Radio Waves: Stories Making Waves in the World of Radio
Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!
Many thanks to SWLing Post contributors Pete and Dennis Dura for the following tips:
Now Is the Time to Save AM in Cars Using Digital (Radio World)
“DRM eliminates unstable and degraded audio, saves spectrum and, more importantly, a lot of energy costs”
The author is chairman of the DRM Consortium. Her commentaries appear regularly at radioworld.com.
Much ink has been used recently on the topic of carmakers dropping AM reception capability in cars, especially in EVs. Hence the “for and against” discussions in the U.S., at least, about the “AM for Every Vehicle Act.”
Shortwave reception, with is large coverage possibilities, has often been criticized for its audio quality which can be noisy and subject to annoying levels of variations. In cars, there are other drawbacks like less than optimum antennas, which are mostly tuned for vertical polarization while shortwave is horizontally polarized.
It is undeniable that analog AM Shortwave reception in cars can be quite unreliable, also due to lower average-SNR over time. But all these negative points are not always present. In some places (take Nigeria and the BBC broadcasts) the shortwave transmissions are great, in a quality that is not much different from that of a FM broadcast. [Continue reading…]
Bong! Big Ben broadcasts to return to Radio 4’s regular schedule (The Guardian)
Westminster’s famous bell will be heard live from next week after years of only occasional appearances
It is one of the most recognisable sounds in the UK, and one that hasn’t been heard on BBC Radio 4 since New Year’s Eve last year, but from next week the famous bongs of Big Ben will be heard once again on the station.
The most famous bell in the UK will be heard live once again on Monday 6 November, just before the 6pm news bulletin and again before midnight. Listeners will be able to hear the chimes again before Radio 4’s Westminster Hour political discussion programme at 10pm on Sundays.
And after years of only occasional appearances, the chimes will form part of Radio 4’s regular schedule where they will be heard live twice daily and three times on Sundays after new microphones and a live set-up were installed.
To mark the nation’s two-minute silence this Remembrance Sunday, Big Ben will also be heard live on 11 November at 11am, and the bongs will air at 3pm on Christmas Day, before the king’s speech is broadcast on Radio 4. [Continue reading…]
RNZ Pacific’s shortwave service turns 75 (Radio New Zealand)
It has been 75 years since Radio New Zealand started broadcasting on short-wave into the Pacific region.
Using two 7.5 kilowatt transmitters in Titahi Bay, near Wellington, Radio New Zealand began short-wave broadcasts to Australia and the Pacific in 1948.
RNZ Pacific’s Moera Tuilaepa-Taylor has this report.
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Hi there.
Glad to know that the chimes are back on Radio 4.
Miss chimes and Lilliburlero in World Service, wish a comeback!
And my congratulations on the 75th anniversary of RNZ HF Broadcasts.
A lighthouse in the Pacific. (Able to listen from Argentina almost daily).
Promoting DRM as an alternative to anything is a sign of delusion. Obviously, I get why the chairman of DRM consortium is doing this, but the general public should be aware that DRM is a technology that has been around since 2 decades, not some new breakthrough development. These 2 decades showed that no one considers DRM as viable. The broadcasters who used to run trials (which were pretty common around 2005-2010 – there actually was something to listen to in DRM at that time) have either reverted to AM or ceased transmissions altogether, nowadays there is only a handful remaining. Electronic manufacturers also didn’t jump the ship. No DRM receiver can be found today on ebay, amazon, etc. Not a single one. Trying to go digital by resurrecting a 2-decades old failed technology, misleadingly calling it a possibility to “save AM” makes the same sense as convincing people that it is a great idea to ditch smartphones and replace them with early 00s cellphones just because their batteries lasted longer (similarly to the “DRM uses less energy” argument). Not going to happen, it’s not possible to step in the same river twice.
Please get up todate.
There are 38 high power up to 1 Megawatt transmitters in India. The highest AM in the USA is only 50 kW. The car manufacturers are installing DRM receivers in virtually all new cars for no extra cost. They have done 6 million cars already and it is rapidly increasing as the number of cars manufactured increases.
Also there is now a module which goes from antenna to speaker for $US10 for manufacturers and Gospell has them in two of their two models. The power consumption is less than analog radios. There are none of these receivers on ebay, amazon etc because they are aimed mainly at the North American market where there are not only no DRM transmissions internally or aimed at that continent because domestic high frequency broadcasting is banned. You have the HDRadio system. The other digital system which is selling well is DAB+ in Europe and Australia. The Europeans in 2020 made terrestrial digital receivers compulsory in new vehicles.
I remember the opposition to the conversion of TV from Never Twice the Same Colour analog TV to the ATSC1.0 digital TV in the USA. It was pushed by the telcos to get the 700 – 800 MHz band. No one wants to go back to analog TV. Why shouldn’t radio go digital just like the telephones.
