Posts Categorised: Tips and Tricks
Just how cheaply can you operate a radio station?
Quentin Howard is a man with a mission: To work out if he can run a fully-featured radio station on hardware that costs less than $99.
Quentin, who was chief engineer for the UK’s national Classic FM and instrumental in the UK’s adoption of DAB Digital Radio, is running his own radio station as a bit of fun — deliberately using cheap hardware.
“I wanted to run a fully-functional radio station — with a completely automated music schedule, station IDs, encoding and streaming, and pulling in external audio sources. I wanted it broadcasting the time signal at the top of the hour; and for me to be able to broadcast live if I wanted to,” he said.
The system that does this? A £70 (US$94) tablet computer, running Windows 10. The challenge that Quentin has set himself is to ensure that the system runs reliably, and the touch software remains responsive and usable on a 7-inch screen.
Keen to experiment, Quentin is testing this using a classical music format.
“Classical titles are more complicated to music schedule — extreme durations, multiple artists, composers, different versions of same piece, segues in different keys, screeching sopranos, non-English alphabets — so it’s a good stress test of music rotation and playout, which is really what this is all about. If it can do all this well, any pop/rock format station is a doddle!”, he says.
“Announcer breaks are done on my mobile phone, uploaded to Dropbox from anywhere and played out a few minutes later which is, in effect, a one man live-assist OB.”
Playout is handled by PlayIt , a low-cost suite of radio software produced in Cambridge, England.
“I’ve watched this product evolve over the last few years and I’m still impressed. It’s very stable and resource light. Standard playout software is free (non professional use), voice tracking and more sophisticated networked systems cost literally a few pounds. There’s lots of low cost playout systems of course — I’ve tested over 60! — but I rate this one highly.”
The station, which Quentin has christened “Radio Birdsong,” is streaming live on the internet. “You could hook this up to a £28 (US$37) FM transmitter, and have a fully-functional radio station for less than $140 — no larger than a hardback book,” he adds.
Elsewhere, low-cost radio solutions are already on the air. Ash Elford, manager of the small-scale Portsmouth DAB multiplex in the south of England used a small SD card player — costing less than $5 — to air one simple radio station for three months. The service, Sleepyhead Radio, was a set of looping programs for babies and their parents. The SD card player was purchased on eBay; the micro SD card was “just lying around,” he told me.
Ash also ran a set of automated radio stations called Weather 24/7, which broadcasts the weather forecast on DAB multiplexes in parts of the UK, using reconditioned laptops.
At the other side of the world in Australia, radio technologist Anthony Eden has recently compiled a collection of over 20 pieces of free broadcast software .
From studio clocks, to silence detectors, DAB encoders or playout systems, there are a lot of freely-available pieces of software to assist radio stations. Anthony’s list includes many open-source projects, which enable individual radio stations to add more features to the software or integrate it into existing services.
Meanwhile, Quentin Howard continues to experiment with his service: taking his entire radio station mobile. “I used a Bluetooth data connection to a mobile phone, and was able to stream the station uninterrupted from a moving vehicle,” he said.
“One application I’m developing it for is disaster emergency broadcasting. Pre-programmed FM radio in a tiny box, ready to go and cheap enough to throw away.”
“You could do all this on an Intel core i7,” he adds. “But where would be the fun in that?”
James Cridland reports on international radio trends from Brisbane QLD, Australia.
As digital footprints grow and cyber infrastructures mature, more industries are exploring potential uses for blockchain
From using an app to order your morning latte to reading an eBook before bed, we’re living more of our days — and our lives — online. As digital footprints grow and cyber infrastructures mature, more industries are exploring potential uses for blockchain. Blockchain is shared ledger technology for recording transactions and protecting the integrity of digital information.
HOW DOES IT WORK?
Imagine having a ledger book and inputting all relevant data about a purchase. Instead of sliding that ledger onto your bookshelf, you make it public and give a tiny piece of it to hundreds of others. The ledger can be seen as a data, but it is secure due to its advanced encryption. Blockchain is that distributed ledger, and it is not housed on one server. No one person or one server contains it. It is fundamentally decentralized.
