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What You Think

User Opinion Story
Anthony The Koala
16 August 2019 - 9:57pm
Dear StJohn,
Thank you for your reply.

You have confirmed what I said about using lossy compression files in the transmission/reception chain sounding poor.

Thank you for elucidating on the number of 'services' on one DRM channel being three. If two DRM channels can fit onto one FM frequency, given one FM frequency occupies 200kHz, then one DRM channel is 100kHz. It follows that in the AM band typically 1602 to 522 khz has a bandwidth of 1122kHz can fit approximately 10 DRM services. On the FM channels, 108MHz-88MHz = 20Mhz, which gives approximately 20/0.1 = 200 theoretical DRM transmitters. With 3 services per DRM transmitters, that's the equivalent to 600 DRM services. Theoretical because that does not take account of any co-channel interference whether it's on MW or VHF.

HOWEVER, I do note that with DRM and DAB+ transmissions, the same frequency can be used in different areas PROVIDED that all DRM and DAB+ are synchronized using accurate clocks. Synchronization shouldn't be hard because atomic clocks have been used in broadcasting for decades.

My calculations were based on the third paragraph of three programs on one transmitter, NOT the fifth paragraph, where you say that one can fit 6 DRM channels on one FM channel. Please clarify the 3 channels and 6 channels distinction.

Nevertheless, that does not account what for what is final government policy on spectral allocation of DRM services.

One question I would like to ask you is when the DRM signal is on MW or SW bands and due to the properties of the ionosphere such that MW and SW signals skipping long distances is: what is the quality of the received signal over long distances? In addition is there enough error correction information sent with the DRM signal that the recovered signal at the receiver is 'perfect'?

I noted in your previous answers (plural) that DRM has the facility to transmit pictures and text. The questions about pictures and text services raises non-engineering questions but economic: will the radio stations be able to afford providing pictures and text services OR will the radio stations want to monetise and and let other parties pay to use the text and pictures services. A corollary to auxiliary text services is the teletext service, text services on analogue tv as well as DVB. Teletext services providing news, weather, market information was abandoned by the Seven network nearly 20 years ago. The justification for the abandoning of teletext services was that such information was available on the web! Similarly the potential of DRM to provide text and picture services, one asks will it be utilized when the information is available on the web, especially the radio station's web page.

REGARDLESS of technology: whether DRM or DAB+ or web pages, it is an issue for the broadcaster to keep information up-to-date. For example, a former 2UE personality who left 2UE nearly three years ago is still publicised on a rural radio station's web page http://www.hayfm.org/wp/show/stuart-bocking/ . Nevertheless, I do note that DRM's capability to send pictures and text - regardless of DRM or WEB technology, the information needs to be up-to-date.

I must disagree with you about the alleged 'exaggeration' of the use of the FM band. My description of the FM band is EXACT. Yes I am aware for example that VHF FM bands are not the same world wide. For example Japan's VHF FM band is between 75MHz and 95MHz. I was talking about the 88MHz to 108MHz band as used in the Australian market place. All my 88MHz to 108MHz FM receivers can receive frequencies beyond this band. There are services used below 88MHz for example in Sydney for multicultural languages such as Campbelltown's Spanish language station "Radio Austral" 87.6MHz, dance tracks on "Raw FM" to name a few. Source, https://www.acma.gov.au/-/media/Licence-Issue-and-Allocation/Information/Word-Document/High-power-and-low-power-radio-open-narrowcasters-programming-and-broadcasting-data.doc?la=en - definitely not an exaggeration.

In addition, though the MW AM band is officially 522kHz-1602kHz, there are radios sold and marketed in Australia that have its AM band go to 1701kHz. Pioneer A/V receivers, for example VSX-932 and Toyota Camry's radio goes to 1701kHZ to name a few. You can receive in Sydney "The Voice Of Charity" on 1701kHz.

An observation, this is not numerology. Nevertheless, without mathematical proofs, adding the digits of the frequency of a radio station, if divisible by 9 is indicative of a 9kHz-spaced radio frequency. To illustrate for Sydney frequencies, RN on 576 kHz, adding the digits 5+7+6 =18 is divisible by 9. Another example 1701kHz, add the digits, 1 + 7 + 1 = 9, is divisible by 9. One final example 2GB at 873kHz, 8 + 7 + 3 = 18 which is divisible by 9.

One final point. I agree with about the carrier in an AM mode being wasted. I already stated that the carrier remains at a constant level regardless of the amplitude of its side bands.

