setting down of the fundamental equations and relationships governing all electromagnetic radiation by James Clerk Maxwell, and the experimentation and proof positive of the existence of this invisible energy a few years later by Hertz.

Both of these milestone events were necessary for radio of any sort to move forward; however, in themselves, they did not lead directly to a system for broadcasting.

One of the seminal inventions, or principles, was that of resonant, or tuned, circuits. For this, the Marconi company has to be given some amount of credit, as a rather famous British patent (No. 7,777 and referred to as “the four sevens”) was awarded to that firm in 1901.

This patent (“Improvements in Apparatus for Wireless Telegraphy”) and its U.S. counterpart no. 763,772, issued in 1904, describe the use of tuned circuitry and the transmitter and receiver to allow them to “syntonize” or operate on the same frequency.

This invention was driven by the need to reduce interference between spark radiotelegraph stations, which, prior to the introduction of such technology, radiated very broad signals (spread-spectrum?) with tuning set only by whatever stray capacitance to ground and antenna/transmission line inductance existed at a particular installation.

(Interestingly, Oliver Lodge, who had been employed by Marconi and experimented along these lines, challenged Marconi’s priority in making such a discovery. Also, the U.S. version of the patent was declared invalid in 1943, with credit being given to Tesla for prior art.)

Lee de Forest’s 1908 “audion” triode patent.

Regardless of who invented tuned circuity achieved through use of discrete components, it was a fundamental step on the path to broadcasting.

Another key component was something that Marconi and his company couldn’t provide: a means for generation of a continuous high-frequency oscillation to serve as a “carrier wave” for transmission of speech and music. (Marconi’s spark-driven wireless telegraphy operated in bursts of electromagnetic energy, referred to as a “damped wave” or an oscillation that trailed off in intensity over time.)

Fessenden appears to have been first to recognize the unsuitability of damped waves for transmission of speech and music, initially working to perfect a spark transmitter with an extremely fast “make-and-break” interval so as to try and ameliorate this shortcoming. He did build a working model and demonstrated it in late 1900, transmitting a raspy, but intelligible, representation of human speech for a distance of about a mile.

Fessenden quickly realized that spark was a dead-end technology for his application and experimented for a while with Poulsen’s arc-driven oscillator before moving on the concept of using a high-frequency AC generator (alternator) to create a continuous wave without the “sizzle” associated with arc.

Charles “Doc” Herrold (standing, center) at his San Jose, Calif., combination radio school and broadcast station. The turntable (phonograph) and microphone (telephone carbon “transmitter”) are clearly visible on the table at the left.

After several years, and a lot of pressure exerted on the General Electric Co. to develop a high-frequency alternator, he did publicly demonstrate successful transmission of speech and recorded music on the afternoon of Dec. 21, 1906.

However, there is a limit as to how fast an alternator’s armature can spin without flying apart. This limited operation of such mechanical sources of RF to very long wavelengths that aren’t really practical for general broadcasting purposes (VLF and LF portions of the spectrum).

Audio modulation is also very difficult to achieve with such rotating machine technology. (Fessenden simply inserted a specially designed carbon microphone in series with the transmission line feeding the antenna. The mic’s resistance varied with the audio reaching it, and this in turn varied the transmission line current, achieving amplitude modulation of a sort. He admitted at his Dec. 21 demo that this scheme provided a modulation depth of no more than about 5%.)

Despite this rather large advance in technology, practical broadcasting had hit another dead end of sorts, awaiting a more practical means for generation of a continuous wave.

This came almost by accident in late 1906, about the time that Fessenden was performing his public demo of speech and music, when de Forest hit upon the idea of an electronic amplifying device when trying to develop a detector that didn’t infringe on previous inventions. It was not long before de Forest and others discovered that his crude three-element vacuum tube could also function as an oscillator. This device, after a lot of refinement by licensees GE and AT&T, supplied another key ingredient essential for the birth of broadcasting.

Raymond Heising’s patent for achieving amplitude modulation. This development marked a quantum jump of sorts in methodology for effectively impressing audio on a carrier wave.

Aside from a practical radio detector — which now existed in several forms (electrolytic, crystal and vacuum tube) — the only other missing ingredient was a reasonably efficient methodology for modulating audio onto a carrier wave. This was supplied by a Western Electric engineer, Raymond A Heising, in the form of his “constant current modulation technique.”

While not perfect in terms of efficiency or modulation depth, it did provide a relatively simple way to impress audio intelligence onto a carrier, and was a quantum leap from the methodology employed by Fessenden and others in broadcasting’s “pre-history.”

While these elements — tuned circuitry, a practical source of continuous waves and an audio modulating scheme with reasonable efficiency — which were all available by the mid- or late-1910s, the world would still have to wait a little longer for the birth of broadcasting.

A major complicating factor had arisen: The Great War (1914–1918). With America’s entry into the fighting in the spring of 1917, much of the work on radio research and development was halted, and an executive order in April from Pres. Woodrow Wilson led to the dismantling of private transmitting and receiving equipment.

Radio went to war for the first time, and research in this area was basically limited to the production of practical apparatus for use in battlefield communication.

Broadcasting would have to wait a little longer.

NEXT: Radio broadcasting takes to the air.

 

The post They Set the Stage for the Birth of Radio appeared first on Radio World.

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Scott Gerenser is a senior software engineer at Wheatstone Corp. and Andy Calvanese is vice president of technology.

