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About alanh

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  1. There are many protesting the Sydney centric view of the ABC on Short Wave broadcasting You have no idea of how many listeners there are to Radio Australia or those mobile outside of Darwin/Alice Springs as does the ABC. The analog radio in Canberra along with Goulburn, Cooma, Young, Bathurst, Orange and Illawarra, so that as soon as you leave the limited coverage area of DAB+ broadcasts you have no radio at all. Canberra only has 390 thousand people compared to the smallest mainland State capital at 1.3 millon to Sydney at 4.1 million. The projected power is too low, however DRM would be a much better choice to cover the Southern Tablelands as well which is the current function of ABC Canberra. Alanh
  2. Just remember that the money to pay for the DAB+ transmitter for the ABC/SBS is coming from the termination of short wave transmissions in the Northern Territory which now have no radio outside of towns unless you use the VAST satellite to a fixed satellite dish. Useless in boats and moving cars. In addition Radio Australia Short Wave has also been terminated as well. It will also be used to pay for ABC/SBS transmitters in Darwin, Hobart and the Gold Coast. Remember you are getting DAB+ as an additional signal and you are not loosing AM and FM transmissions. Remember also the power proposed is half that from DTV in the same frequency band and is half that of the capital city DAB+ transmitters. Alanh
  3. There is a new second commercial mux being rolled out nationally at high power. It contains 2 HE AACv2 programs. They should not be calling it DAB+ because the error correction used for the whole mux is the one used for DAB which is less capable of removing errors. You can only really call it DAB+ if all the programs are HE AACV2 compressed and DAB+ error correction is used. That will make the reception more reliable. Ofcom's policy is leave it up to the broadcaster to see which compression they wish to use, which is why not all of the compression as mentioned in the article is HE AACV2. A DAB(+) channel is capable of carrying 1.792 Mbit/s (after overheads have been removed) which when divided by 28 gives 64 kbit/s. So provided they don't transmit pictures or too much text and they use HE-AACV2 the sound quality for all but the geeks will be fine. The ABC local radio uses 64 kbit/s HE AACV2 in stereo. The "DAB" channels will have to go mono which is common there. Alanh
  4. Slattery, This is unlikely. The main suppliers of overseas ABC programs is the UK which has been purely HD production for a long time as has the major networks in the USA. The UK does simulcast SD versions of their HD programs, but the downscaling occurs just prior to transmission.All UK HD transmission is MPEG-4 where as in the USA it is MPEG-2. It would cost them extra to make special SD version for the ABC. The cost of satellite time is related to the data rate. The data rate for SD MPEG-2 is about the same as HD MPEG-4. However the ABC rarely does this because it cannot afford the program rights for the original program let alone the satellite time so no live via satellite. The only live satellite programming is news which is distributed to many broadcasters from the same satellite at the same time which reduces the cost to an individual broadcater. Alanh
  6. The total available bandwidth is per transmission channel is the same as our, but the power level is very low to prevent interference with other DAB Mini-muxes. No mention of the bit rates or how many channels are not HE AACV2 as used in DAB+ but are MPEG1 level 2 as used in DAB. Alanh
  7. Nath85. If an microwave STL is used pointed at Mt Dandenong, it will not feed their AM transmitter at Lower Plenty. It has to be a separate Microwave link because the beam is too narrow to hit both sites. Many stations have abandoned microwave systems and use IP on dedicated lines from the telcos. The AAC encoding should only occur once and would be done at the studios. The DAB+ muxing with the other broadcasters will be done at the transmitter site. It has no effect on sound quality. It is purely switching between the program sources in turn. There is no advantage in using MPEG-1 layer 2 compression between the studio and the DAB+ transmitter, because AAC is more effficient and is required for transmission anyway. Alanh
  8. shows the plan of the Government and Commercial radio stations The plan is progressing Alanm
  9. Nick Xenophone's bill to restart short wave broadcasting went to a committee, which is to report on 10th May Alanh
  10. Snoopy, The point is that there is no audible difference between any of the connection systems be it HDMI, optical or coaxial. Alanh
  11. Digital only stations Analog+digital stations The commentators have not picked up Digital only My Perth Digital Cumulative audience 29,000 is number 2 in Perth Analog + digital highest cumulative audience only beaten by the highest rating station MIX 94.5 at 33,000. Part of the reason is no advertising except some self promotion and advertising CRA's app. Just for the record the bit rate is 48 kbit/s Alanh
  12. This system has now been selected by the ATSC for the new DTV standard in the USA ATSC3.0. Audio is sent as objects with names Note the data rate is half AC3 which we use on the HD TV channels here. Alanh
  13. I saw the original movie in a movie theatre when it was first released. I have the DVD but some of the movie has been removed, Don't know about the blu-ray, maybe they have copied the entire movie this time. Alanh
  14. MLXXX, Another total lack of knowledge. Having lost on bit rate now jitter is the new enemy! The data on all digital distribution systems from the player or receiver use multiplexing. This means sending an identification followed by the left signal data, then followed by identification data and the right channel data. To allow both signals to share one pair of wires or fibre the signals are stored in memory and the transfer rate doubled. At the receiving end the data is stored in memory to be read out at the original rate. So end to end there is no change in sample rate. HDMI is the same but the multiplexing also includes the 3 signals required for colour images. HDMI system is capable of extremely high transfer rates for the huge amount of data to be transfered because the standard requires all compression to be removed. If jitter was a problem it would be a much greater problem for the images. Some more imagination like yours. Lots of audiofiles have "golden ears" like those who think that you need to use oxygen free cables and gold plated connectors. They think it because of the price not because of the sound. So the player or receiver has to decompress the signal. Anybody who doubts this can compare the sound by the various outputs and come to their own conclusions with their own ears, not the internet falsehoods by people with financial or other axes to grind. Jitter is not a problem in studios because a common clock signal is sent to all digital equipment, just like for video signals in TV studios. Mechanical devices such as blu-ray players playback with varying speed. This resulting change in frequency is removed by writing the data into memory and reading it out at the desired rate. The motor control system is also locked to that desired rate to prevent the memory emptying or overflowing. For a very long time frequency ranges of audio equipment particularly speakers has been the range of frequencies which can be reproduced where the output power has not varied by more than 3 dB, which is inaudible on program, not tone. Alanh
  15. Snoopy8 PCM and HDMI will be identical. HDMI interface for vision and sound totally uncompressed as is PCM and the data is identical. The only difference is that the data rate of transfer is faster to allow for the inclusion of video on the same wires. MLXXX, Your are at it again spreading unqualified opinions of others which are not your own. Acme audio is there to sell their equipment and are hardly unbiassed. Try detecting 0.1 dB at 15 kHz. Can you actually hear 15 kHz and a change of 0.1 dB? Remember that an increase of 10dB doubles the loudness of the midrange frequencies. Alanh