5 ms·

This is a good thing. AM needs to go. It's the least efficient way of transmitting audio. From a technical perspective 2/3 of the power of an AM transmission i

by iasay 4y ago

This is a good thing. AM needs to go. It's the least efficient way of transmitting audio. From a technical perspective 2/3 of the power of an AM transmission is wasted with the carrier and that has no information in it at all. If you have a 30kw transmitter, 20kw is just burned on crappy modulation scheme. Edit: fix typo

themodelplumber 4y ago
This comment illustrates why it's confusing to have the AM band and AM mode namespace overlap problem in the US. Parent is referring to the AM mode, not the band. However the band is unique and important in a lot of situations due to its propagation characteristics. Also since CW is considered AM...the mode comments may even be questionable...
- iasay 4y ago
  They are one and another when it comes to broadcast. Tied in unison until they are dead. As for the LF/MF/HF propagation modes, they are terribly unpredictable as anything other than line of sight. Groundwave <3MHz and lower, if you're lucky. Non-deterministic propagation is interesting if you're an amateur radio operator or SW DXer but it's not important and is quite frankly a liability if you have to rely on it or have a target audience. Sure you can bash out some CW to Tasmania from Europe and tell a great story but you're probably dead if you need it at a specific time when the sun is sleepy. For ref, ex CW operator. I use a UHF radio computer unit with a fruit on the back now.
  - themodelplumber 4y ago
    Strange to read LOS in there in combination with the "non-important" argument to follow it. LOS is non-important for all practical reasons when you have the very predictable ionospheric propagation effect and a favorite talk show. That WiFi exists...the more the merrier...
    - iasay 4y ago
      I tend to listen to my favourite shows on podcasts app these days.
      - themodelplumber 4y ago
        Hope you are enjoying it without any technical commitment. The other comments read like you burned yourself out for radio something good!
        iasay 4y ago
        Yeah that’s a whole another story though.
londons_explore 4y ago
More like 99% is wasted when you consider the modern alternative: a QAM encoded signal with many subcarriers with ECC sending efficiently compressed digital data. Do that, and you can transmit to the same population with far far less energy.
- iasay 4y ago
  That is a possibility. But the issue with that is complexity.
  - londons_explore 4y ago
    Note that modern compression[1] now allows decent fm-quality music or speech in just 375 bytes per second! That's fixed bitrate too! That means that compared to AM radio, you can have a 200x power reduction - or more likely, use the same power but far fewer transmitting masts, saving millions of $$$'s annually. > complexity Yes, you're right - but it's all software, so when you've done the one-time effort of writing said software, the complexity is 'resolved' - it's not like a complex circuit where every single device must have more components, more labour to assemble, more expense, etc. [1]: https://ai.googleblog.com/2021/08/soundstream-end-to-end-neural-audio.html https://ai.googleblog.com/2021/08/soundstream-end-to-end-neu...
herpderperator 4y ago
You mean the least efficient?
- iasay 4y ago
  Whoops not enough coffee today. Thanks for the prod - have corrected :)
foepys 4y ago
You can fashion an AM radio receiver from very basic parts and it needs very low power. Transmitting and receiving is very easy, although the transmitter needs more power. Digital radio is bad when it comes to components, for both transmitters and receivers. Receivers also have a very high power draw compared to AM radio. In case of a catastrophic event (like war) digital radio will be next to useless and analog will be king. Decommissioning a fully working system while Russia is reviving the cold war again, is foolish. Especially since renewables are coming up strong now and the power draw of transmitters in terms of ecological impact won't matter anymore quite soon.
- iasay 4y ago
  FM is no more complicated than AM to transmit and receive. Simple FM discriminators for receivers like pulse counters only require a few components. On the transmit side, it's a lot easier getting decent high power modulation on an FM transmitter than an AM one. The AM transmitter you tend to have to modulate the power to the final amplifier which requires huge great obsolete tubes running in semi-linear modes. The FM one you do the modulation further up the chain, be that at one end something digital or just a simple varactor and the final amps work entirely outside the linear region meaning low power dissipation with filtering on the output. Cheaper and simpler. Agree with digital radio concerns. That's absolutely no good for anyone. Analog may be king but don't be too romantic about it. If you've ever actually done any operating on any analogue radios you'll know what I mean. I spent 20 years designing and building them for fun.
  - skeptically 4y ago
    "FM is no more complicated than AM to transmit and receive." FM is simple compared to WiFi6, but its an order more complicated than AM. An AM receiver only needs a diode and a coil of wire. The diode can be a rusty blade. I dont think you can make an FM receiver without a transistor (which for me, as a former solid state guy is an order of magnitude more complicated than a diode)
    - Johnythree 4y ago
fortran77 4y ago
This is like saying we should tear down the Louvre because we can show all those paintings on a website.
- redox99 4y ago
  This is one of the wildest analogies I've ever seen.
  - fortran77 4y ago
    For some of us, AM medium-wave broadcast has a beautiful aesthetic.
Johnythree 4y ago
AM broadcasting on the Medium Wave band is pretty much the only way to cover the enormous distances in places like Australia, etc. Most FM transmitters also broadcast at high power levels, but as they are limited to line-of-site, they have very poor penetration into rural areas, forested areas, buldings, etc.
- iasay 4y ago
  Yeah aware of that. However I know someone who ran VHF repeaters out there because that was the only viable two way communications out there back in the 80s. He runs rural Wi-Fi now!

