Radio World

The author is sales and business development manager for Ampegon Power Electronics AG.

TURGI, Switzerland—Following this year’s IBC exhibition in Amsterdam in September it became clear that, despite our best efforts, many in the radio community are still in the dark about what has recently happened at Ampegon; a long-term supplier of transmitters and equipment to shortwave and medium-wave broadcasters worldwide.

Simon Keens

Rumors have abounded regarding the health of the company and we hope today to clarify the situation here

Late in 2018, Ampegon’s former investment capital owners decided to sell Ampegon. This had been planned since 2012 when they acquired the company following the restructuring of the Thomson group. Since you never completely fuel a car that you’re just about to sell, Ampegon was instructed to minimize further unnecessary investment in marketing, which is why customer visits and conference attendance fell to a historic low. This left the company to focus solely on completing projects prior to transfer of ownership.

In the end, the process of selling the company took longer than anticipated, meaning that some projects were delayed and left unfinished at the point of sale. Additionally, the former owners proceeded to sell the four parts of Ampegon separately: The shortwave transmitter, power supply and control system section in Switzerland, the antenna division in Ludwigshafen, the former Transradio medium-wave transmitter factory based in Berlin, and the industrial pulsed power supply specialists in Dortmund, all in Germany. This necessitated a break-up of the group, with assets from each company being sold off individually. It inevitably caused disruption to normal operations.

The shortwave transmitter business, along with the staff, tools, and stock material has now been bought by a new Swiss company: Ampegon Power Electronics AG. This company was formed specifically to complete the transaction with Ampegon AG, and took over all IP and technology rights, branding (including the name and logo of Ampegon), website and contact details.

Telephone numbers and email addresses for contacts in sales, engineering and purchasing are essentially unchanged. Today (at time of writing) we understand that Ampegon AG exists only as a company on paper, with practically all staff moved over to Ampegon Power Electronics AG. Similarly, staff and assets from Ampegon Antenna Systems GmbH and AM Broadcast GmbH have been sold to Cestron International and now continue their respective businesses under the name Elsyscom.

We hope that Ampegon Power Electronics and Cestron/Elsyscom work closely moving forward, once the necessary agreements are in place; providing the integrated transmitter/antenna systems that have been so successful in the past. Research Instruments has acquired the industrial pulsed power team in Dortmund, although this is not considered significant to the broadcast community.

A 4/4 rotatable directional antenna supplied by former Ampegon Antenna Systems GmbH of Ludwigshafen, Germany.

Unfortunately, a number of Ampegon’s customers were left with partially completed projects when our former owners withdrew their support in preparation for selling the company.

The company’s former staff — who remained in post even though they went unpaid for some months — regret the inconvenience caused, but are currently working hard under Ampegon Power Electronics to resolve the issues arising from being a new company, and not the legal successor of Ampegon AG. This has meant that contracts must be transf

erred, warranties reviewed and all other previous agreements with our customers and colleagues in the community must be annulled and renewed.

Looking ahead, however, the core skills of Ampegon remain in place to support the broadcast community over the coming years and decades. By and large Ampegon’s engineers and employees are the same people in the same place doing the same thing, but now with an industrial group behind them rather than a capital investment company. We are looking forward to continuing work with our friends and colleagues in the community as we look at new revolutions in broadcasting such as Digital Radio Mondiale, data communications and energy efficiency in the future.

Development of Ampegon’s second-generation Class A/B solid-state transmitters is practically complete, with production of 1.5 kW – 25 kW versions, capable of broadcasting between 3 MHz to 30 MHz, ramping up. A third-generation solution offering significantly greater energy efficiency is approaching prototype stage.

A shortwave transmitter supplied by Ampegon, now Ampegon Power Electronics AG, of Switzerland.

[Read: Solving the Medium-Wave Problem]

Simultaneously, Ampegon has developed control system upgrades to support users of older-generation tube transmitters having difficulty sourcing spares, and also to provide opportunities to retrofit older systems with new digital DRM broadcast capabilities. Of course, with touchscreen technology and innovative controls, such an upgrade makes these transmitters easier to use, simpler to maintain and safer than ever before. Of course, we are complimented by the requests to support over 20-year-old transmitters, since this is testimony to their reliability and value.

It is Ampegon’s hope to continue serving shortwave broadcasting long into the future. We see the unique capabilities of the technique, and the significant future opportunities presented by digital broadcasting with DRM. And who knows what other technologies may benefit from use of shortwave? Time will tell, and Ampegon intends to be there to support it.

For information, please see:

https://ampegon.com/download/pr_sale_assets_of_ampegon_ag_-_immediate_release.pdf

https://cestron.de/News

https://research-instruments.de/news-events/news-detail/13

 

 

The post What Exactly Happened to Ampegon? appeared first on Radio World.

As he gratefully accepted an award from New York State Broadcasters Association, Federal Communications Commissioner Michael O’Rielly noted — wryly — the irony of the moment.

The award, for New Yorker of the Year, was being bestowed, he said, on a government bureaucrat “who never spent one day working at a broadcast station; who has never been closer to the news industry than when he had a paper route.” Those were some of the remarks made by O’Rielly — undoubtedly to laughs from the room full of broadcasters — during a luncheon with the NYSBA during its Broadcast Leadership and Hall Of Fame Luncheon on Oct. 17 in New York City.

[Read: O’Rielly: First Amendment Rights Worthy of Strongest Defenses]

“You should know that, when David [Donovan, president of NYSBA] called to congratulate me for being selected as New York Broadcasters New Yorker of the Year, I suggested he was way off base,” O’Rielly told the crowd. “In my mind, I stand before you as someone completely unworthy of this honor. Let’s face it: you are looking at a short, overweight, government bureaucrat … whose claim to FCC fame includes successfully allowing broadcast stations to close up shop,” (albeit, he said, as part of the much-lauded elimination of the FCC’s long-standing Main Studio Rule).

“[While] there are far more deserving individuals from this amazing state,” he said. “But…not being on the selection committee myself, I happily accept this award.”

O’Rielly, a native New Yorker from the western part of the state, said broadcasting provided a “wonderful foundation of fulsome life experiences” that have been enormously valuable throughout his professional career. He was born and raised in a small city on the Erie Canal just outside Buffalo, N.Y., which is home to hearty, hardworking individuals that — as he said in his confirmation hearing back in 2013 — “accept the hard winter weather and lack of sun as a badge of honor.” All across the State of New York, O’Rielly said, people are smart, gritty realists who tend to tell it as it is. “Throw into that mix some challenging weather from time to time, and you have the formula for some really unique individuals that tend to do well in our fairly complex society,” he said.

Local broadcasting was a key part of his early education, he said, as local news, sports coverage and children’s programming fed some of his earliest interests. During his six-year-long tenure at the commission, O’Rielly said he has attempted to distinguish himself as someone who listens attentively to the problems and issues facing broadcasters and tries to find workable solutions, from local ones pirate radio to broader ones like the seismic shift in the video marketplace.

“Part of my focus has been to reduce the overall regulatory burden on broadcasters, as is demanded by the FCC,” he said. “This means eliminating any and all unnecessary requirements that impinge on broadcasters’ ability to serve their local communities. Your government should not mandate obligations that impose undue costs and require inordinate time to comply when a regulation has far outlived its usefulness in the modern marketplace.”