Just remember that in the USA what you call AM is a method of modulation not the frequency of transmission. Just as DRM is a method of modulation as well as digital encoding. Both AM and DRM will work at the medium and high frequency bands. AM is not used at VHF because of its poor noise performance where as DRM is used there and in competition with FM.
Anyone who has listened to DRM from 4000 km away with crystal clear sound from the high frequency band (SW) will realise how good this technology is. In addition
I think I am sufficiently up-to-date, I have also tried receiving some of the DRM broadcasts that were available in Europe, and my findings were completely different, I was shocked by how much the transmission was prone to drop-outs and how much the sound quality was degraded by lossy compression – to levels comparable only to early 90-s mp3 files.
I saw some examples from India where they apparently thought it was a good idea to put 2 different stations on a single DRM MW transmitter, effectively giving each of them around 10kbps of audio bitrate. This would have been ridiculously and comically low value if they didn’t spend public money on that. My dialup modem could do around 40kbps in the 90s, now I have fiber, 5G mobile connectivity while DRM remains in the same place as 2 decades ago. It’s clearly visible. Therefore, I get why DRM may have been interesting in the early 00s, when it was developed, but since then, it had simply stagnated and the world has moved on.
As for the receivers, this argument emphasizing the issue of different markets doesn’t really hold up. DRM is promoted as a worldwide standard – hence Mondiale in thename. A quote from the DRM consortium website: “this is a unique open standard covering all bands, offering a solution for anywhere in the world”. It clearly isn’t a solution “for anywhere in the world”. Even though I live in Europe, where there are still some DRM transmitters operating in selected parts of the day, I cannot buy any DRM receiver from any shop operating online. It’s a pure flop. The module may cost $10, may as well cost $20 or $0.01, but it doesn’t matter at this point, since apparently no electronics manufacturer decided to offer products containing that module. If you claim I’m not “up-to-date”, please provide a link, name, or any hint on a shop which offers a DRM receiver to retail consumers anywhere in the world.
https://www.aliexpress.com/w/wholesale-Gospell-DRM.html
Many thanks for providing the link, but I think you can agree that the pricing is absolutely ridiculous. The DRM module was supposed to be $10 and now they ask $300+ for a single receiver? Is it made of gold???
Again, I am really not a fan of internet-based radio by any mean, but it’s not possible not to see that for the same price I could get a new 5G-enabled smartphone, meaning cutting-edge technology both in terms of radio modem and processing power, while this Gospell company is asking for literally the same amount of money in exchange for a single-purpose device employing a 20-year-old technology. I don’t really think this has a business potential.
Dave Mason,
The move from analog to digital television was because the telcos wanted the 700 – 800 MHz band for call phones particularly wireless broadband. This was not possible without the conversion of analog to digital TV . In analog TV there must be a disused channel between a pair of active channels in a coverage area. With digital TV consecutive channels can be fully occupied with signals, even from the same antenna.
The move from analog to digital TV has also meant the desertion of any transmission below 174 MHz. This is because the lower frequencies mean larger less directive antennas (allowing in more ghosts from reflected signals and more impulse interference. This means that nearly all of the frequencies between 47 – 88 MHz are now empty and suitable for DRM in channels 0.1 MHz wide. The impulse interference is less of a problem than it is in wideband TV and is much less than for DRM in the 530 – 1700 MF band.
Radio just needs to follow the TV changeover example. Ban the import and manufacture of non DRM receivers and have a rollout plan for transmitters and for distribution to retailers and a selling campaign on the media.
Mangosman
Hate to tell you this, but at least here in US this was all about Hollyweird wanting to force the OTHER DRM:Digital Rights Management AKA banning recording of OTA. There was backlash on the first ATSC so it wasn’t implemented but now it’s being forced with ATSC-3 along with an RF return channel so they can spy on you even without a connection! You’ll notice on most consumer-facing sites this RF return (up to 10W TX power!) this is deliberately never mentioned, but on industry-facing sites like Radio World it comes up on occasion.
YES, moving from analog to digital saves a ton of bandwidth and also gets you digital (aka processing) gain so a tenth of the power is required if they do things right. ATSC-3 also finally goes with the same OFDM that DVB uses but is still protocol-incompatible. 🙁
As for ghosts and impulse interference NTSC and ATSC-1’s VSB might care about that, but OFDM does not. In particular, these digital transmissions can use active beamforming just like cellular and access points, provided you have the antenna for it. A significant amount of processing goes towards dealing with echoes (ghosts) and recovering info from them, just like on your phone.
However, there’s no getting around that LARGE antennas are needed on the low VHF band channels. No one wants to do that anymore. On the flip side, cellular companies are desperate for the high UHF TV channels as their low band, thus T-Mobile USA’s Band 71 in the 600 MHz region because they are penetrating over their microwave counterparts (much less mm-Wave). Even more in parts of northern Europe where 430 MHz or so is still authorized for some cell phones, though that info may be outdated.
