5 ms·

This was true a decade ago. After several moves, I no longer have VHS player, Floppy disk drives, CRT, or radio. The only am/fm raidios are in our cars. If a

by mey 9y ago

This was true a decade ago. After several moves, I no longer have VHS player, Floppy disk drives, CRT, or radio. The only am/fm raidios are in our cars. If anything AM should be kept on, as you can broadcast farther on lower power or we should get younger generations into ham radio.

pedrocr 9y ago
>If anything AM should be kept on, as you can broadcast farther on lower power And receivers can be built with extremely simple parts so for the war/disaster situation it's a hedge against the complexity of our technology stacks.
- tzs 9y ago
  Actually you can build a simple FM receiver with the same parts you would use for a simple AM receiver, if you are willing to accept a fair amount of distortion. It would not be great for music, but would be OK for receiving news or weather or emergency instructions. One way to do this is to use something called an "FM slope detector" [1]. The idea is that you have a tuned circuit tuned to slightly above or below the carrier frequency of the FM signal. As the FM signal frequency moves around, it also moves nearer and farther from the center frequency of the tuned circuit, which means the output of the tuned circuit rises and falls. The result is that the frequency modulation of the FM signal gets turned into amplitude modulation of the output of the tuned circuit. You can demonstrate this if you have one of those cheap SDR dongles. Tell your SDR software to decode as AM, but tune to an FM broadcast station, and then start slowly moving the tuning up, and you'll find a point where the broadcast becomes quite intelligible. [1] https://www.electronics-notes.com/articles/radio/modulation/fm-frequency-demodulation-slope-detector-discriminator.php https://www.electronics-notes.com/articles/radio/modulation/...
  - keithpeter 9y ago
    On the transmitting side, there might be advantages to medium wave am for coverage compared to FM on 98/108 MHz. In the UK on long wave we have (or pehaps had) basically one large transmitter covering a large percentage of the population. https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station
bramzistor 9y ago
Except here in Belgium, they already switched off DAB in favour of DAB+. Now everyone can go out and buy a new radio again. Meanwhile, they also rally against planned obsolescence. How's that going to work? (luckely, they haven't yet switched of FM, that's scheduled for 2020)
- lb1lf 9y ago
  Same story in Norway - first they tried very hard to push DAB receivers, and I, being a firm believer in radio over TV for mass communication duly bought DAB radios for the car, kitchen, bathroom, living room hi-fi - then they (in fairness, very sensibly) switched to DAB+. Off to ye olde electronics shoppe I went again. I wonder how long DAB+ will last; I expect that sooner rather than later it will be scrapped for streaming via cellular networks - because doing so will be cheaper still than operating a DAB network. Sigh.
PoachedSausage 9y ago
The problem is that the average age of the engineers that have knowledge of high power AM at LF/MF/HF is probably well into the 50s and some of the actual transmitters are not far off that either.
- dwyerm 9y ago
  You might really enjoy this blog, then. The author has been watching both the decline and advancement of radio of the last few decades. It was interesting to see these big-iron transmitters being replaced by half-a-rack of solid state gear, but then still taking up four racks because of all the other gear. His last post is poignant, though: "...the absolute soul crushing mediocrity of automated programming is killing the entire industry." http://www.engineeringradio.us/blog/ http://www.engineeringradio.us/blog/
romaniv 9y ago
Radios are still sold in stores. Also, Phones and MP3 players often have FM radios. Heck, my best radio is probably my OP-1 synthesizer. The real "magic" of FM radio that it something that Just Works. You don't have to pay, you don't have to connect to some network, and it's something that worked since late 1930s. No matter what people say, any current digital radio formal will almost certainly obsolete in less than 20 years.
- beckler 9y ago
  How do you like your OP-1?
  - romaniv 9y ago
    Love it. It's one of the most well-designed electronic devices I ever owned. Rally fun to use. I think it's worth studying as an example of great user experience and designing for "emergent" features - even if you don't care about synthesizers all that much. Also, OP-1's synthesis capabilities are much deeper than it would seem from reading the manual or watching a typical review. And it has an amazing online community.
- IshKebab 9y ago
  Yeah but... Way more people have phones. Just send your emergency broadcast by SMS. There's even an official way to do that.