O’Rielly told the organization that the good news for the broadcast industry is that there are important and vibrant opportunities ahead. “While the competitive marketplace may change around you and technology may continue to present challenges, you provide real value to the American public,” he said.

For local radio in particular, “your role in the community has never been more important, especially with the demise of so many newspapers.”

He touched on personal tragedy during the event by saying that a recent death in his family of his brother-in-law put a somber note on his appearance at the event.

But he closed by saying that this award would only serve to make him “work harder, smarter and longer to ensure that the American people are getting their money’s worth from the FCC.”

As president of the NYSBA, Donovan said that O’Rielly stands apart as one of the outstanding commissioners in the history of the FCC.  “He studies an issue in depth and then makes a principled decision,” Donovan said, saying O’Rielly has been a leader on a number of issues affecting New York broadcasters, including his championing of increased enforcement against illegal pirate radio operations.

Prior to being nominated by Pres. Barack Obama in 2013, O’Rielly served in key positions in the U.S. Senate, including as policy advisor in the Office of the Senate Republican Whip and as a professional staff member on the Committee on Energy and Commerce for the House.

 

The post NYSBA Honors Native Son O’Rielly as New Yorker of the Year appeared first on Radio World.

On Oct. 17 Pakistan Broadcasting Corp. began DRM for FM test transmissions on a consumer receiver.

According to the DRM consortium, the public broadcaster is sending the DRM signal from its headquarters in Islamabad using a low power of 75 W. The signal reportedly reaches an area of between 5–10 kilometers around the city.

Pictured from left to right are Ghulam Mujaddid (PBC), Roman Afroz (HEDRA), Peter Timmons (GatesAir), Kamran Saeed and Nauman Jarral (PBC).

Broadcasting on 101.6 MHz and pushing from a single FM transmitter, the receiver auto tunes into three services — FM101 (entertainment), Dhanak (music) and Saut-ul-quran (religious). Additional text information including Journaline is also available.

For the trial, the PBC is using a GatesAir 1 kW Flexiva transmitter and Exgine card; an RF Mondial DRM Content Server and DRM+ professional receiver; a Label Italy Bay antenna system; and a Gospell consumer DRM receiver.

“The Gospell receiver, which originally worked on AM is now working on FM too,” noted DRM Chair Ruxandra Obreja. “This is a great step forward as it shows there can also be a commercial solution for DRM in FM. A similar test, which started this summer and continues in St. Petersburg, Russia, is also using a Gospell receiver.”

[Read: Solving the Medium-Wave Problem]

Hedra Technology, Fraunhofer IIS and the DRM international Consortium are collaborating on the project, which is managed by PBC specialists Kamran Saeed, director engineering; Ali Zia Abbasi, controller engineering and chairman DRM steering committee; Ghulam Mujaddid, engineering manager and DRM steering committee member; and Yasir Mustafa, engineering manager and DRM steering committee member.

DRM adds that in addition to Russia, Pakistan joins Indonesia and South Africa. Both of these countries have recently demonstrated DRM in the FM band as well.

 

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Technical broadcast operator BCAST has debuted a new platform that is meant to help small and medium broadcasters implement the DAB+ standard, named DABCAST.

DABCAST supports the range of functionalities needed for digital radio creation from studio to broadcasting. This is done through its Virtual Studio web app, where multimedia content can be created and managed.

The cloud application MUX processes the radio streams and converts them into the appropriate format for DAB+; while the TX transmitter, a physical device that receives signal from the cloud, modulates it for final broadcast. The signal from the air is then analyzed by the DAB+ monitoring probe.

More information about DABCAST can be found here.

 

 

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DABCAST Designed to Simplify DAB+ Implementation appeared first on Radio World.

Software developer and digital audio hardware maker Steinberg is expanding its line of portable and rackmountable digital audio interfaces with the UR-C line of USB C interfaces.

The UR-C family will initially offer two- (UR22C) and four-preamp (UR44C) models with a rackmountable eight-preamp (UR816C) model following. There’s also a “Recording Pack” bundle featuring the UR22C.

[Check Out More Products at Radio World’s Products Section]

All models offer 32-bit/192 kHz conversion, 48V phantom power, Neutrik analog combo connectors, Hi-Z switch, MIDI I/O, and software including REV-X Reverb, Channel Strip, Guitar Amp Classics, dspMixFx, Cubase AI and Cubasis LE. All are Windows-, Mac- and iOS-compatible.

The UR816C also offers word clock ADAT I/O for those with legacy equipment.

There is also a UR22C Recording Pack bundle version featuring all of the previously listed plus the ST-M01 condenser microphone (with cable) and ST-H01 headphones along with WaveLab LE software.

UR22C: $239; UR44C: $439; UR816C: $789; and UR22C Recording Pack: $439.

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“Best of Show Up Close” is a series about participants in Radio World’s annual Best of Show at NAB Awards program.

Broadcast Partners nominated Smart Processing, a module of the company’s Smart Radio. SmartRadio is a cloud-based radio automation platform. We asked Rene van de Kolk, manager, R&D, Broadcast Partners, to explain.

Radio World: Smart Processing was a feature of your booth at NAB. For those who couldn’t attend, what is the product and what are its targeted uses?

Rene van de Kolk: Smart Processing provides three different cloud-based modulation-processing solutions: Basic, Medium and High-End. Smart Processing uses Orban back-end software solutions for this.

Smart Processing is a part of Broadcast Partners’ SmartRadio platform, and can be used in this full cloud- and web-based platform by integrating with the Smart Playout possibilities by using AoIP protocols. Smart Processing is hybrid, and thus also standalone, available outside the SmartRadio platform and can easily be connected with other existing playout services.

[Read: Best of Show Up Close: MaxxKonnect Wireless]

Smart Processing delivers excellent Orban modulation presets and a unique sound, with all of the presets that Orban has been offering the market or years.

Smart Processing is for the increasing online and digital radio market. Media companies all over the world are launching multiple subchannels as additions to their main brand. These can be for shorter periods or select certain seasonal theme such as summer, Christmas or Valentine’s Day or used for longer periods. Branded radio channels can be launched easily without investing in hardware units or upgrading server farms. So targeted users are media companies, radio stations and publishers who launch multiple online or digital (DAB+) radio stations.

RW: You describe SmartRadio as “radio as a service.” How does it differ from other offerings in this product class?

Van de Kolk: SmartRadio is 100% cloud- and web-based. All functionality can be used in a Chrome browser. Creating and producing content can be done easily, anywhere, anytime or any place. The only requirement is connectivity. SmartRadio is a beginning-to-end solution: using Smart Database with multiple metadata options that can be used for playout, cloud-based voice tracking, cloud-based multitrack editing without delay and pushed through Smart Processing to be published on multiple platforms online or digital radio, for example.

For online, the best CDN network from the Netherlands is fully integrated. In addition, the specially developed headend for DAB+ services, aXemble, is as-a-service available in SmartRadio. With these services our goal is to help existing and new media-organisations to innovate without the need of heavy investment. All services are available as-a-service with specific pricing per module. For the past two years, we developed this platform with eight developers at Broadcast Partners.

