Thursday, March 09, 2006
HD Radio-Touchy subject for supporters.
My opinion, is that the HD radio is built on a whole series of false premises. There are rational solid reasons for this belief, and it seems to be shared by experiences and opinions of many, as shown by the responses on this discussion board,
in engineering publications, and responses to the FCC inquiry about HD Radio, MM Docket No. 99-325.
The facts are, that the FCC AM and FM signal protection specifications were based on experiment and calculation of 2 or more analog signals, not mixed digital and analog signals. To use the same signal standards for mixed analog and additional digital signals on adjacent channels is inacurate. To use the NRSC-5 mask for adjacent channel digital signals without proof that it the digital signals have the same intensity and interference potential as analog signals, is an incomplete, flawed, misrepresentation. As has been stated here, many times, by proponents as well as critics of HD Radio, the digital signal is 100 (or more?) times more powerful and pernicious then an analog signal of the same effective radiated power. That being the case, the digital signal creates more destructive interference. An occasional analog modulation spill over to an adjacent channels at approximately -40 dB, is not the same as a deliberate, continuous, high duty cycle digital signal on the same adjacent channels.
Using analog signal standards for mixed digital and analog signal propagation, may be inaccurate, incomplete, and inappropriate for the current station allocation system. New mixed signal interference studies should be made, including more listening tests on more types of radios, and with more typical listeners.
Secondary coverage is very usefull in the suburbs, when traveling between cities, and in emergencies. It should not be allowed to be reduced or destroyed by HD Radio.
HD Radio's harm to the many far outweighs the benefits and profits of the few.
There should be no rush to adapt a possibly defective and destructive standard, since, in the case of FM, there is a more rational and interference free alternative. Here is one: www.dreinc.com.
Perhaps an alternative AM system under development that would allow night time service and does not need special authorization, should also be examined and evaluated.
There should be no rush to adopt a standard, or endorse and approve an exclusive, expensive, proprietary system, until all alternatives are carefully and fully evaluated. If the wrong system is adopted as the only system for digital broadcasting, we are likely to be stuck with the flawed system's defects for a long time to come. It may totally fail, based on it's inherent flaws.
Haste makes waste.
The frequent claims that only HD Radio proponents have an exclusive patent on the 'truth" and "facts", while all others are ignorant of the "facts" are religious revelations I which choose not to subcribe.