Let’s say you want to buy a new track from your favorite band. You’d buy the digital file online using your Visa card. Visa would store that transaction, and the place you are purchasing the music from would store it. It would then be housed in two locations. On a blockchain, the transactional information doesn’t live in only two locations, it lives in hundreds, thousands, or even millions of places — living on the peer-to-peer computers running the blockchain encryption. A blockchain system replaces human guesswork and vulnerability of digital transactions with algorithms and advanced cryptography. It’s harder to hack. It’s a whole new way of thinking and a brand new method for securing digital information.
To recap: Blockchain creates a permanent record of digital transactions; it stays secure because the data is verified and encrypted. Blockchain operates on a decentralized peer-to-peer network, and its model is scalable. The blockchain’s digital ledger can be viewed and distributed, but it cannot be altered.
SECURE AND TRACEABLE
In a time when even SSL-protected environments are breached, blockchain’s transparent, decentralized approach to cybersecurity is increasingly attractive, according to Mike Walker, research director at global intelligence firm Gartner Research. Walker views blockchain as a “potentially transformative digital platform.”
Walker, also an author of Gartner’s Hype Cycle for Emerging Technologies 2017, explained that blockchain’s traceability is another element of its growing appeal. “The Honduras government will use blockchain to secure land titles,” he said. Other use cases for the digital ledger include blockchain-enabled voting machines, online music payments, asset transfer, and cloud storage. Samsung SDS blockchain technology will work to bring more transparency to the city of Seoul. From to charity giving to insurance markets, any industry using all-digital assets is poised for disruption by blockchain.
WHO’S ON BOARD?
The technology was created to support the cryptocurrency Bitcoin, and its peer-to-peer model is best suited for similarly digital-only ecosystems.
“First-order applications for blockchain are purely digital,” explained professor Christian Catalini, founder of the MIT Cryptoeconomics Lab at the MIT Sloan School of Management. The reason we see it at scale in the financial sector, supporting online banking and accounting, is because “blockchain is good at digital verification,” he said.
WILL ALL INDUSTRIES BENEFIT?
Beyond the financial sector, blockchain is a candidate for any application that relies on digital value transactions. New sectors embracing blockchain are supply chain management and logistics, “file storage, data storage, bandwidth, and even electricity grids,” according to Catalini. “File storage online is easy to meter and measure,” he explained, and therefore an appropriate application for blockchain.
Gartner Research suggests that the “blockchain revolution promises to touch every industry,” but the realities are nuanced. While we see this technology being embraced to support auditable voting, currency, software, and digital data transactions, the all-digital nature of these ecosystems is why blockchain is both feasible, scalable, and makes economic sense. Where there is mix of physical data and digital data, however, requiring users to port information stored offline into an online system, blockchain’s adoption will take more time. Sectors such as education and healthcare are increasingly interested in blockchain — deploying pilots and experiments — but the evolution will be slower.
Established heavyweights and startups alike are exploring ways to leverage this technology to solve problems. Dell EMC Global CTO John Roese said that blockchain has “forced us to rethink how we deal with sharing technology and how we develop database architectures.” Google, IBM, Cisco, Bosch, and Oracle are a few notable examples of companies who have joined blockchain alliances, pilot programs, or are pursuing proprietary solutions of their own.
ONE CHAIN TO RULE THEM ALL?
Blockchain is available in open-source platforms and it offers quantifiable benefits for all-digital environments, but don’t mistake it for the panacea, warned a 2017 report from Tractica, a market intelligence firm that focuses on human interaction with technology. In that same report, Tractica analysts urged businesses to “avoid jumping on the blockchain bandwagon and instead view blockchain as a series of technological modules and concepts to selectively choose, apply, and/or complement other emerging technology trends.”
Blockchain also has limits beyond the digital-only prerequisite. A diversity of nodes will help defend against the so-called “51 percent” attacks that could compromise blockchain-supported data. A “51 percent attack,” according to Coindesk author Frederick Reese, “would find a single entity introducing a version of the blockchain that it controls and is accepted as valid.” But on one small college campus or in one building, is the required physical diversity of blockchain peers possible? What makes it an ideal platform to scale may also limit it for smaller use cases.