I thank you for enriching the public at large about the capability of DRM. Please clarify whether a DRM transmitter can carry 3 or 6 signals on one tx, and the quality of a decoded DRM signal over long distances especially on the MW and SW bands.

Thank you,
Anthony of exciting Belfield


Commenting on digital radio
jonoburggraaf
16 August 2019 - 5:23pm
Hi All,
Because Macquarie isn't doing very well,i think they should get rid of Macquarie's Sport radio station in Melbourne that replaced Magic 1278.Magic was a great station and lots of people liked listening to it, particularly older people as they liked the music. Magic is really missed and I think that now would be the perfect opportunity to bring it back.
From Jono and ben
Macquarie Media struggles in a difficult market
Drano
16 August 2019 - 12:43pm
Knoxie sounding as good as ever on air, and a separate (windowed) booth for the newsreader at the new studios. Better than the "broom cupboard" at Stones Corner! Did they use the news intro with his v/o in it "also on iHeart radio" etc? John Knox returns to 4KQ
Peter Lewis
16 August 2019 - 10:36am
If I want all music, I'll use Spotify. Seems like they have totally given up! Grant Ed and Ash make way for more music at 2Day
madman
16 August 2019 - 10:35am
Colin Tyrus and many other highly respected journalists are well remembered for the establishment of this great news network. NewsRadio is 25 years old
StJohn
15 August 2019 - 11:39pm
Anthony,
Many AM stations use processors to try and sound like FM by boosting the high frequency audio because of the very poor high frequency response of AM receivers. This will particularly affect the SBR signal. X Digital in Perth only transmits music and some advertising but not much speech. There is plenty of bass.
The problem for broadcasters is that they can preview MP2, MP4 files and they sound fine, but once transmitted are poor sounding regardless of the bit rate.
As far as India goes, India does not have its population evenly distributed. The Government is trying to cover the whole of the country because it’s All India Radio is the only broadcaster allowed to transmit news and current affairs. They do separate the networks like the ABC local radio does. There FM commercial broadcast industry is tiny. http://www.asiaradiotoday.com/news/drm-association-radio-operators-india’s-agm shows that DRM+ is likely because it can transmit 3 programs on one transmitter. Two DRM+ transmitters can fit into a single FM channel. A main driver for DRM in India is the Emergency Warning System will save millions of lives from the floods of the dual monsoons per year.
As far as cars goes, they have only just started installing DRM in cars and have done it to 1.5 million cars in 18 months and they have only just started. An app has been written for the FM tuner in most Android phones which are much more popular than iphones.
The ACMA has already stated that they are only converting the remote and a few country AM licences to FM as the band is too crowded elsewhere. You can fit 6 DRM+ audio programs onto one FM transmission channel.
As far as Australia goes the cost difference between FM and DRM+ is no where as big as you claim as the single transmitter is used for both of each broadcasters’ programs. The only difference is the modulator and a content server to combine their pair of audio programs to fit into one digital stream. They can add coloured pictures for advertising and could also radiate an electronic text “newspaper” using Jounaline.
So, the cost is reduced because the AM transmitter is switched off as well as the FM transmitter. It can be replaced with a DRM+ transmitter of 1/ 10th of the power for the same coverage area. In remote areas such AM transmitters can be modified to DRM, however there is currently one commercial station on High Frequency (Short Wave) which can economically cover large remote areas. Converting it to DRM will give good stereo sound and it is easily tuned.
Your comment about tuning ranges is exaggerated. FM radios tuning below 87.5 MHz Lower FM frequencies were only used in Japan and the USSR. USSR is now testing DRM+ at a frequency around our analog TV channel 2. All digitally tuned AM receivers are selectable for 9 kHz spacing for 531 – 1602 kHz or is 530 – 1700 on 10 kHz spacing which is only used in the Americas. Much of Europe has no AM at all. No mobile phones virtually no DAB+ radios will receive AM at all.
Over 67% - 100 % of the power of an AM signal is wasted in the carrier. DRM does not have a carrier resulting in drop in electricity consumption. It uses COFDM just like our digital TV.

St John
Commenting on digital radio
Anthony The Koala
14 August 2019 - 2:02am
Dear StJohn,
Thank you for your insights.

I may have misled you on the sound of a radio station. When I was comparing the sound of 2GB, 2CH and NTS, I was referring to DAB+ version of the stations, not the actual analogue transmission where you were discussing the use of pre-emphasis at various frequencies and levels. I recall when 2UW was on the air whenever they played music, the hiss and crackles of the music track came 'to prominence' during soft parts of the music.