At NAB, IBC, Salon de Radio and Radiodays Europe we retrieved feedback from the market to develop customized solutions. This is possible because all services (also a full Smart Scheduler, or Smart Commercial Scheduler) are developed by thinking in micro-services terms. This means hybrid and flexible development in the most modern program code-language. Connections with other innovative parties is possible by using our API. In SmartRadio, connections with VMix, Beats Newsportal and Radio Manager are already made.

RW: What does SmartRadio cost? Is it available now?

Van de Kolk: SmartRadio is fully hybrid and can be used in all preferred setups. Licenses can be used as-a-service per month/radio channel and are customizable for one channel for one month in an existing cloud environment. This includes the Smart Database (including cloud-and web-based metadata-editor), Smart-Format Scheduler and Smart Non Stop Player (including four-channel cloud- and web-based editor). SmartRadio is available in public cloud-based environments but can also be installed in private cloud-based environments. All preferred connections and add-ons for services will increase the monthly fee.

Smart Processing, is also available. Licensing/pricing is based on an as-a-service model. For one radio station you pay the required service fee per month based on your preferences.

RW: More generally, what do you see as the most important trends or changes happening these days in how broadcasters are using the cloud?

Van de Kolk: Using AoIP solutions from companies such as Lawo, Ravenna, Telos Alliance and Dante [Audinate] but also virtualized complete productions environments. That’s also why our software-defined solutions are integrated in the different mixing console platforms, to provide a full screen-based user-experience in the future. By publishing multichannel, on different platforms, hybrid software solutions are important and are more flexible in terms of updates than ever before in the past. Relevant data from listeners is key if you want to stay relevant in the future, so collecting data and receiving clear insights is also a main trend, in my opinion.

 RW: What else should we know about this product or your company’s recent offerings?

Van de Kolk: Different modules are available. Innovation can therefore be done in different projects or trajectories. Our Smart Scheduler, is a full option format planner and can be connected to all big existing solutions when they are able to connect on API. A very impressive web-based user-experience in defining your format is possible.

The Future Best of Show Awards program honors and helps promote outstanding new products exhibited at industry conventions like the spring NAB Show. Exhibitors pay a fee to enter; not all entries win. Watch for more coverage of participating products soon. To learn about all of the nominees and winners, read the 2019 Best of Show Program Guide.

 

The post Best of Show Up Close: Broadcast Partners Smart Processing appeared first on Radio World.

Marshall’s microphone and accessories division MXL has packaged together some of its offerings into a podcasting bundle.

Called APS Podcasting Bundle, it consists of MXL’s BCD-1 dynamic broadcast microphone; its companion BCD-Stand; and the Mic Mate Pro XLR-USB digital audio interface/adaptor.

The heart of the bundle is the top-address BCD-1 microphone. It has a dynamic element, internal shockmount and tuned grille to combat unwanted noises. Its design aims to also have high side noise rejection.

The Mic Mate Pro offers gain and headphone controls with 16-bit 44.1/48 kHz conversion.

MXL Microphones Sales Director Trevor Fedele said, “In the last decade, podcasts have seen a huge surge in popularity, and our APS Podcasting Bundle provides the quality tools needed for those in this market. … With the creation of the APS Podcasting Bundle, studio-quality broadcasting technology is now within the reach of every recording enthusiast.”

 

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Eugenio Lateana, head of research and development for EuroDAB Italia (left); Federica Gentile, RTL 102.5 presenter (center); and Mary Hockaday, controller of BBC World Service English, announce the Italian launch of BBC World Service on the EuroDAB Italia multiplex.

MILAN — BBC World Service and EuroDAB Italia have entered into an agreement to broadcast the global network’s rich mix of BBC News, documentaries, business, sports, arts and science programs as a new service included in EuroDAB Italia’s DAB+ multiplex.

On Oct 9, Mary Hockaday, controller of BBC World Service English, and Lorenzo Suraci, president of EuroDAB Italia, officially launched the new service and presented the vision behind this agreement and their expectations for the future.

TRUSTED BRANDS

Mary Hockaday (left) and Lorenzo Suraci, EuroDAB Italia present, presented the vision behind the new agreement and their future expectations.

Although about 30% of Italians can speak some English, including a large part of the younger generation, no English-speaking service is at present broadcast in Italy on regular basis.

“We live in a world with an infinite number of information sources and making a choice among those sources often makes us feel confused,” Hockaday said. “It’s wonderful to have such a diversity, but in this surrounding noise actually many people seek trusted brands, and they seek media and information they can trust.”

According to Hockaday, trust is at the heart of what BBC and BBC World Service can offer, including “accurate and impartial means and good information.”

In a world where everyone can have on his or her smartphone a multitude of headlines and news from all over the world and from as many different sources, Hockaday emphasized how hard the BBC World Service works to provide their listeners with a rich editorial mix with news but also information on business, sports, culture, technology, politics and stories.

DIGITAL CAPABILITY

The BBC World Service logo displayed on a visual-capable DAB receiver tuned to the EuroDAB Italia multiplex.

“Whenever you turn on the radio, you will always find something engaging, informing, delighting and feeding curiosity within our offer ,” she concluded.

“We are very proud that BBC World Service choose the EuroDAB digital network to broadcast its content in Italy,” added Suraci. “It improves and extends the offer of the contents of our bouquet and helps the radio, in general, in an increasingly global world.”

DAB+ broadcasts are already available to 80% of Italians and that percentage is set to grow due to the Italian legislative requirement for all radios sold in Italy from Jan. 1 2020 to have digital capability.

[Read: Does 5G Make Sense for Radio?]

In Italy, 46% of new cars are now sold with DAB+ as standard, and according to the Italian media regulator AGCOM, radio is the second most frequently used media after television, while 68% of the population listens to radio for an average of 2.5 hours per day.

 

The post EuroDAB Italia Begins Airing BBC World Service appeared first on Radio World.

RW Editor in Chief Paul McLane prepares for his time in the almost-Broadway lights with his fellow actors, Robert Alvey as Mark Twain and P.J. Ochlan as Nikola Tesla. They’ll be appearing in a special performance of “An Intimate Evening with Tesla and Twain” for an AES Show audience, Wednesday.

The post Tesla, Twain and McLane appeared first on Radio World.

Would you like to get an early start on one of the industry’s biggest annual trade shows? Come along for a free webinar from Radio World International, hosted by editors Marguerite Clark and Paul McLane, on Sept. 4 at 3:30 p.m. CET.

Marguerite and Paul will provide a peek at new products they expect to create buzz; explore the newest digital radio sessions; and share what they’re hearing from our industry’s leaders about important tech developments and standards.

IBC is a huge and fabulous event, but it can also be daunting. With more than 55,000 attendees expected and more than 1,700 exhibitors covering 15 halls, the job of getting the most out of IBC2019 requires a lot of planning. Radio World International will help you learn about key pieces and products the show selected with the radio reader in mind.

The webinar was sponsored by: Comrex, Digigram, ENCO, GatesAir, Rohde & Schwarz, StreamGuys, The Telos Alliance, Veritone and Wheatstone.