Scott Gerenser

One term popping up more and more in the cloud space is “containerization.” If you’re-paying attention to the trends in cloud computing, you’ve probably heard about it, or at least about the most popular container platform, Docker.

Containerization is becoming a popular alternative to virtualization for running many different applications on a single machine or cloud instance. It has many of the benefits of virtualization but without some of the downsides, which makes it useful for transitioning from a fixed-location studio to a virtual operation.

[Read: “Don’t Be Afraid of AoIP”]

Whereas virtualization involves emulating an entire machine, including the hardware and operating system, containerization involves encapsulating one or more applications and supporting files (so called “userspace” in Linux lingo) into containers that can then run on top of a single common operating system (usually Linux).

BENEFITS

For example, in a virtualization scenario, you might have a server running VMWare ESXi hypervisor software, upon which are four Ubuntu Linux virtual machines for Service X, two Red Hat Linux VMs for Service Y, and a couple of Windows 10 Server VMs to handle any Windows applications you have.

Using virtualization this way still provides big benefits over maintaining multiple physical machines. Administration is easier. Spinning up a new server or changing configurations of the individual VMs is much easier than tinkering with hardware. Communication between the VMs is very fast and efficient.

The downside, as compared to containerization, is the relatively large overhead associated with virtualization. This is because each VM is running a complete OS kernel, each with their own dedicated memory and each using up a percentage of your CPU to mostly do a lot of the same things.

Containerization, by comparison, also allows the running of a number of different isolated services on one machine, but within containers rather than full virtual machines.

Conceptually, a container can be thought of as a very lightweight, resource efficient VM. One container could host WheatNet-IP audio drivers and audio playback software, while another could host the station automation system, each totally isolated yet run off the same OS kernel.

Because each container operates independently of the others, you can avoid unintended interactions between software components and eliminate a single point of failure. Each application or container communicates with the others only through their defined APIs.

The container virtualization layer is extremely flexible and can scale up to meet rising demand for any of the services. Once you define what services are running in one or more containers, it’s possible to move those containerized services between on-premise machines and the public cloud. This allows you to more easily scale services locally at your regional studio or in a cloud provider such as AWS or Azure.

And unlike with virtualization, there is no extra supervisory overhead to contend for resources, and containerization platforms are even able to run on top of virtualization platforms.

This last point is critical for long-term planning, since Amazon, Microsoft and other public cloud providers are already running hypervisor software on their cloud instances. Attempting to add your own VM hypervisor on top of a cloud provider’s machine instance may work poorly, or not at all. Containers, by contrast, work well on just about all the cloud providers and instance types. Most providers even offer tools to make it easy to manage and coordinate your containers running in their cloud.

Fundamentally, containerization and virtualization are two different ways of doing the same thing. Having several containers running separate services pushed up to a cloud won’t solve issues such as communication latency over the internet, but it will offer some added security protection and flexibility, and let you allocate resources more efficiently, which is the point of the cloud, after all.

 

The post Containerization as an Alternative to Virtualization appeared first on Radio World.

Sixteen stations in Arkansas, Louisiana and Mississippi are on notice that if they don’t file for license renewal by June 1, their licenses will expire.

The FCC released the list of stations that were supposed to have filed by early February. The list includes several LPFM stations and one translators.

[Read: FCC Deletes Call Signs of Two California FM Stations]

The stations and licensees are:
KZTD(AM), Cabot, Ark., Emanuel Carrera
KPWH(LP), Jonesboro, Ark., Powerhouse Ministries
KHEE(LP), Magee, Ark., Desha County Community Radio Inc.
KTPV(LP), Prairie Grove, Ark., Foundation for The Preservation of The Individual
KLSP(FM), Angola, La., Louisiana State Penitentiary
KVDP(FM), Dry Prong, La., Dry Prong Educational Broadcasting Foundation Inc.
KWRJ(LP), Elton, La., Coushatta Tribe of Louisiana
KLIC(AM), Monroe, La., WOO2 Communications LLC
KCRJ(LP), Monroe, La., IBC Ministries Inc.
K219DB(FX), New Iberia, La., Bible Broadcasting Network Inc.
WORV(AM), Hattiesburg, Miss., Circuit Broadcasting Co.
WKRA(AM), Holly Springs, Miss., Billy R. Autry
WKRA(FM), Holly Springs, Miss., Billy R. Autry
KOUI(FM), Louisville, Miss. South Central Oklahoma Christian Broadcasting Inc.
WMOX(AM), Meridian, Miss. Magnolia State Broadcasting Inc.
WNNN(LP), Noxapater, Miss., Mt. Vernon Missionary Baptist Church

Download the notice here.

 

The post FCC Lists Stations at Risk of Losing Licenses appeared first on Radio World.

Satellite program distribution network operator Skyview Networks is highlighting ad campaign customization options inherent in its receivers as a way of approaching the varying levels of economic activity across the country.

[Read: Twins Pair Up With Skyview Networks]

According to the company these include: targeting individual messages to a particular region, market or states; target different messages in the company’s lineup of news, music and sports programs; air multiple advertisements to a specific market, state or region

A release explained, “advertisers can benefit from tailored campaigns that target customers not only in the reopened regions of the economy, but down to the individual market level.”

 

The post Skyview Networks Pushes Ad Tailored Campaigns appeared first on Radio World.

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Public Notice Announcing Filing Dates for Comments and Reply Comments to NPRM Regarding the Rules Governing the Use by Broadcast Stations of Distributed Transmission System Technologies

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