When I was referring to 2GB, 2CH and NTS, I should have referred to listening to these three stations on DAB+. Given that there is no pre-processing of the signals, I can say that the bitrate determines the fine detail of the heard broadcast. 2GB and 2CH broadcast at 128kbs. The quality of the same "newscasts" sound better than NTS at 32kbs. In other other words, the higher the bitrate, the more detail is heard in the timbre of the baseband signal. My apologies.

You do make a very valid point on the use of source audio files in broadcasting. Before the introduction of DAB and DAB+ where a radio transmission was only an analogue signal, it was acceptable to use lossy-coded files such as MP2 on 'cart' machines such as "Audiovault". The system was decode lossy file at studio then send to transmitter. The receiver decodes the analogue to the ears.

But using lossy audio files on a digital platform, the sound is awful. The system is a transcoding of the lossy file at the studio: decode lossy file at studio, then re-encode to lossy format. The receiver decodes the lossy formatted signal to analogue/listener's ears. The issue is that in lossy encoding, redundant pyshco-accoustic information is deleted at the original encoding of the audio file. Decoding the lossy file is acceptable. However transcoding lossy files results in a deteriorated signal.

Thus there may be another explanation for the awful sound of low rate 32kbs signals because the rebroadcast of a lossy file in the chain from the studio to the receiver results in a woeful sound. This is because re-encoding audio information that has already had its psyhco-accoustic signals removed, the transmitter's encoder is treating the decoded source audio as if there was psycho accoustic information when there is not.

The lesson for broadcasters is not to use lossy audio files. A former presenter on 2CH's Sunday evening program said that his station uses LOSSLESS audio files. It may also explain that the 32kbs station playing "lullaby" music sounded tinny when the high frequency components of the chimes and bells. If may also explain why a midnight-to-dawn presenter on 2GB several months ago was playing what sounded like music from YouTube. The sound quality was woeful. It appears that they don't play music from YouTube.

In regards to India's implementation of DRM, my intention was not to misrepresent. I look at the numbers. India has a population of 1.3 billion peole compared to 24 million for Australia. Australia is sparsely populated and what is broadcast in one rural town may not necessarily apply to another rural town. Such towns have smaller populations. Despite many rural towns broadcasting programs sourced from capital cities, the ACMA mandates local content. Local content in Wagga may well be different to local content in Young.

While India's DRM implementation involves 35 high power transmitters ranging from 20kW to 1MW, source https://www.drm.org/drm-digital-radio-broadcasting-in-india/ it is only implemented by India's public broadcast AIR ("All Air India"). There is no mention of the commercial broadcasters operating in India. At the moment, commercial broadcasting in India is not as lucrative as other media that broadcasters are struggling to break even, https://www.easymedia.in/commercial-radio-grown-india/.

It appears there there may not be a business case for FM radio in India to convert to DRM. Even with 1.8 million cars adopting DRM, it is only 1.8/218*100=0.8% of all 218 million registered cars in India according to economic analysts CEIC, source https://www.ceicdata.com/en/india/number-of-registered-motor-vehicles. On balance analogue radio is there to stay for a number of years.

Similarly for Australian rural towns, there may not be a business case for converting to DRM, lest DAB+ unless the cost of digital transmitters is similar to FM transmitters, subject to ACMA's engineering reports (mentioned earlier).

Put it this way, could a rural town of twenty to sixty thousand afford or contribute via advertising premium on its goods and services to a local radio station's conversion to DRM or DAB+. How many years will it cost to pay off/amortize the cost of DRM or DAB+ equipment? FM conversion where feasible may well be more economical, provided that it does not reduce audience coverage. That is unless the government is willing to subsidise the cost of digital transmission equipment.

What about consideration for broadcasters broadcasting below 88MHz on the FM band, beyond 1600kHz and the multicultural broadcasters on the VHF band at 150MHz even though it is used for marine communications, the ACMA paper did not consider these entities converting to digital. Don't you think that these entities would like to convert to digital?

A side note: most FM receivers will cover frequencies less than 88MHz. Many MW AM receivers will cover frequencies up to 1701kHz such as audio units installed in recent Toyotas. Some old Australian-made receivers covered AM till 1760kHz! UNSW's VL2UV broadcast on 1740kHz till 1986.

A note on switching off analogue transmitters. We all know from elementary electronics communications courses, that AM transmitters transmit both carrier and its sidebands. The amount of power in the sidebands is variable while the carrier remains constant. If the carrier signal was removed leaving only the sidebands, the AM transmitter would be cheaper to run. But most radios don't have synchronous detectors to decode DSB. Rather they have simple envelope detectors which are cheap.