NOW AVAILABLE HERE ON DEMAND

 

The post 15 Things You Can’t Miss at IBC2019 appeared first on Radio World.

Find your modulation “sweet spot.” Build a solid-state mic preamp. Plan a visit to the WBA Broadcasters Clinic. Create a YouTube channel. And take a look inside the new studios of America’s top-billing radio station.

BROADCAST LAW
Radio Eyes Advantages of Deregulation

With the commission backing off numerous requirements, how will broadcast ownership groups respond?

FACILITY PROFILE
Inside the Glass-Enclosed Nerve Center

Two dozen photos from Radio World’s recent video webcast tour of WTOP in Washington.

ALSO IN THIS ISSUE:

• Deter Stinging Insects at the Transmitter Site
• “THAT Thing” — A Solid-State Mic Preamp Project
• National VOA Museum Asks for Your Support

 

The post Inside the October 9th Issue of Radio World appeared first on Radio World.

“Today, wiring changes are done with a mouse, making and breaking crosspoints in software.” If you are nodding in agreement, RW Engineering Extra is for you! Find out who said it by browsing your latest issue.

DIGITAL RADIO
Upgrading an AM to All-Digital: Why, How and Lessons Learned

Dave Kolesar and Mike Raide update you on the WWFD project.

YOUR CAREER
What Does “Value Engineering” Mean to You?

Sometimes, plans need to be adjusted to fit the available dollars.

ALSO IN THIS ISSUE:

• What Does a Broadcast Engineer Do, Anyway?
• Phasing Quadrature Amplification
• Make the Most of Your Uncompressed Opportunities

 

The post Inside the Oct. 16 Issue of RWEE appeared first on Radio World.

A new round of construction permits are about to be up for auction.

The Media Bureau at the Federal Communications Commission introduced Auction 106, a new FM broadcast construction permit auction scheduled to commence on April 28, 2020.

Auction 106 will offer 130 construction permits for FM broadcast allotments, including 34 permits that were either defaulted upon or not sold or in earlier FCC auctions. The commission released a list of those vacant FM allotments, which include teeny Texas hamlets like Milano, Texas, population app. 400, as well as populous urban thoroughfares like Coalinga, Calif.

The bureau plans to follow the commission’s standard auction procedures — a multiple-round auction format that offers every construction permit bid at the same time and consists of successive bidding rounds in which qualified bidders can place bids on individual permits. Bidding usually remains open until bidding stops on all permits.

The auction will be conducted over the internet using the FCC auction bidding system, although bidders will also have the option of placing bids by phone. The bureau is also proposing to stop, slow or speed up the bidding if the process is proceeding at either a sluggish or a too rapid pace.

As in earlier auctions, the bureau proposes that applicants submit upfront payments as a prerequisite to becoming qualified to bid.

But before things kick off, the bureau and the Office of Economics and Analytics is seeking comment on a variety of auction-specific procedures relating to Auction 106 — including the proposed open bidding process, how much upfront payment should be required for each CP and the proposed opening bid amounts.

The price range for construction permits in Auction 106 vary wildly. On the low end sits permits for $750, such as ones in Wamsutter, Wy., and San Isidro, Texas. Compare that to the upfront payment of $100,000 — and the subsequent minimum opening bid of $100,000 — for a CP in California’s capital city of Sacramento. Mid-level bids include Huntington, Ore., for $45,000; West Rutland, Vt., for $25,000; and Gackle, N.D., for $15,000.

The initial bidding schedule will be announced one week before bidding starts via a public notice.

Comments on Auction 106 can be made through the FCC ECFS filing system using AU Docket No 19-290. The commission is also requesting that all comments be submitted electronically via the email auction106@fcc.gov.

FM broadcasters who have questions can reach out to the Audio Division within the Media Bureau at 1-202-418-2700.

 

The post New FM Construction Permit Auction Set for April 2020 appeared first on Radio World.

Mike Dosch will be leaving his role with equipment manufacturer Lawo and focusing full-time on his recently launched company Angry Audio.

Separately, his new company also will acquire the StudioHub wiring infrastructure line.

Dosch joined Lawo in 2014 with the title of director of virtual radio projects and later was named senior product manager radio. Prior, he was president of the Axia Audio division of the Telos Alliance; for 10 years before that he was with Pacific Research & Engineering, where he started as a console designer and worked his way up to VP and COO.

His company Angry Audio makes small problem-solving devices that it happily refers to as “gadgets and gizmos” targeting audio needs of the radio broadcast market. Products are sold through a number of U.S. and international dealers. Examples include the Guest Gizmo and the Bidirectional Balancing Gadget. A recently introduced Bluetooth Audio Gadget is intended to make it easier to put a smartphone on the air.

Separately, Angry Audio is acquiring the StudioHub product line, which it currently resells, from Radio Systems and developer Mike Sirkis.

“Angry Audio is buying StudioHub and will soon begin manufacturing the entire StudioHub line including cables, adapters, panels, breakout boxes and hubs, matching amplifiers, etc.,” Dosch told Radio World in an email.

[Related: “Radio Systems Turns a Business Page”]

“Additionally, we will be providing spare-parts support for products previously manufactured under the Radio Systems brand. Millennium consoles for example will soon be supported by Angry Audio. We’ve moved into a bigger space to accommodate the expanded product line and hope to have operations humming along next month.”

Dosch said his last day with Lawo will be next week.

The post Dosch to Devote Full-Time to Angry Audio appeared first on Radio World.

Tom Johnson and I were talking about pests.

Fig. 1: Eaves and overhangs at unmanned transmitter buildings can attract stinging insects.

We met at the Alabama Broadcasters Association and Larry Wilkins’ Engineering Day seminar; and as we talked about bugs infesting transmitter sites, Tom shared the picture in Fig. 1.

I don’t know many engineers who care for wasps, hornets or other flying, stinging insects. Tom’s photo is a great reminder to spray under eaves, and around door and window frames — any place that’s protected from the weather.

Unfortunately, with cold weather approaching, it’s not just vermin that seek shelter from the cold. An unoccupied transmitter building or AM antenna tuning unit is an ideal home for insects and rodents. Make sure it is sealed.

ATUs in particular can attract unwanted guests. If your ATU has a light fixture inside, wait til it’s dark and then  turn it on, then walk around the ATU looking for any escaping light (remember to look underneath, too; and also watch out for the “hot” tower). Any holes you spot, perhaps where bolts once held coils or other components, are “welcome signs” for insects, and usually the proper diameter for these insects to squeeze through. Plug those holes with RTV or caulk.

Remember also that before opening the ATU door, pause to watch whether stinging insects are flying around. They may have infested your enclosure already.

Check that entry panels or doors to the ATU also fit tight; again look for light leakage. Remember that field mice can squeeze through amazingly small crevices.

Tom waited till dark, then sprayed that nest and its occupants.

When I did contract work, a client was losing their satellite signal every day at dusk. I stood on a ladder and unscrewed the LNB. A swarm of angry wasps escaped the nest they built inside. How we didn’t get stung —  or break a leg, frantically jumping off the ladder — still amazes me.