Finally, I have to disagree yet again on “saving” AM (MW) here in NAm: its only still used for local because the people in the media side of the regulatory agencies are stupid and station owners don’t want to lose their equipment investment. In reality, we should be running MW like elsewhere in the world with a few high power regional transmitters utilizing skywave properly like SW at night instead of the mess it has been my whole life. As for FM / DRM / HDRadio, the low VHF band should be used for this–as it is, most tuners support down to 64 MHz with just a firmware update as used in Asia–but the agencies don’t seem interested.
Oh yeah and having been though the forced change I don’t want to do that again. Forcing people to do things no matter what is the evil HOA way!
Hope this helps!
Mike,
Digital Rights Management is a computer industry standard to prevent the copying of computer programs. As far as TV is concerned the blockage of copying occurs in the HDMI interface which knows whether the destination device is a display device or a recording device. TVs do not have analog video outputs and video recorders at the time were totally analog.
The return channel cannot apply to any broadcast system because it is one way. They can transmit an internet address to the receiver and hope that the viewer will connect the TV to the internet to return any requested data. This is from each receiver. I don’t know where you get the 10 W come from. ATSC1.0 is one serial data scream which would have to have to a slot of time to transmit the IP address and any commands.
COFDM used in DVB transmits the data in bursts to allow reflections to be ignored, however signal strength is increased if you use a directional antenna in fringe areas.
The problem with ATSC1.0 is a suppressed carrier AM system with some of the lower sideband removed.
Is US pride so great they could not use DVB-T(2) which is used everywhere else except Japan, parts of South America, Sth Korea and the Philippines?
ATSC3.0 is a modified version of DVB-T2 along with DVB-T. They both use which has been broadcasting for up to 23 years. Australia did a side by side comparison between ASTC and DVB-T which is why ATSC is only used in North America and South Korea.
TV transmitters have been using either omnidirectional or directional antennas since it started. Directional receiving antennas hare common except for indoor antennas common in the USA.
DTV antennas are much smaller when you leave out any frequency below 174 MHz which in the USA is channels 2 – 6 which are now virtually vacant. Look at the current FCC station list.
AM particularly is very wasteful of electricity because between 67 – 100 % of the radiated power is the carrier which carries no audio. DRM can transmit 18 programs on a single FM transmitter at much lower power also saving lots of electricity..
If the telcos can convince the TV industry to replace much more expensive transmitter than radio, radio should do it to save money and improve sound quality and be able to transmit emergency announcements, maps, detailed instructions and the location of road blocks which AM and FM cannot.
Lastly the telcos are not interested in the VHF band because the antenna does not fit in the phone.
There’s a lot of talk about “changing” and “saving” AM radio and much of it involves extra expense on the part of the consumer. TVs transition to digital was mandated, and facilitated by cable and satellite companies providing signals to older, analog TVs. If “AM” needs a fix, an additional spectrum should be created, those AM stations allowed to simulcast for an extended period and then announcing a “shutdown” date for the old AM band. One thing to consider is the long-range reception capabilities of AM. Yeah, the internet allows us to hear radio from all over the world-but in an internet outage-then what ? You’ve also got to consider what is ON AM vs. what would be on the new digital platform? If it’s the same old stuff we hear now, in most cases, you’ll find consumers won’t drop a penny on new tech that doesn’t provide a huge benefit.
I’m glad to see a positive “Let’s all go digital on medium wave NOW!” article after the recent run of lets-ditch-AM op-eds. And I agree, it is time to move on to an open digital standard for the “AM” band.
BTW, we’re going to have to stop calling it AM if we do this. Following the UHF, VHF, HF, convention, can we just call it MF and get Samual L. Jackson to do promotional ads for the new standard already? It may not ready for prime time, but at least it would be memorable.
North Amerika should go for….DRM..! Why such a mystery and procrastination..?
One big problem with DRM here in the U.S. is the name, which is almost universally read as “Digital Rights Management,” i.e., encryption and/or copy protection of music files. Say that in conjunction with “radio” and it immediately conjures in tech peoples’ minds some kind of payment scheme for receiving broadcasts. As the saying goes, “you don’t get a second chance on first impressions,” and just using the letters DRM shuts the door.
Which is a real shame, because the recordings of tests I’ve heard sound very promising.
Three cheers for RNZ Pacific! And indeed for Moera and Adrian, who were both lovely colleagues when I had the privilege of doing a few shifts at the then RNZI. Probably a low-point in the 75 years 😉
Happy Birthday RNZ Pacific!
Congratulations to Radio New Zealand High Frequency broadcasts. They are currently building a new 100 kW DRM capable HF transmitter but we are yet to hear of an on air date. https://ampegon.com/wp-content/uploads/2020/03/Leaflet_100kW_Shortwave_Transmitter_TSW2100s.pdf
For progress see the bottom of the home page http://www.drmna.info/