by mey 9y ago

pedrocr 9y ago

>If anything AM should be kept on, as you can broadcast farther on lower power And receivers can be built with extremely simple parts so for the war/disaster situation it's a hedge against the complexity of our technology stacks.

tzs 9y ago
Actually you can build a simple FM receiver with the same parts you would use for a simple AM receiver, if you are willing to accept a fair amount of distortion. It would not be great for music, but would be OK for receiving news or weather or emergency instructions. One way to do this is to use something called an "FM slope detector" [1]. The idea is that you have a tuned circuit tuned to slightly above or below the carrier frequency of the FM signal. As the FM signal frequency moves around, it also moves nearer and farther from the center frequency of the tuned circuit, which means the output of the tuned circuit rises and falls. The result is that the frequency modulation of the FM signal gets turned into amplitude modulation of the output of the tuned circuit. You can demonstrate this if you have one of those cheap SDR dongles. Tell your SDR software to decode as AM, but tune to an FM broadcast station, and then start slowly moving the tuning up, and you'll find a point where the broadcast becomes quite intelligible. [1] https://www.electronics-notes.com/articles/radio/modulation/fm-frequency-demodulation-slope-detector-discriminator.php https://www.electronics-notes.com/articles/radio/modulation/...
- keithpeter 9y ago
  On the transmitting side, there might be advantages to medium wave am for coverage compared to FM on 98/108 MHz. In the UK on long wave we have (or pehaps had) basically one large transmitter covering a large percentage of the population. https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station

bramzistor 9y ago

Except here in Belgium, they already switched off DAB in favour of DAB+. Now everyone can go out and buy a new radio again. Meanwhile, they also rally against planned obsolescence. How's that going to work? (luckely, they haven't yet switched of FM, that's scheduled for 2020)

lb1lf 9y ago
Same story in Norway - first they tried very hard to push DAB receivers, and I, being a firm believer in radio over TV for mass communication duly bought DAB radios for the car, kitchen, bathroom, living room hi-fi - then they (in fairness, very sensibly) switched to DAB+. Off to ye olde electronics shoppe I went again. I wonder how long DAB+ will last; I expect that sooner rather than later it will be scrapped for streaming via cellular networks - because doing so will be cheaper still than operating a DAB network. Sigh.

PoachedSausage 9y ago

The problem is that the average age of the engineers that have knowledge of high power AM at LF/MF/HF is probably well into the 50s and some of the actual transmitters are not far off that either.

dwyerm 9y ago
You might really enjoy this blog, then. The author has been watching both the decline and advancement of radio of the last few decades. It was interesting to see these big-iron transmitters being replaced by half-a-rack of solid state gear, but then still taking up four racks because of all the other gear. His last post is poignant, though: "...the absolute soul crushing mediocrity of automated programming is killing the entire industry." http://www.engineeringradio.us/blog/ http://www.engineeringradio.us/blog/

romaniv 9y ago

Radios are still sold in stores. Also, Phones and MP3 players often have FM radios. Heck, my best radio is probably my OP-1 synthesizer. The real "magic" of FM radio that it something that Just Works. You don't have to pay, you don't have to connect to some network, and it's something that worked since late 1930s. No matter what people say, any current digital radio formal will almost certainly obsolete in less than 20 years.

beckler 9y ago
How do you like your OP-1?
- romaniv 9y ago
  Love it. It's one of the most well-designed electronic devices I ever owned. Rally fun to use. I think it's worth studying as an example of great user experience and designing for "emergent" features - even if you don't care about synthesizers all that much. Also, OP-1's synthesis capabilities are much deeper than it would seem from reading the manual or watching a typical review. And it has an amazing online community.
IshKebab 9y ago
Yeah but... Way more people have phones. Just send your emergency broadcast by SMS. There's even an official way to do that.