As I mention in my Workbench sessions, a one-liter clear plastic water bottle fits nicely in the throat of a satellite feed horn and will prevent infestation. As for your building, a good spritz of wasp and hornet spray applied under all the overhangs on your building is good preventive maintenance.

 

* * *

 

San Francisco contract and project engineer Bill Ruck writes, “Been there, done that.” He was referring to the electrolytic capacitor woes we described recently.

Back around 1967, Bill learned about electrolytic capacitors working at a hi-fi store. Rule of thumb in those days was (1) if they’ve “puked their guts” by exploding, replace them; (2) if not, replace them anyway.

Since then, Bill’s experience is only worse. Many times he has traced spurious outputs of an FM exciter to the power supply oscillating and modulating the carrier.

Recently, Bill had two BE FX-30 exciters with that problem. The issue was traced to the FMO module. The problem was that the FMO is potted and to dig out the potting compound to replace the capacitors would take a lot of time and was no longer cost-effective. The group owning the exciter preferred to purchase a new exciter rather than put a lot of money into reconditioning something that was over 30 years old.

Bill adds a few more nuggets to consider:

1. Although high ESR (equivalent series resistance) doesn’t cause “ringing,” it does let an unstable amplifier oscillate. Furthermore, most three-terminal regulators can be defined as an “unstable amplifier” and will oscillate. Bill learned in his own home-built power supplies to put a 1 uF tantalum bead capacitor and a 0.1 uF ceramic disc capacitor as close to the regulator IC input pins as possible.

2. Always put in 105 degree C electrolytic capacitors. They’re slightly larger and slightly more expensive but they last a lot longer.

3. It takes the same effort to remove capacitors from a printed circuit board to measure them, than to just replace them. Yes, Bill can measure ESR and capacitance, but he does that only to confirm his suspicions, after putting in new low ESR 105 C replacement capacitors.

In summary, Bill writes that these days, component level repair is less cost-effective than during his misguided youth; but if you do make these repairs, replace!

 

* * *

 

Fig. 2: Find this DIY rat trap at the YouTube link in the text.

Our Workbench Malaysian connection, broadcast engineer Paul Sagi, found an interesting YouTube video that we’ll call “Curiosity Killed the Rat!” Here’s the link: https://m.youtube.com/watch?v=T-KJMM55A9A

Paul comments that it appears that clear box sealing tape was used to hold the grain, and the “ramps” appear to be floor tiles, placed so the underside faces up. Placing two ramps on opposing sides permit some rats to balance out each other, a single ramp may be better. Finally, for remote locations, Paul suggests affixing the ramp to the bucket, so it doesn’t fall.

My comment? I sure hope this isn’t someone’s transmitter site! That’s a lot of rats.

I also hope you’ll contribute to Workbench. You’ll help your fellow engineers and qualify for SBE recertification credit. Send Workbench tips and high-resolution photos to johnpbisset@gmail.com.

John Bisset has spent 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 Deter Stinging Insects at the Transmitter Site 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.

This week’s big news in community radio was all about layoffs at Pacifica radio station WBAI(FM) in New York and termination of its existing programming. The seriousness of the situation is a bellwether to conversations community media must have about relevance.

WBAI is certainly an iconic noncommercial radio station. It has hosted a veritable who’s who of cultural vanguards, especially in the 1960s. From Bob Dylan to Malcolm X, WBAI has been fondly remembered by fans for such history. Unfortunately, those glory days are long gone.

When I wrote for Radio World about the Empire State Realty Trust $3 million judgment against WBAI and Pacifica in 2017, matters were already quite dire. Pacifica audits noted a listener support decline between 2007 and 2017 in the millions. The California Attorney General’s Office and the Corporation for Public Broadcasting Inspector General launched probes in 2015 and 2011 respectively over management issues. WBAI had seen crashes in 2009 and 2013, and its internal strife, inability to make payroll and subsidization by other Pacifica outlets had been in public circulation for years. WBAI folks, a smart and interesting bunch to be sure, have long contended what may seem to be farfetched theories, from essentially embezzlement by its licensee to its owner kneecapping the station staff and volunteers for their liberal orientation and willingness to host marginal programming under the free speech banner.

[Read: Community Broadcaster: Changemakers]

Indeed, any publication that termed this week’s action stunning or a shock clearly must be excused for not paying attention to a crisis decades in the making.

Pushback to Pacifica’s decision was swift, including a state court intervening in the situation. However, it may be unclear how influential a New York court injunction to prevent layoffs and program changes will be. After all, Pacifica is a California nonprofit organization. The network’s payroll and WBAI’s federally assigned license (and thus programming placed on it) are both based far from said court’s jurisdiction. This story is developing.

Regardless of what happens to WBAI, the health of community radio as a whole is always a concern. What can stations learn from this issue?

As I conveyed to radio station WORT this week, community radio stations should always ask themselves about how they are truly listening to and serving local listeners with content they are passionate about and rely on. It is not difficult to figure out why WBAI, at 99.5 FM and in a city of eight million people and with one of the nation’s top median household incomes, could muster only 78,500 weekly listeners (according to Nielsen Audio) and not cover basic expenses. An old friend at Radio Research Consortium, noncommercial media’s data clearinghouse, once shared, listeners tell you what they think of your programming with their ears and wallets. Every station should track what their local fans think, and be responsive to area needs. That can be hard, given the many perspectives that are part of a station, but centering listener experiences with our stations must always be a priority.

Careful financial monitoring and adopting an approach to problems that sees them as a shared responsibility should also be a part of any station’s ethos. When tensions arise, the easy way out is to cast blame on others. Difficulties such as those experienced by the community radio space this week might have been averted with more swift, productive actions, and buy-in from everyone. All community stations might be wise to unify in times like these.

And finally, every station would be well served to take the lead in telling its story. In times of trouble, explaining one’s vision and where one hopes to be reassures listeners and tells donors you have a solution. Once a station loses control of its narrative, it is hard to regain credibility. Pacifica’s message posted on WBAI’s website is a start, in this instance.

Noncommercial radio observers may recall the WBAI move is not without precedent. In May, Humboldt State University shuttered its volunteer-based programming and laid off staff at KHSU in a bid to reorganize. A Humboldt State University advisory review identified a need for financial review of university investments, a realignment of the station’s operations and other issues for the licensee. One can hope WBAI’s reorganization is successful, and that all of community radio takes a cue from what’s happened to make the best media possible.

 

The post Community Broadcaster: A Cautionary Tale appeared first on Radio World.

The author is the head of technical and infrastructure department at German national public broadcaster Deutschlandradio.

The reception of radio programs with smartphones is becoming increasingly important for radio makers, particularly due to young people’s tendency to use their hand-held devices for a wide range of purposes — information and entertainment, social media networks, smart home and smart speakers, amongst others.

Chris Weck

There is no doubt that broadcasters have to be present on that platform with both linear and non-linear audio, with social media and the various functions of the internet.

At first glance, 5G broadcasts seem to be a promising solution for the future of broadcasting, and a viable solution to bring radio to the smartphone — one device and one transmission standard on one transmitter network. But who will benefit from this — the user, the mobile network operators, radio broadcasters or the industry as a whole?