by iasay 4y ago

themodelplumber 4y ago

This comment illustrates why it's confusing to have the AM band and AM mode namespace overlap problem in the US. Parent is referring to the AM mode, not the band. However the band is unique and important in a lot of situations due to its propagation characteristics. Also since CW is considered AM...the mode comments may even be questionable...

iasay 4y ago
They are one and another when it comes to broadcast. Tied in unison until they are dead. As for the LF/MF/HF propagation modes, they are terribly unpredictable as anything other than line of sight. Groundwave <3MHz and lower, if you're lucky. Non-deterministic propagation is interesting if you're an amateur radio operator or SW DXer but it's not important and is quite frankly a liability if you have to rely on it or have a target audience. Sure you can bash out some CW to Tasmania from Europe and tell a great story but you're probably dead if you need it at a specific time when the sun is sleepy. For ref, ex CW operator. I use a UHF radio computer unit with a fruit on the back now.
- themodelplumber 4y ago
  Strange to read LOS in there in combination with the "non-important" argument to follow it. LOS is non-important for all practical reasons when you have the very predictable ionospheric propagation effect and a favorite talk show. That WiFi exists...the more the merrier...
  - iasay 4y ago
    I tend to listen to my favourite shows on podcasts app these days.
    - themodelplumber 4y ago
      Hope you are enjoying it without any technical commitment. The other comments read like you burned yourself out for radio something good!
      - iasay 4y ago
        Yeah that’s a whole another story though.

londons_explore 4y ago

More like 99% is wasted when you consider the modern alternative: a QAM encoded signal with many subcarriers with ECC sending efficiently compressed digital data. Do that, and you can transmit to the same population with far far less energy.

iasay 4y ago
That is a possibility. But the issue with that is complexity.
- londons_explore 4y ago
  Note that modern compression[1] now allows decent fm-quality music or speech in just 375 bytes per second! That's fixed bitrate too! That means that compared to AM radio, you can have a 200x power reduction - or more likely, use the same power but far fewer transmitting masts, saving millions of $$$'s annually. > complexity Yes, you're right - but it's all software, so when you've done the one-time effort of writing said software, the complexity is 'resolved' - it's not like a complex circuit where every single device must have more components, more labour to assemble, more expense, etc. [1]: https://ai.googleblog.com/2021/08/soundstream-end-to-end-neural-audio.html https://ai.googleblog.com/2021/08/soundstream-end-to-end-neu...

herpderperator 4y ago

You mean the least efficient?

iasay 4y ago
Whoops not enough coffee today. Thanks for the prod - have corrected :)

foepys 4y ago

You can fashion an AM radio receiver from very basic parts and it needs very low power. Transmitting and receiving is very easy, although the transmitter needs more power. Digital radio is bad when it comes to components, for both transmitters and receivers. Receivers also have a very high power draw compared to AM radio. In case of a catastrophic event (like war) digital radio will be next to useless and analog will be king. Decommissioning a fully working system while Russia is reviving the cold war again, is foolish. Especially since renewables are coming up strong now and the power draw of transmitters in terms of ecological impact won't matter anymore quite soon.

iasay 4y ago
FM is no more complicated than AM to transmit and receive. Simple FM discriminators for receivers like pulse counters only require a few components. On the transmit side, it's a lot easier getting decent high power modulation on an FM transmitter than an AM one. The AM transmitter you tend to have to modulate the power to the final amplifier which requires huge great obsolete tubes running in semi-linear modes. The FM one you do the modulation further up the chain, be that at one end something digital or just a simple varactor and the final amps work entirely outside the linear region meaning low power dissipation with filtering on the output. Cheaper and simpler. Agree with digital radio concerns. That's absolutely no good for anyone. Analog may be king but don't be too romantic about it. If you've ever actually done any operating on any analogue radios you'll know what I mean. I spent 20 years designing and building them for fun.
- skeptically 4y ago
  "FM is no more complicated than AM to transmit and receive." FM is simple compared to WiFi6, but its an order more complicated than AM. An AM receiver only needs a diode and a coil of wire. The diode can be a rusty blade. I dont think you can make an FM receiver without a transistor (which for me, as a former solid state guy is an order of magnitude more complicated than a diode)
  - Johnythree 4y ago

fortran77 4y ago

This is like saying we should tear down the Louvre because we can show all those paintings on a website.

redox99 4y ago
This is one of the wildest analogies I've ever seen.
- fortran77 4y ago
  For some of us, AM medium-wave broadcast has a beautiful aesthetic.

Johnythree 4y ago

AM broadcasting on the Medium Wave band is pretty much the only way to cover the enormous distances in places like Australia, etc. Most FM transmitters also broadcast at high power levels, but as they are limited to line-of-site, they have very poor penetration into rural areas, forested areas, buldings, etc.

iasay 4y ago
Yeah aware of that. However I know someone who ran VHF repeaters out there because that was the only viable two way communications out there back in the 80s. He runs rural Wi-Fi now!