While blockchain is already disrupting the financial sector, perhaps its greatest promise is how it radically reimagines a digital information infrastructure. With its decentralized, broadly distributed model, the immutability of its transactions, and vetting of online identities, blockchain builds trust into the very architecture of its system.
Blockchain may not be the right fit for every industry, nor is it an immediate answer to the question of how to safeguard digital information, but its paradigm shift is already inspiring next-level innovation.
SOURCES AND MORE INFO
Catalini, Christian and Gans, Joshua S., “Some Simple Economics of the Blockchain ” (September 21, 2017). Rotman School of Management Working Paper No. 2874598; MIT Sloan Research Paper No. 5191-16. Available at SSRN.
NEED TO KNOW MORE?
Have a burning question about blockchain — or maybe request for a different topic you’d like to see us tackle? Email us at email@example.com, and we’ll put our top minds on it!
Without the proper attention, uninterruptible power supplies can create more problems than they solve
LOS ANGELES — Uninterruptible power supplies are a necessary evil at transmitter sites and rack rooms. Without the proper attention, UPSs can create more problems than they solve. Let’s take a look at some ways to minimize those potential problems.
SINGLE POINTS OF FAILURE
A single point of failure is generally one piece of equipment, the failure of which “kills” the radio station. Often, single points of failure are found in inherited systems, but sometimes you will inadvertently create one when installing new gear without a clear plan. UPSs easily fall in to this category because they often just get racked up in order to “protect” a new piece of gear that is particularly susceptible to power hits. They are added to a rack, plugged into raw AC power, and then the new gear gets plugged into the back of the UPS, and we’re on our way back to the studio or home. Later, more equipment gets plugged in, and then something else, and on and on.
Of course, the nightmare scenario is that the main and backup systems get plugged into the same UPS, and then it conks out on you — not because of the load, but because of a component failure, or more likely, battery failure. Say you plugged in two STLs or two audio processors to the UPS. It fails, and then you’re left with nothing but dead-air until you get there to move the AC power cords around.
STRATEGIZE AC POWER SOURCES
One way to get around that scenario is by using multiple UPSs and being certain that all critical gear is plugged into different units. Consider these steps:
- Have one UPS per rack. If you have multiple racks, consider having a UPS at the bottom of each rack. Also make sure that each UPS is fed from a separate AC circuit breaker. You wouldn’t want a single breaker trip or a failure to kill power to more than one rack, right?
- Don’t connect main and backup systems to the same UPS. Engineers organize stuff in racks in different ways. I like to separate main and backup systems into different racks, which is why I place one UPS per rack. It’s easier to organize power feeds in this fashion.
- Main and backups in the same rack call for clearly labelled power strips. If you have only one rack, or you have mains and backups in the same rack already, then install a specific AC outlet strip fed by a separate UPS and plug backups into that, instead.
- Keep mains on UPS. Keep backups on raw power. If you simply don’t have room for two UPSs, then keep backups plugged into raw power instead. Make sure your remote control, used for the switching, isn’t plugged into the UPS.
TWO TYPES OF UPSs
You likely know there are two types of UPSs: those that only switch over to battery power when there is a power failure, and those that are online all of the time. I prefer the latter because I find that the former allow surges and brownouts to pass right through (depending on the length of the event, of course).
Online UPSs use double-conversion, meaning they take the AC power, rectify it, charge the batteries, and then use the DC to generate a sine-wave output. There’s no switchover time because the batteries are effectively the DC source for the 60 Hz oscillator.
One advantage to the off-line type is that the batteries can be easier to swap out. Keep that in mind. An example of the online type would be those made by Falcon electric, and a typical off-line brand would be APC.
Remember to label new UPSs with information about when they were new or when new batteries were installed. It’s a good idea to note this information in your maintenance records, too. My rule of thumb is replace batteries in off-line UPSs after three years.
Every radio station should have, at minimum, two ways to get program audio to the transmitter site
LOS ANGELES — An STL system is just as crucial in a radio station’s air-chain as the transmitter or antenna. After all, if there’s no audio to transmit, then even the best transmitters and antennas are of little use. No one tunes in to hear dead air.