Physical laws for radio communication are still valid for 5G as for DAB and all the other broadcasting and telecommunication schemes. From the well-known Shannon limit of 1948 we know that a minimum of energy per bit is necessary in order to provide an error-free transmission over a channel with a certain bandwidth (Eb/N0 = −1.6 dB in AWGN-Channel).

New and very efficient transmission systems like 5G are able to transmit very high data rates in a channel of a certain bandwidth, however, the energy per bit will never fall under the minimum defined by the Shannon law. With other words, the higher the data rate of a transmission system, the higher the signal-to-noise ratio required. This means in practice for a certain transmitting power the size of the transmitter cell will be reduced for higher data rates accordingly.

Now, from a theoretical point of view with respect to the energy per transmitted useful bit (including all the overhead), there is no significant difference in performance between 5G modulation schemes compared to the still very robust system of DAB+.

The 5G broadcast mode provides also a robust QPSK modulation to make use of bigger cell sizes. However, the expected performance compared to DAB especially in a single frequency network is rather the same. In fact, there are no results of a system comparison in the field available and therefore it is reasonable to focus on other basic differences between the idea of 5G broadcast and conventional DAB+ broadcasting.

Today, DAB radio receivers have an external antenna as well as car receivers. In comparison to a smartphone with a less sensitive built-in antenna, the link budget for the required field strength differs at minimum of 15 dB or even 20 dB and more.

This means that in order to achieve the same coverage for radio reception by smartphones, 10 dB more transmitting power is required. This is also true for 5G broadcast networks, so that 5G broadcast networks for smartphone reception have to aim for 10 dB more transmitting power compared to a conventional DAB+ network. In practice, this means that a significantly denser transmitter network is required for 5G broadcast to smartphones than for conventional DAB+.

Radio reception differs for smartphones compared to conventional radio receivers.  The field strength required depends on the effective antenna size, and has to be higher for smartphone reception.

The reduction of the transmitter distance can be anticipated easily from the CCIR propagation curves. For example for VHF propagation a loss of field strength of 20 dB corresponds to a reduction of the distance to the transmitter from 30 km to 10 km.

With the basic transmitter distance of about 60 km for DAB+ networks, the average transmitter distance for 5G broadcasting to smartphones has to be around 20 km. In fact this means that the transmitter distance has to be reduced by a factor of three in order to overcome a loss of 20-dB field strength. This means nine times more transmitters in the area are required in order to achieve the same coverage as a conventionally planned DAB+ network. Can radio broadcasters really afford this? In fact round about 10 dB more transmitting power results in 10 dB more money.

For the time being, the national DAB multiplex in Germany comprises of 130 transmitters in a nationwide SFN. Today, coverage stands at around 95% for mobile reception, but in order to reach 99% coverage, the number of transmitters has to be increased to 250 at least and may be around 400 (including small gap fillers) in the long term.

With 5G Broadcast round about 10 times more transmitters will be required which might sum up to 2,500 or even 4,000 transmitters in Germany. The mobile network in Germany comprises already 40,000 transmitters today and everybody experiences that this is rather not enough. Concerning 5G mobile networks, experts anticipate that future high data rate networks will be based on a cell size of less than 1 square kilometre, which would sum-up to around 400,000 transmitters in Germany for nationwide area coverage.

CCIR 370 Propagation Curves

What can we learn from these facts?

1. The DAB+ network with its low number of transmitters is the most efficient network to realize a full area coverage
2. The 5G broadcast networks, the mobile network and future 5G mobile networks require far too much transmitters for a full area coverage that nobody can expect the same area coverage as for DAB radio services

Assume e.g. transmitting costs for a full area DAB network in Germany of about €25 million per year. In order to gain 10 dB more transmitting power for smartphone reception, the network will cost a nationwide broadcaster approximately €250 million per year, as opposed to €25 million a year for conventional DAB. In Germany, no broadcaster is in a position to afford this amount of money — the price for this purpose to reach smartphones with radio is incredible high, and quite frankly, out of reach for any public broadcaster.

If one says that 5G would only be applied in cities as opposed to rural areas, the additional costs would indeed be lower. However, setting aside a budget of €10 million a year for this purpose is also unrealistic for a broadcaster and, should this sum even be available, it would certainly make more sense to spend it on the DAB network, where coverage gaps could be closed, and where broadcasters and consumers could benefit from it.

What’s more, it wouldn’t make sense for a broadcaster to give up nationwide DAB coverage. In order to supply 10% of the area with 5G broadcast to mobile phones for the same amount of money.

So, if broadcasters are far from being able to afford 5G broadcasting, who would pay for this? Mobile network operators will never provide a 5G-radio service for free, and broadcasters will not pay for 5G broadcasting either, so there really is no business model for either.

The one and only solution is that the user pays for the broadcasting service to his smartphone — this could be done by a contract with the broadcaster or with the mobile network operator, something that is already being done today with 3G/4G.

The smartphone user has a mobile contract and pays for the data volume on an individual basis. This enables the mobile network operator to set up very dense mobile networks that have enough power to be received by small smartphones. This works perfectly for radio with LTE and even UMTS, so why wait for 5G broadcasts?

Users already have radio services available on smartphones today, and it works well, so long as the user has enough high-speed volume on his contract.

Today, hybrid radio with DAB+ and Internet via mobile networks or via Wi-Fi at home provides the most suitable solution. Hybrid radio is the perfect fit for all broadcaster and user requirements, as with DAB+ it allows broadcasters the proven and most efficient radio network at an affordable price for area-wide coverage. It allows for free access of the users to radio and information, regardless of whether they live in cities or in rural areas, and whether or not they can afford a high-volume data contract for their mobile phones.

Hybrid DAB radio provides broadcasters with a content distribution platform directly linked to the customers, and independent of the commercially driven infrastructure of mobile network operators. This may be an advantage for emergency warnings, too.

On the other hand, users already have audio streaming and additional non-linear services available on their smartphone via the Internet. So, the only need for radio broadcasters today is to think about attractive hybrid radio services, and an impactful marketing strategy for their brand.

I cannot comprehend why broadcasters and politicians would want to switch a system running with DAB and IP with the more expensive, and in practical terms less efficient system that is 5G. Instead, why not use and extend the existing and approved technology? Hybrid radio is the best approach both economically and in terms of efficiency, and this is unlikely to change in the future.

Diversity between broadcaster networks and mobile phone networks will result in better efficiency and will offer more advantages than disadvantages for broadcasters as well as for users — so proceed with Hybrid DAB and IP. There is no need for 5G for radio broadcast.

[Read: Using Digital Radio to Boost Listening Figures and Revenues]

 

The post Does 5G Make Sense for Radio? appeared first on Radio World.

Six industry professionals have already made their plans to attend the 2020 edition of Radiodays Europe in Lisbon, Portugal, as the conference has announced the first batch of its planned speakers.

Those confirmed to speak at next year’s conference are Cilla Benkö, director general and CEO for Swedish Radio; Cathrine Gyldensted, co-founder and director at the Constructive Journalism Network in the Netherlands; Yagmur Özberkan, journalist and presenter for YLE, Finland; Torben Brandt, Danish radio legend; Ole Hedemann, content developer and head of formats at NRK in Norway; and Susani Mahadura, journalist for YLE, Finland.

