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Comment by LeoPanthera | Hacker News Reader

I'm normally pro-digital over anything analogue, but broadcast radio is one medium, possibly the only medium, where analogue is better.

Digital compression simply doesn't cope with packet loss well enough to be practical. Even with a very weak FM signal, in emergencies you can still hear through the noise.

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In rural places in the US, it's terrible for television. Several years ago, it was mandated that TV stations switch from analogue to digital.

Now instead of getting a little static and being able to understand 100% of what is said and shown over the air; it's now 10% recognizable video 90% visual blocks, and 0% audio.

If the digital transition hadn't happened I think over the air television might have died by now. Analog broadcast used significantly more electricity and fewer and fewer people would be interested in the low quality signal. Stations might have decided the remaining viewers weren't worth the power cost.

That said I think streaming might kill it anyway.

Can you quantify the difference in electricity costs? Start with difference in Watts, guess 0.15$/kWh and then find $/year saved?

I bet the increase in quality and maybe the reliability or support costs for the old analog equipment were bigger factors.

...so how much would it have improved the reception if they kept using the same amount of power for digital?

What's the difference in power for analog vs digital TV broadcast?? Is that mostly because ATSC broadcasts moved towards UHF, and NTSC broadcasters preferred VHF when available? Or is there some other property of ATSC broadcasts that require lower energy?

Analogue video has to have a very high SNR at the receiver, because any noise is directly visible in the picture.

But with a digital signal, as long as you can distinguish individual bits, the picture is always perfect, so you can get away with a much lower signal strength.

Not just rural. In downtown Seattle, there's nearby stations I can't get at all. KIRO 7 (CBS affiliate) reception is unwatchably bad maybe half the time. Maybe it's the hills? I don't remember analog being this bad. I can pick up analog radio stations all the way from Vancouver.

At least television is designed for a static receiver. You can solve the problem with a better antenna and a suitable amplifier.

But radio is often received by moving receivers, for which there is no good solution, and analogue will always be better.

Digital doesn’t have to mean compressed. CD audio isn’t compressed; in fact the opposite, it’s expanded with fountain codecs. I don’t see why putting a digital signal of that approach on the air, wouldn’t result in better decoded SNR per bandwidth than analogue signalling. Emergency signals could add more error-correction per bit, to the point of even becoming non-real-time (i.e. your receiver would need to buffer the signal for a while before it could play any of it, but this would be fine, because the signal is likely repeating anyway.)

I mean, this is already how satellite (especially interplanetary satellite) communication works.

You can make digital transmissions cope with arbitrary amounts of packet loss, if you design your code accordingly.

It's not digital compression that the important bit, but the error correcting code: https://en.wikipedia.org/wiki/Coding_theory

Maybe the HD radio system was the way to go, digital with analog fall back.

At least on FM, on AM it doesn't work well for me.

HD Radio has some of the same disadvantages as digital TV — if you don't have a strong enough signal, it drops out.

The worse part, to me, is that it takes quite a long time for the HD signal to lock in. I had a brand new rental car last month with a brand new HD radio in it. It took upwards of ten seconds for some of the HD signals to lock in.

Radio stations (AM and FM) can improve this by going all-digital, instead of the hybrid technology almost all are running right now. But doing so not only excludes hundreds of millions of older radios, it reduces the coverage area. It's simply not worth the revenue hit, since in radio coverage area is everything.

On the plus side, I had a great Sony HD tabletop radio that I loved dearly. It had an iPod dock on top and if a song came on the radio that you liked, you'd press a button and the track information would be stored in a special playlist the iPod.

Then the next time you plugged the iPod into iTunes, it would match the information from the playlist and you could buy the song you heard on the radio from iTunes. It worked really well. I wish something like that existed for satellite radio.

I always wondered why apple never integrated something like this into their iPods and iPhones. AFAIK, the Bluetooth chips in the devices were capable of FM radio reception. It always seems like a perfect chance to get radio users into the iTunes ecosphere. Heck, there may have even been an ad-revenue opportunity? (Radio ads that trigger screen ads on the device?)

A while back a local station was having a problem and their analog signal was off but they were still transmitting digital. When I tuned in it was kind of funny because it was all static and then it faded into whatever music they were playing.

I've always wondered what full digital stations do, but for the reasons you've said I doubt there are any.

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