So if there are market forces or a government mandate to switch off all analogue transmitters and convert to digital, it would reduce energy costs. For those who are concerned about global warming, the amount of reduced CO2 would be enormous, especially for those high-powered ABC transmitters!

On the other hand, AM and FM are ubiquitous compared to DAB+ and would be handy in the case of civil emergencies whether climatic, geological or other.

Final note: thank you for informing us on the 5G network which is 'painted' to us a panacea for wide band and speedy communications. You made the remark that (a) netcasting was more costly to implement than broadcasting, especially when dealing with multiple server (netcaster) to client streams and (b) 5G signals not being able to go through buildings. That is unless one has a 5G antenna and the signal is legally repeated inside the building.

It can be concluded that 5G is not the panacea for future digital transmission. Please when the issue of 5G for netcasting is mentioned again as a method in the future, we could all learn,

Thank you,
Anthony from exciting and dynamic Belfield

DAB+ turns 10 in Australia
StJohn
13 August 2019 - 7:59pm
Anthony,
Comparison of bit rates. This is not easy because broadcasters use processors to increase the loudness and “punchiness” of their audio. There is still a fixed maximum sound level prior to overmodulation. Processors boost and compress at different levels and frequencies is adjustable for each 1/3 of an octave. In FM there is 50 microsecond treble boost which can boost these frequencies by 15 dB. As a result the processor will boost the softer high pitched sounds but not the loud ones because this would overload the FM transmitter. This means that the received sound does not match the sound in the studio. In DAB+ and DRM there is no pre-emphasis, so unless a separate processor is used this extra boost at low levels will affect the Spectrum replacement of high pitched sound in the receiver. The conclusion is that you cannot compare the different data rates unless you know the audio is identical and only limited not processed. It is essential that the audio is only compressed once ie in the DAB+ encoder. If the audio has been stored in MP3 or MP4 the sound quality is significantly reduced.
There is a DAB+ station in the UK called Jazz FM who is allocated 32 kbit/s and they have done all they can to get the best quality. I am not advocating a wholesale shift to very low bit rates. I am suggesting any comparisons need to be made using double blind testing which is what the Fraunhofer Institute did when designing HE AAC v2.
With a few isolated places which have now dual FM licences, and capital cities, the rest of the country has a primary AM licence and an FM supplementary licence. Ie one transmitter for all their programs not a power guzzling AM transmitter and often on another site an FM transmitter. Nearly all these locations do not have the spectrum for FM. A better option for them is to transmit DRM+ which will carry 3 x 48 kbit/s audio streams plus slideshow, journaline and emergency warning systems. DRM+ using the old TV channels 0 – 2 will travel further than FM due to the lower frequency.
The European Union has just mandated digital reception in all new cars. You have misinterpreted my statement about India. They have recently completed a 38 very high power rollout of Medium Frequency DRM transmitters and 4 High Frequency DRM transmitters. The 1.5 million cars was in the last 18 months!
The Narrowcasters above 1600 kHz often cannot be received because most digitally tuned radios will not tune those frequencies. 150 – 174 MHz is mostly used by land and marine based 2 way radios not broadcasters.
Norway had to replace their aged FM network which is why the went to DAB+ nationally. Within 12 months the major network ratings had returned to normal. They also sold car adaptors which plug into the cigarette lighter, a stick on windscreen antenna and an FM modulator to access the existing car radio. It’s not as good as a factory fitted radio but it works. Check out “Pure Highway”.
There have been at least 3 studies comparing broadcasting with netcasting. Netcasting is much more expensive for the broadcaster and the listener. This is because each listener has to be served individually. 5G will not go through walls, buildings, terrain. So the NBN would have to be connected to a transceiver on each light pole. How would that work on a country road!
As it says at the start of the article DAB+ has been on air 10 years its about time we switched off AM and FM in capital cities because simulcasting is so wasteful. After all we switched off all analog TV for digital TV why not radio?
DAB+ turns 10 in Australia
Anthony The Koala
13 August 2019 - 7:36pm
There is the old adage that "...there is no such thing as a free lunch..." This applies to TuneIn. According to Radio Info's contributor Mr James Cridland, TuneIn is a site that aggregates radio streams, https://www., quora.com/What-is-TuneIn-Radio-and-how-does-it-work. The TuneIn app can be used on mobile phones, smart speakers and car audio systems supporting Tune In's system, https://en.wikipedia.org/wiki/TuneIn.