Radiodays Europe Lisbon 2020 is going to take place from March 29–31, 2020. For more information or to register for the event, click here.

 

 

The post Radiodays Europe Announces First Group of Speakers appeared first on Radio World.

Over the years I’ve become a student of mic preamp design, building and modifying several along the way and learning a little more each time. Usually, I worked from a kit or published set of plans. Recently, I’ve tried some designs from “scratch,” researching various components, studying earlier designs, and incorporating them into raw schematics, followed by circuit layout, design tweaks and final fabrication.

Since my last two builds were vacuum tube devices, I wanted to do a simple, solid-state design this time. I came across some old preamp ICs in a parts box and almost used them but discovered they had been obsolete for years.

Was there a viable updated replacement? Enter THAT Corp., a relatively small IC manufacturer that specializes in chips for audio applications. THAT makes a few chips that are direct replacements of some popular preamp ICs like the Analog Devices SSM2019 or Texas Instruments INA163. If you’ve ever cracked open a broadcast console, you may have seen one. THAT’s website is a treasure trove of design notes and white papers on mic preamp design, with plenty of ideas to get a project going.

This project uses two ICs from THAT: the 1512 Low-Noise Audio Preamp, and the 1646 Balanced Line Driver. Using design notes from THAT and other sources, including advice from several more experienced DIYers, I was able to come up with a relatively low-cost design that has plenty of gain and good performance numbers for most applications.

The mic preamp can make or break a recording. Aside from the microphone, it’s the first stage in the signal chain before the recorder, and in some cases the only stage. It has to be clean and have ample headroom (unless noise and distortion are your thing), yet have sufficient gain to handle a wide variety of microphones.

Professional microphones have a balanced output, so the preamp will have a balanced input. Normally this is accomplished either with transformer balancing, which is expensive, or by using a standard op-amp as a differential amplifier, usually involving two op-amp stages with their attendant gain feedback loops, etc. The THAT 1512 takes care of this within the chip, providing its own balanced input. All that’s needed is a pretty standard input stage that can provide phantom power. The phantom power is sent to Pins 2 and 3 of the input XLR jack through a matched pair of 6.81K resistors, R1 and R2. These limit the current of the phantom supply.

The phantom power section

In order to preserve common mode noise rejection, any components that are mirrored between positive and negative signal paths must be matched in value as closely as possible. SW1 [switch] allows for turning off phantom power when it is not needed, and LED1 illuminates to show the actual presence of phantom voltage. R9 limits current through the LED to keep it from going “poof!” Capacitor C13 is there to smooth out any ripples from the 48 V supply. Between Pins 2 and 3 of the input jack and ground, ceramic capacitors C1 and C2 shunt any RF noise that might hitch a ride on the mic cable. Bad mic cables make good radio antennas!

Keeping stray static at bay is the job of the diodes.

Obviously, we need to keep 48 VDC out of our audio circuit. In a transformer-based design, the transformer would handle this, as transformers only pass AC. Likewise with capacitors, which are much cheaper and take up less space. This is why inexpensive designs use them. The problem is that inexpensive designs tend to skimp on these coupling capacitors. Years ago, I hot-rodded a mic preamp that originally had 4.7µF tantalum capacitors in the coupling stage. I replaced them with nonpolar electrolytics of a much higher value, and performance was improved.

Here, for C3 and C4, I use the same ones. At 100µF it’s overkill, I’ll freely admit, but the higher value reduces low-frequency phase shift (the LF response here is in the single-digit Hz range). Anything around 22µF or greater will work. Besides, it’s very difficult to match capacitors to such tight tolerances.

The high-pass filter is engaged by a switch — SW2.

Here’s where R5, R6, and R7 come in. They form what THAT calls a “T-bias” circuit, which boosts low-frequency common mode impedance. C14 is another ceramic capacitor across the inputs to clean up any remaining RF noise. By the way, R3 and R4 are there to limit any fault currents that might sneak by the capacitors. Their low value prevents input impedance issues.

Additional protection from stray static charges and other voltage transients is provided by diodes D1 through D4. This is a simplified version of a number of protection circuits I’ve seen. Anything ugly gets shunted to ground.

Now, it’s on to the preamp IC, which does the heavy lifting in terms of gain: up to 60 dB of gain, in fact. While a lot of designs will set the chip at a fixed gain level and introduce level controls somewhere between subsequent stages, ours is a simple mic preamp. It would be a simple matter of just inserting a potentiometer (VR1) across the gain setting pins of the chip, right? Not that easy!

Rapid changes in that resistance can introduce DC offset in the chip, which translates to thumping and popping on the output. This is where C5 comes in; a very large capacitor to kill DC offset. Why so large? Because VR1, R8, and C5 comprise a high-pass filter, so the capacitance has to be large enough to bring the low-frequency response down. In this case, it puts it around 5 Hz at maximum gain, keeping any rolloff well below 20 Hz. VR1 is a reverse-log pot, which provides the correct gain vs. position curve.

Capacitors C7 through C10 filter RF gunk out of the power rails to each chip.

Speaking of high-pass filters, I included one here to roll-off any mic or room rumble. C6 and SW2 provide a HPF, but this one has a twist. (Special thanks to the folks at www.groupdiy.com for this idea.) Because the changing resistance of VR1 naturally changes the characteristics of the HPF, this filter’s rolloff actually increases somewhat at higher gain settings. At first, this may seem undesirable, but think about it — low frequency artifacts are more likely to be a problem at higher gains than at lower gains. At any rate, C6 is small enough to rolloff the low end, but not to the point of sounding thin.

Now on to the output stage, handled by the THAT 1646. It’s one of the simplest I’ve ever seen. One IC and a couple of nonpolar capacitors. Caution must be used if inserting any other stages or components before the 1646, as it is very sensitive with regard to impedance. C11 and C12 are there to address any common-mode DC offset on the outputs. From there, it’s on to the output XLR jack, passing through a simple polarity switch, SW3, to reverse phase if needed.

Finally, capacitors C7 through C10 filter RF gunk out of the power rails to each chip, a very important consideration in any design. Clean audio has to have clean power.

Since this whole thing is built around THAT ICs, I decided to simply call it “THAT Thing.” Tune in next time, and we’ll talk about the power supply, breadboarding the prototype, and putting it all together.

More information about the THAT 1512 and 1646 ICs, as well as design notes and other information can be found at:

• www.thatcorp.com/Design_Notes.shtml
• www.thatcorp.com/datashts/THAT_1510-1512_Datasheet.pdf
• www.thatcorp.com/datashts/THAT_1606-1646_Datasheet.pdf

Curt Yengst, CSRE, is a contributor to Radio World and an assistant engineer with WAWZ(FM) in Zarephath, N.J.

Email us with your own DIY ideas at radioworld@futurenet.com.

The post “THAT Thing” — A Solid-State Mic Preamp Project appeared first on Radio World.

First I’ll tell what you already know. Back in the day, AM broadcasting was king and FM was commercial-free. Things changed in the 1970s as FM grew in popularity. Here we are 40+ years later with many AMs struggling. Some have gone away because they were no longer financially viable. To make matters worse, AM directional stations are more time-intensive and costly to maintain, especially when compared to FM stations.