Every radio station should have, at minimum, two ways to get program audio to the transmitter site. A radio STL at 950 MHz is a good option for one of the two means. “Wireline” of some sort is a good choice as well. (By wireline, I mean any type of connectivity provided by the local exchange carrier—whether audio circuits, T1s, or metro Ethernet.) Technology diversity is the best way build redundancy in to your STL system. Your primary and auxiliary STLs should not both be of the same type; if you use “wireline” for the main, use radio for the aux, and vice-versa.
Let’s take a look at the reasons for this assertion of mine.
PROBLEMS WITH RADIO LINKS
While private radio links make great STLs they are subject to problems, including these:
- Outright equipment failure
- Antenna/transmission line failure
- Interference that just shows up one day
- Deep fades
Let’s talk about the mitigation of these issues one at a time.
Equipment failure. This is the most likely means by which you will “lose” your STL. Clearly the best way to get around this is to have a standby transmitter, and a standby receiver, both of which can be switched ON using remote access. The receiver part is easy—derive two separate antenna feeds, drive the input of both receivers, and then put a switch on the outputs so that either can feed your air-chain. The transmit side is a bit more difficult—since they both can’t be radiating at the same time. The most practical approach is to use an RF switch to select the output of one of the two transmitters to drive the transmit antenna. Another (better) approach is to have separate transmit antennas. No RF switch is necessary then, but you’ll still need a way to turn one transmitter ON and have the other OFF, and the ability to reverse their roles.
[Related — “Best Practices: Value Engineering “]
Antenna and/or transmission line failures. Another way radio STLs fail is by way of bad connections on transmission lines and antennas. Often they sit out in the weather for years, and if they were not installed correctly to begin with, problems can show up several years down the road.
If you have two receivers, ideally they can be fed by separate antennas; that way, a failure in the receive antenna system won’t leave you with two non-working receivers. Separate feeds are best, even if one is from an inferior antenna.
Likewise, on the transmit side, having a choice of antennas provides an advantage. Even if you have two transmitters, having a bad transmit antenna will leave you with little prospects. This type of problem often shows up at the worst time as well—say for example in the winter—so getting someone out to fix it might not be as easy.
New interference. 950 MHz-band resources are typically shared amongst multiple users in a market. The unfortunate reality is that a radio system that is working fine one day can sometimes be interfered with the next, leaving you scratching your head. New systems come up (though you should know about any of them through the Prior Coordination Notification protocols) and create problems unexpectedly; a random transmitter in the field might develop spurious emissions that accidentally show up on your channel; and there’s always the possibility of newly developed intermodulation products at the receive site. If you are using a digital system, there’s also the possibility of desensitization of your receiver, because of strong, local carriers that are nowhere near your own frequency.
These types of problems are rarely solved in a day and the best way to be prepared is by having one or two other means by which program gets to the transmitter site.
[Related — “Best Practices: Krone Blocks “]
Deep fades. If a path is poorly designed, or if it has other problems, none of which had come to your attention previously, you might experience signal fades on the path that are deep enough to make your receiver “mute” causing dead air. When you first start at a station you should take note of RSSI levels on the receiver(s) and also forward and reflected power readings on the transmitter(s). Sometimes transmission line problems can make the signal weak at the far end (though still receivable) while not knocking it all the way out (i.e., fade margin is unexpectedly used up). Antennas that are not aligned properly can cause similar problems.
Radio plus wireline strategy. So, to reiterate my earlier assertion, technology diversity is the best way build redundancy in to your STL system. There’s simple logic behind this idea.
While there are four primary ways to have a radio system knocked out (see above) none of them is related to the performance of “wireline.” If you experience any of the four you can switch over the wireline and keep going while you figure out your radio problems.
Conversely, wireline problems, when they happen, will be totally unrelated to any 950 MHz system performance. Wireline issues would include fiber cuts, power outages, and other miscellaneous central office equipment failures.
One exception I will point out is the use of part 101 radio systems. It would be acceptable to use 950 MHz and 11 GHz radio systems as main and auxiliaries.
Doug Irwin has yet to work on a project for a radio station in which money was not an object — and the same is probably true for you
This isn’t so much about technology as it is about techniques
“SPOF” refers to a single point of failure and can be applied to almost system
More advanced receivers will sometimes change stations at “random” while the vehicle is in motion, if the same PI code is used by multiple stations