Tune In aggregates over one hundred thousand IP streams, and its apps are available as "free" or or "pro" or "premium". The "free" version displays advertising banners while the "pro" does not display adds and banners. The "pro" and "premium" versions allow for the recording of the IP stream while the "premium" allows for sporting programs and commercial-free music stations, https://help.tunein.com/what-is-the-difference-between-pro-premium-and-free-r1xeqA9uwM

What is the real price of Tune In? Going back to the "..no such thing as a free lunch..." Tune In appears to rely on the information the user and IP streaming service provider.

Thus the average 'intelligent' person in the age of information gathering and online shopping habits can determine what Tune In can do with the user and service provider information is to "commodotise" the data and sell that information to whovever wants to know who's listening to who, how much time is spent listening to a particular IP stream. Definitely more accurate than the diary system used in measuring audience ratings!

But alas, the BBC could not obtain data that the BBC wanted from TuneIn as other streaming services https://www.engadget.com/2019/08/12/bbc-to-pull-all-radio-services-from-tunein-uk/, so the BBC withdraws from TuneIn.

Lesson: if a broadcaster wants to know who's listening to its IP streams, it may have to offer some other incentives to the prospective listener in exchange for information. The broadcaster must make software compatible with smart speakers that don't have to rely on TuneIn. A broadcaster's web pages may have to include meta-search terms and negotiate with a search engine provider that inform the listener to listen to its IP stream.

Thus a terrestrial broadcaster relying on its licence area as its market area can reach out to a larger world-wide market. It could benefit advertisers as well. Imagine the "Blind Factory" ads targeting someone in LA.

Thank you,
Anthony from the exciting town of Belfield

BBC radio is leaving TuneIn
Anthony The Koala
13 August 2019 - 1:19am
Dear StJohn,
Thank you for averting me to the two documents, one on the stereo parametric transmission and the ACMA "issues paper" at https://www.acma.gov.au/theACMA/the-future-delivery-of-radio-services-in-australia

First, parametric stereo streams consist of a mono, L+R signal and a stereo image signal. The receiver reconstructs the L and R signals. I was surprised that NTS is now in 32kbs stereo! For a while it was in mono. I can make two remarks. The first remark is that when comparing newscasts which are broadcast on 2GB, 2CH and NTS, 2GB and 2CH both at 128kbs have a better timbre than NTS. The second remark, listening more carefully, one can still hear that metallic sound on the vocal content. The other station broadcasting at 32kbs stereo, whenever "lullaby-style" music is played, the high frequency components of the 'chimes' and 'bells' sound "metallic".

Conclusion, to reduce metallic/artifact high frequency sounds on low-bitrate streams, reduce the treble. Overall sound quality on stations broadcasting on at least 48kbs, though occasionally the metallic/artifact sound can be heard.

Second, the issue of future of the transmission of radio.

AM to FM conversion started in 2016. Converting to FM is subject to the availability of spectrum in a non-congested area subject to engineering reports p15 and no unreasonable interference caused by the proposed frequency, p16.

There is not a common or dominant approach to radio broadcasting. Perhaps mandating that all cars are equipped with radios of the digital kind, p14.

When it comes to DRM StJohn noted that India has adopted high-powered transmissions of DRM and that there are over 1.5 million cars equipped with DRM. The marketplace in India is in the order of millions.

Conversely, for rural towns in Australia with populations of 20 thousand, 60 thousand, there may not be a business case for a broadcaster to install a DRM transmitter compared to an FM installation. That's unless the economies of scale will reduce the price of DRM equipment, lest DAB+ equipment.

Let's not forget the hundreds of narrowcast broadcasters beyond the MW AM band of 1600kHz and the VHF frequencies at 150MHz. If we were to include only the community, commercial and National (ABC & SBS) stations into the DAB+ system, p17 engineering considerations p16 must be given to the allocation of spectrum including the scarce VHF frequencies for FM conversion, taking account of possible interference from other services including TV, p15.

Given that a large percentage of the radio audience is in a car, not all cars are equipped with DAB+ let alone DRM. It will be several years p6 before a majority of cars are equipped with DAB+ reception whether factory-fitted or retro-fitted.

So analogue radio will continue for a number of years, p17.

If all terrestrial broadcasting was to transfer to IP streaming, lets hope that the NBN and 5G networks will be able to handle the extra demands on the IP equivalent to Macquarie Media, our ABC and SBS, Southern Cross, Broadcast Operations Group.

Thank you StJohn,

Regards
Anthony of exciting and dynamic Belfield
DAB+ turns 10 in Australia

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