On the positive side, I know a number of smaller AM/FM combination and stand-alone AM stations in Minnesota that are doing well. One town has a 1 kW AM with a 100 kW FM. The AM brings in 40% of the sales revenue because it has always been locally programmed with live announcers until 1 p.m., then is live again during afternoon drive.

AM radio isn’t supposed to sound bad. It can be a clean and pleasurable listening experience, even when there is only 3 kHz of audio bandwidth. On the other hand, AM can be ugly to the ear when there are maladjustments.

SCIENCE

Modulation is the process of adding audio to a transmitted signal. Amplitude modulation is aptly named. A station’s carrier (transmitter power) is varied by the station’s audio. Carrier power is depressed to zero watts to achieve 100% negative modulation. It increases to 1.5 times carrier power when 100% positive modulation is reached. That is why a thermocouple antenna ammeter reading rises with modulation. You read it during a programming pause to get an accurate measurement.

METERING

AM modulation monitors have –100% and +125% lights indicating overmodulation. You really don’t want those lights to come on. More is not better.

First, be sure to set the monitor’s RF carrier level control so the carrier meter needle is in the right spot, as per manufacturer’s instructions. A carrier meter misadjustment will result in inaccurate modulation monitor readings.

Fig. 1 shows an AM modulation monitor. The –100% and +125% lights are on and yet the analog modulation meter reads only 94%. It is normal for an analog meter to read lower than actual modulation. In fact, 85 to 90% is a more realistic meter display, because it cannot track peaks as lights do.

Fig. 1: AM modulation monitor showing overmodulation.

A monitor’s audio output will sound excessively bright or harsh if a de-emphasis audio circuit is not included. Monitors traditionally do not have this, but often a simple capacitor and resistor modification will do the trick. The idea is to undo the high-frequency boost that is a part of the audio processing, per the National Radio Systems Committee (NRSC) standard. As you probably know, the transmitted audio has increased high-frequency response to overcome high-frequency rolloff in most receivers. The goal is to restore flat frequency response to the listener. Some audio processor manufacturers are using non-standard pre-emphasis curves to suit their taste. That complicates getting a realistic feel for frequency response. At least they are trying to make the best of receiver frequency response roll-off.

ON A SCOPE

An article I wrote regarding the operation of oscilloscopes, “Your Scope Is a Tool for all Seasons,” appeared in the Jan. 13, 2013, edition of Radio World.

To refresh your memory, a scope has a display where a dot that travels from left to right is deflected up and down with voltage. In this case, we will look at a transmitter’s RF output.

Fig. 2: An AM RF carrier wave on an oscilloscope.

I’ll begin with Fig. 2. It shows an oscilloscope with a view of the transmitter’s carrier with the scope sweeping at high speed (0.2 microsends per horizontal screen division) to see the actual carrier wave of an AM radio station. By carrier, I mean the transmitter’s power output. What you see is an almost perfect sine wave at the station’s operating frequency.

 

Fig. 3: A carrier with no modulation.

Let’s zoom in to the scope’s screen. Fig. 3 shows the carrier when the oscilloscope is slowed down to view audio (0.2 milliseconds per division). No modulation was present at that instant. Fig. 4 shows a 1 kHz sine wave modulating the carrier 100% positive and negative. The positive parts are the top and bottom peaks. They are mirror images of each other. The negative modulation part is where the carrier is just pinched-off at zero power in the center of the screen. This sine wave is relatively clean/undistorted, with less than 0.5% audio harmonic distortion.

Fig. 4: A carrier modulated 100% with a 1 kHz sine wave.

Many receivers do not reproduce it that way. The last 5 or 10% of negative modulation, between 90 and 100%, is where receiver detectors have trouble faithfully reproducing what the transmitter is sending. The result is audio distortion. We all know that unwanted audio artifacts are a listener turnoff.

Fig. 5: 100% modulation with receiver detector output.

In Fig. 5, I’ve switched the oscilloscope to dual trace mode. It shows the transmitter at 100% modulation on the top trace. The bottom trace was sampled at the receiver’s detector. I made the measurement there so it rules out additional audio harmonic distortion, which might be added in the output stage. By definition, harmonic distortion is where this 1 kHz audio tone will have unwanted audio products at 2 kHz, 3 kHz, 4 kHz etc. because of non-linear system performance. In this case, distortion from transmitter through the receiver detector measured 5.1%. It was only 3.1% at 90% modulation.

Fig. 6: 125% positive modulation, 100% negative modulation with receiver detector.

Fig. 6: Traditional analog audio processing used diodes to clip the negative side of audio before it went to the transmitter so it would not attempt to overmodulate the negative modulation while allowing positive modulation to go to 125%. The downside is that it added as much as 6.5% harmonic distortion in the process. Add the receiver’s problems to the mix and you have a whopping 10.2% distortion. Ouch! You’d never allow that on FM.

Newer digital processors reduce but may not eliminate the problem. Yes, the station can be a bit (about 0.9 dB) louder on the dial, but it is irritating to many listeners. They don’t know how to describe it, but oops, there goes another tune-out! Again, some people hear it and some don’t. Best not to penalize the station with high modulation.

Fig. 7: The transmitter is being badly over-driven at 100% negative modulation.

Fig. 7 shows the transmitter being modulated at over 100% negative modulation. I’ve moved the scope’s trace up a bit so you can see detail. Negative peaks go flat to the center, which is no carrier at that instant. Modulation like this will not pass the required NRSC occupied bandwidth nor will it pass my ear test for listenability. It is tiring to hear.

Fig. 8 is where you want to be. No more than 95% negative modulation, the sweet spot between loudness and listenability.

Fig. 8: 95% program modulation of the carrier.

It is a shame to lose listeners for that last 5% (about 0.5 dB) of modulation. Few if any will hear the loudness difference. Likely most will hear grit in the audio of transmitters modulated to the max. You can make up much of the modulation percentage difference with careful adjustments of the audio processing, before it goes to the transmitter. Software-defined receivers eventually will solve much of this problem, but we need to deal with today’s radios.

When I was installing AM stereo years ago, negative modulation was usually set at 95% and positive modulation at 95% for stations to sound clean. It was positive +125% if the client preferred it. That extra positive modulation comes as “forced asymmetry” where the negative audio peaks are soft clipped so the positive peaks can go higher. Ouch!

Surprisingly, bad-sounding audio with less than 100% modulation will usually fit into the NRSC occupied bandwidth mask, in the FCC required annual measurement. That is because of the required 9.5 kHz low-pass filter in audio processing.

AM stations competed in loudness wars to beat the other guy years ago. Now it is time to give listeners a pleasant experience with natural-sounding audio. Don’t drive them away.

I grew up in a broadcasting family that owned two AM stations and no FM. Success was dependent on keeping listeners. Loudness was not the answer.

Comment on this or any article. Write to radioworld@futurenet.com.

Mark Persons, WØMH, is an SBE Certified Professional Broadcast Engineer. He recently retired after more than 40 years in business. His website is www.mwpersons.com.

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